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Climate change is driving natural systems beyond their limits

October 14, 2024 by ZCA Team Leave a Comment

This article is also available in Spanish.

Key points:

Emissions of greenhouse gases in the post-industrial era have significantly altered the planet’s climate, resulting in extreme weather anomalies across the globe.
While extreme events such as droughts, storms, heat and unpredictable precipitation are natural phenomena, the increased severity and magnitude with which they are occurring under climate change exacerbates their impacts on humans and natural systems.
Changes in climate and land use are making animals’ and plants’ habitats unlivable, forcing them to migrate or adapt, or otherwise become extinct. This has knock-on effects for human livelihoods.
Natural systems face pressure from both climate effects, such as heat, and human effects, such as land-use change, with the combination of these stressors intensifying challenges.
Environmental changes in one system are triggering reactions in other systems, with cascading effects that threaten the stability of the planet’s climate systems.
Scientists are increasingly worried that climate change is edging natural systems closer to dangerous positive feedback loops that fuel more extreme weather and environmental degradation, in turn accelerating the pace of global warming.
Every increment of warming increases the chance of dangerous positive feedback loops, the effects of which – including the loss of crucial global carbon sinks and weather-modulating ecosystems – are often irreversible.
Atmospheric concentrations of greenhouse gases have reached unprecedented levels in recent years, and deforestation and land degradation continue to erode the capacity of the land to absorb carbon dioxide from the atmosphere.
To reduce detrimental warming to humans and nature and meet Paris Agreement targets of limiting warming to 2°C or 1.5°C with little or no ‘overshoot’ – where temperatures temporarily exceed the target before dropping back – “rapid and deep, and in most cases immediate” reductions in greenhouse gas emissions will be needed across all sectors.

Climate change is intensifying weather anomalies

Since the discovery that burning carbon-rich materials such as coal, oil and natural gas can generate heat to power industrial activities, humanity has released billions of tonnes of carbon that had been stored in the Earth for millions of years into the atmosphere. This massive and continuous release of carbon dioxide and other greenhouse gases, including methane, has significantly altered the planet’s climate. Since the onset of the Industrial Revolution, the Earth’s average temperature has risen by approximately 1.2-1.3°C – driven largely by the continuous and unchecked accumulation of these emissions.¹

The speed of global warming has ramped up considerably over the last three decades, and particularly since 2015, attributed to increased fossil fuel emissions, deforestation and changes in land use. Despite pledges made to curb emissions in the Paris Agreement, where most countries worldwide agreed to limit “the increase in the global average temperature to well below 2°C above pre-industrial levels” and to pursue efforts “to limit the temperature increase to 1.5°C above pre-industrial levels” by the end of the century, the last 10 years have been the hottest on record. 2023 is officially the hottest year on record since record-taking began.

This planetary warming is intensifying weather anomalies across the globe, resulting in more frequent and severe storms, heatwaves and droughts, and unpredictable precipitation patterns. While droughts, storms, heat and extreme precipitation are natural phenomena, the increased severity and magnitude with which they are occurring under climate change exacerbates their impacts on humans and ecosystems (Figure 1).

Extreme heatwaves are now occurring at almost five times the frequency they were occurring during pre-industrial times and are anticipated to further increase in frequency by 8.6 times at 1.5°C of warming, 13.6 times at 2°C of warming, and 27.4 times at 3°C of warming. Every increment of warming amplifies the climate risks to ecosystems and humans.

Paris Agreement targets

The 1.5°C target, endorsed by the Intergovernmental Panel on Climate Change (IPCC), marks a crucial threshold beyond which the impacts of global warming become increasingly severe for both humans and the environment. This target was determined based on the risks posed by increasing temperatures on a range of factors, including food security, extreme weather events, health, biodiversity loss, water supply and economic growth.

February 2023 to January 2024 marked the first 12-month period in human history where average global temperature rise exceeded 1.5°C. Although breaching the Paris Agreement target would require average annual temperatures to stay above 1.5°C for at least 20 consecutive years, the fact that we are already seeing consecutive months exceed this threshold suggests that we are approaching this critical point.²

Even though the 1.5°C target has not yet been breached, we are already experiencing the consequences of global warming. Though substantially less risky than higher global warming levels, the target of 1.5°C should not be viewed as a definitive ‘safe’ limit – there is no universally ‘safe’ level of global warming. What is considered an acceptable level of warming will be highly subjective. For example, extreme heat in 2024 alone has had tragic consequences for people and nature: in Saudi Arabia, during the Hajj pilgrimage to Mecca, 1,300 people collapsed and died as temperatures soared in June, while almost 40 monkeys drowned in a well in India in a desperate effort to reach water as lakes have dried up the same month.

Current policies place us on a trajectory to reach 2.7°C of warming by 2100. The expected impacts would not increase linearly, with certain effects becoming disproportionately severe. For example, the chance of having a major heatwave increases to 30% under 1.5°C of warming, but more than doubles to 80% at 3°C. At local levels, the impacts of a warmer world are also non-linear: as the global temperature reflects an average from across the world, actual temperatures in specific locations vary significantly, from much lower to much higher than the global average.

This variation means that the impacts of warming are unequally distributed – actual temperatures in specific regions can vary greatly – some places may warm much faster or slower than the global mean. For example, average July temperatures in 2023 for parts of northern and eastern Canada – which experienced record-breaking forest fires that year – were up to 7°C higher than the 30-year average.

Fig. 1: Risks to land and ocean systems with increasing levels of global warming

Source: Figure SPM.3, IPCC Sixth Assessment Report, 2022. Circles from least to most indicate increasing levels of confidence. Colours from palest to darkest indicate increasing risk.

Climate and land-use changes are critically altering ecosystems and affecting species in a number of ways, resulting in biodiversity loss (Fig. 1). Estimates suggest that wildlife populations have declined by 69% over the past five decades due to human impacts. Future climate change could cause abrupt and irreversible species loss this century, affecting marine ecosystems as early as 2030 and land ecosystems around mid-century.

Reduced biodiversity weakens ecosystem resilience to climate impacts and also reduces ecosystem services – i.e. the benefits that humans derive from natural ecosystems – such as food security, climate regulation and carbon sequestration. Though difficult to quantify because of the innate complexity of natural systems and their interactions, ecosystem services worldwide are estimated to be worth USD 150 trillion a year – or twice global GDP in 2021, and at least 1.5 times 2023 GDP.

The relationship between climate and biodiversity is deeply intertwined

The impacts of climate change on natural systems are complex and interconnected, making them difficult to predict and manage. Ecosystems face pressure from both climate effects, such as heat, and human effects, such as land-use change, with the combination of these stressors intensifying challenges for natural systems. Climate change is driving species to shift their geographic ranges as they seek more suitable habitats in response to changing temperatures, altered precipitation patterns and disruptions to their ecosystems.

As temperatures rise, marine and land species are moving poleward or to higher elevations to find the conditions they need to survive, or otherwise risk extinction. Shifts in species’ distributions can lead to new interactions between species and their environments, with potential knock-on effects for human livelihoods.

Marine migrations and mortality: lobsters, sardines, cod and anchovies

For example, climate change-driven increases in ocean temperatures are pushing American lobsters northward along the US coast, disrupting local fishing industries. Warmer waters along the coast of Northwest Africa are driving sardines northwards, presenting a risk to millions of people in the region that rely on these fish for food security. On the west coast of South America, warmer ocean temperatures are shifting anchovy populations, thereby threatening a globally important commercial fish industry. In these situations, fishing pressure under climate change could exacerbate the stress on fish populations that are already struggling to adapt to new environments, potentially leading to overexploitation and further declines in fish stocks.

For extreme events with a sudden onset, such as heatwaves, some species may not be able to migrate or adapt quickly enough as they are pushed beyond their thermal tolerance limits, i.e. the temperature range within which a species can survive and function. Marine heatwaves in 2014-16 and 2019 in Alaska drastically disrupted Pacific cod populations, resulting in the closing of the fishery – Alaska’s second-largest commercial groundfish fishery – in 2020.

In the Mediterranean Sea, climate change is increasing the frequency and intensity of marine heatwaves, leading to widespread mass mortality events of marine organisms. From 2015 to 2019, the Mediterranean Sea experienced five consecutive years of mass mortality events, affecting a vast range of marine habitats and species, posing a severe threat to the functioning of its ecosystems.

Coral bleaching: too hot to recover

One of the most striking examples of climate change-induced mass mortality is warm-water coral reefs, which are increasingly facing mass mortality from human-caused marine heatwaves (Figure 1). Between 2009 and 2018, around 14% of corals from the world’s reefs had been lost, an amount larger than Australia’s coral reefs, largely due to bleaching, where corals expel the symbiotic algae that they depend on for existence in response to high water temperature, ultimately resulting in death if the warm water conditions persist.

Though corals can recover if water temperatures cool quickly enough, the increasing frequency of heatwaves due to climate change means that the corals’ windows for recovery between heatwave events are getting smaller, potentially leading to extinction. At 1.5°C of warming, estimates suggest 99% of coral reefs could be lost, with no coral reefs existing at 2°C.

For humans, this means the loss of critical ecosystem services, such as coastal protection, food resources and recreation. Coral reefs reduce wave energy by up to 97%, safeguarding 5.3 million people and USD 109 billion in GDP per decade. Reef tourism is valued at USD 35.8 billion a year,³ while reef-associated fisheries are valued at USD 6.8 billion.⁴

Heat on land: mass mortality of flying-foxes, birds and howler monkeys

On land, mass mortality events from heatwaves have been recorded in flying-foxes – bats that eat fruits and nectar. Flying-foxes play a crucial role in ecosystems by pollinating plants and dispersing seeds over large distances in their native habitats across South and Southeast Asia, Australia and East Africa. This helps maintain plant biodiversity and regenerate forests. They are also critical pollinators for commercially valuable foods, such as durian fruit. Despite their mobility, flying-foxes are extremely sensitive to heat stress: during the 2019-2020 summer in Australia – one of the hottest on record, made worse by climate change – at least 72,175 flying-foxes died from heat stress.

Mass mortality events on land have also been recorded elsewhere: an extreme heat event in South Africa in 2021 killed more than 100 wild birds and bats. Heatwaves in Mexico in 2024 caused the death of over 200 howler monkeys in the wild. Howler monkeys are important seed dispersers, particularly in forests disturbed by humans where they help to restore degraded habitats.

Drought: mass animal mortality induced by complex, additive effects

Prolonged dry spells are becoming more common in South America: over the 10 years between 2005 and 2015, three once-in-a-century droughts – or megadroughts – occurred in the region. Severe drought in Colombia in 2014 is reported to have caused the mortality of at least 20,000 animals, including wild pigs, deer, crocodiles and tortoises. The interplay of land-use change – particularly deforestation – and human-caused climate change is intensifying the impacts of the drought: deforestation in Brazil and Bolivia has aggravated drying in Colombia by changing the patterns of moisture cycling by forests across the region.

Declining pollination: a threat to food security

Pollination is a critical ecosystem service for humans, with the annual contribution of pollinators to global agricultural production and food security estimated at more than USD 500 million. Changes in climate are also disrupting the finely tuned relationships between insect pollinators and the plants they pollinate by altering the timing of flowering and pollinator activity. This creates a mismatch that can reduce pollination efficiency, with impacts on food security and prices.

Bumblebees in Europe and North America are declining due to climate change, among other factors. This decline is threatening essential pollination services and could lead to an ‘extinction vortex’, where the loss of bumblebees negatively impacts the plants they pollinate, further endangering both species. Further studies indicate that bumblebees will continue to face declines with climate change. More widely, a study on 38 globally distributed insects projects that up to two-thirds could become extinct this century. According to the IPCC, three times the number of insects will lose more than half of their climatically suitable ranges at 2°C of warming compared to at 1.5°C.

Dangerous feedback loops that perpetuate warming

Environmental changes in one system may trigger reactions in other systems. For example, climate change is increasing the likelihood of wildfires by creating hotter, drier conditions and extending the fire season, all of which make ecosystems more vulnerable to burning (Fig. 2). Forests, which are estimated to cool the earth by 1°C, play a crucial role in global carbon storage and are increasingly threatened by wildfires.

Climate-induced drying is transforming forests into highly flammable tinderboxes, increasing their vulnerability to wildfires. As prolonged droughts and elevated temperatures reduce soil moisture and dry out vegetation, forests are becoming less efficient at sequestering carbon and more prone to fires. These fires not only devastate vast areas of forest, thereby reducing their ability to absorb carbon, but also release stored carbon back into the atmosphere, further amplifying global warming. This creates a dangerous positive feedback loop, where rising temperatures fuel more extreme weather and environmental degradation, which in turn accelerates the pace of climate change.

Fig. 2: Illustration of a forest fire feedback loop

Source: World Resources Institute, 2020.

If the feedback loop is not stopped, the system could reach a critical threshold where a small change can trigger a significant and potentially irreversible shift in the system’s behavior or state, called a ‘tipping point’. Once a tipping point is reached, the system may undergo rapid changes that are difficult or impossible to reverse, even if the original trigger is reduced or removed (see fig. 3).

Fig. 3. Visualisation of a tipping point

Source: Rate-induced tipping in natural and human systems, 2023.

Figure 3 represents a landscape where the trough shows the stable ‘base state’ or natural condition of the system, the ball shows the system’s current state and the vertical red line shows the threshold. If the ball, which represents the system, is to the left of this threshold, it rolls into the trough and returns to its stable natural state. If the ball rolls over the hill to the right and crosses the threshold, it rolls away towards a new state.

Tipping points can occur either quickly or slowly depending on the system. Fast-onset tipping points happen within years or decades after crossing a critical threshold. For example, the transformation of forest into savanna due to wildfires and drought. Slow-onset tipping points develop over much longer timescales, such as centuries. Here, a system might exceed a critical threshold without immediately transitioning into an alternative stable state, but the change eventually becomes unavoidable over time. An example of a slow-onset tipping point is the thawing of permafrost or ice sheets.

Runaway wildfires in Canada

Though wildfires are natural phenomena, they are becoming larger and more frequent – fires are burning almost double the amount of forest that were burning two decades ago. Canada experienced devastating forest wildfires in both 2023 and 2024, with 2023’s extreme wildfires found to have been made more than twice as likely due to climate change. The 2023 forest fires are believed to have released around 640 million tonnes of carbon, or about the same annual emissions from fossil fuels in a large industrialised nation.

Drought, fire and beetles in the US

A warming climate is causing more tree mortality in the western US from increased fire, drought and insect outbreaks. Warm conditions during the 2012-14 drought in California – aggravated by human-caused warming – not only reduced tree resilience but also increased populations of bark beetles, which infested ponderosa pine trees and increased their mortality by almost 30%. This highlights the intricate interplay between climate and ecosystems and how climate-induced changes can disrupt ecosystem balance and have cascading effects. It is estimated that every 1°C increase in local average temperature increases ponderosa pine mortality by 35-40% due to the additive effects of climate and beetles.

Fire in the Brazilian Pantanal

Wildfires in 2024 in South America’s Pantanal Wetland – the world’s largest tropical wetland and one of the most biodiverse regions on earth – have burnt more than 13% of the biome. The fires were fuelled by climate change, estimated to have made these fires 40% more intense and 4-5 times more likely. If global warming reaches 2°C, fire conditions like these in the region will become twice as likely. In addition to threatening species survival and human livelihoods, the cascading effects of disruptions such as these threaten the stability of the planet’s climate systems.

Deforestation, fire and drought in the Amazon

Scientists are increasingly worried that the effects of drought, wildfires and deforestation in the Amazon – the earth’s largest rainforest – may cause it to enter a dangerous positive feedback loop, potentially leading to a sudden tipping point, transforming into an alternative state such as a savanna.

This change would result in the irreversible loss of a major carbon sink – as once a certain level of damage is done, the forest will not be able to regenerate and recover – potentially releasing up to 90 billion tonnes of carbon dioxide, more than double annual emissions from fossil fuels.

In some parts of the Amazon, particularly in the eastern region where deforestation rates are highest, the forest is already releasing more carbon than it can absorb. An Amazon tipping point would also mean the loss of a critical modulator of regional climate, with every country in South America, apart from Chile which is shielded by the Andes, benefitting from the moisture generated by the Amazon.

Alarmingly, the Amazon has already lost up to 15% to 17% of its forest area. Scientists estimate that the Amazon could reach a tipping point once 20-25% of native forest is lost. Other estimates suggest that a tipping point could be reached by 2050, corroborated by another analysis that suggests that the region could experience severe ecological disruption by mid-century, compromising the capacity of the forest to store carbon.

Glacier melt in the Andes

Glaciers gradually form as snow accumulates and compacts over centuries. They typically grow during winter and melt in warmer seasons, with the meltwater providing a water source that is replenished during glacier growth. However, rising global temperatures are causing glaciers to shrink faster than they can regenerate. As glaciers retreat, the meltwater volume increases until reaching a tipping point, beyond which it declines until it stops as the glacier eventually disappears.

Tropical glaciers in the Peruvian Andes are highly sensitive to climate change. Between 2000 and 2016, the area covered by glaciers in Peruvian Andes shrank by almost a third, attributed to a combination of climate change and the intense El Niño of 2015/16.⁵ Meltwater from glaciers is a critical resource for drinking, irrigation and hydroelectric power and therefore has wide-ranging consequences for both urban and rural populations in the region.

Permafrost and ice sheet melt in the Arctic, Greenland and the Antarctic

The Arctic is warming almost four times faster than the global average. This is leading to the melting of permafrost – a layer of soil rich in organic materials that has been frozen for many years – potentially causing a dangerous positive feedback loop. As permafrost thaws, microbial activity causes the significant release of greenhouse gases, including carbon dioxide and methane, which have been trapped in the frozen ground for millennia.

The release of these gases contributes to further warming of the atmosphere, which in turn accelerates the thawing of permafrost. This cycle can lead to increasingly rapid permafrost degradation, amplifying global warming and exacerbating climate impacts worldwide – it is estimated that Arctic permafrost holds up to 1,600 billion tonnes of carbon, about twice the amount of carbon present in the atmosphere today.

Of particular concern is the release of methane from permafrost, which is a potent greenhouse gas with a global warming potential that is 28-36 times higher than carbon dioxide.⁶ At just 1.5°C of warming, there is high confidence that the risk of permafrost degradation is ‘high’, increasing to ‘very high’ at just over 2.0°C of warming. Permafrost thaw also comes with an additional risk: it releases pathogens that may pose significant health risks to humans and animals, as was the case with an outbreak of anthrax disease studied in 2020.

The Arctic is also experiencing a reduction in sea ice extent due to rising global temperatures. This loss of sea ice contributes to a dangerous feedback loop: ice reflects sunlight, but as it melts, the darker ocean absorbs more heat, thereby accelerating warming. Scientists estimate that an Arctic sea ice tipping point could be imminent – at between 1°C and 3°C of global warming. Similar estimates have been made for the Greenland ice sheet and West Antarctic ice sheet.

The collapse of these ice sheets will increase sea levels globally, devastating coastal areas in the absence of concerted adaptation efforts. With anticipated warming this century, the ice sheets are expected to continue melting, but as these sheets grow much slower than they melt, this could result in a lag response – meaning they will continue to melt even once temperatures stabilise. Their melting may not be reversible this century and we are likely to still be locked into several meters of sea level rise.

The collapse of a critical Atlantic Ocean current

Another example of a crucial tipping point is the collapse of the Atlantic Meridional Overturning Circulation (AMOC) – a critical ocean current system that modulates global climate by transporting heat, freshwater and carbon. If the AMOC slows down and collapses, it would result in an irreversible change to global climate, including disrupting rainfall patterns in the Amazon, with catastrophic consequences for global carbon cycling as well as agricultural production and food security from decreased ocean productivity and changes in weather patterns. According to climate scientist Tim Lenton, a collapse would cause changes to the earth’s climate that would be “so abrupt and severe that they would be near impossible to adapt to in some locations”.

The AMOC has weakened since industrial times – with a significant contribution from human-caused warming – and is likely to continue weakening this century. However, it is debated how soon a complete collapse could occur. One analysis estimates that it is concerningly close – by 2057 – with another analysis also suggesting that the AMOC is on course for reaching a tipping point in a century’s time or potentially even sooner.

Overshooting Paris Agreement targets

The term ‘temperature overshoot’ is used by the IPCC to describe scenarios where global warming temporarily surpasses a target level, typically 1.5°C to 2°C, before eventually declining back to that level. Temperature overshoot scenarios are common in climate models: according to the IPCC’s “Global Warming of 1.5°C” report, 90% of the pathways that aim to limit warming to 1.5°C by 2100 involve a period of overshoot.

Scientists warn that temperature overshoot poses a risk to species through prolonged exposure to temperatures beyond their historical tolerance limits – that is, the environmental limits within which they have adapted over many years. This extended exposure can lead to increased stress, reduced resilience, and, in some cases, irreversible damage to ecosystems and extinction of species – even once global temperatures begin to decline back to a target temperature following a peak in warming during an overshoot. The risks are especially high for tropical ecosystems, such as the Amazon and the Pantanal, and tropical coral reefs, where species are particularly sensitive to temperature changes.

Achieving a 1.5°C limit with minimal or no overshoot requires rapid and significant reductions in emissions, with limited carbon dioxide removal (CDR), such as reforestation or bioenergy with carbon capture and storage (BECCS). On the contrary, pathways that delay emissions reductions are more likely to overshoot the target, necessitating greater reliance on large-scale CDR to lower global temperatures by the century’s end – which comes with various risks and uncertainties.

The IPCC warns that climate-related risks are higher if global warming overshoots 1.5°C compared to if warming gradually stabilises at 1.5°C. The longer emissions cuts are postponed, the more we risk exposing ecosystems and human populations to severe climate impacts over the coming decades, sometimes with irreversible consequences.

Solutions are available to limit catastrophic warming

Limiting detrimental warming to humans and nature to meet Paris Agreement targets of keeping warming to 1.5°C with little or no overshoot, or to 2°C, requires “rapid and deep, and in most cases immediate” reductions in greenhouse gas emissions in all sectors.

Energy-related carbon dioxide emissions reached unprecedented levels in 2023, and atmospheric carbon dioxide concentrations in recent years were at their highest in 4.5 million years. Methane concentrations in the atmosphere have been rising “dangerously fast” since around 2007, and have reached record levels in recent years. As the earth continues to warm, the ocean and land will become less effective sinks for slowing the rate of increase of greenhouse gases in the atmosphere, undermining the planet’s natural ability to mitigate climate impacts.

Deforestation from land-use change – primarily from agriculture – and rising temperatures means that forests are losing their capacity to sequester carbon – an ecosystem service valued at up to USD 135 trillion. If uncurtailed, deforestation and land degradation will continue to release carbon dioxide and erode the capacity of the land to absorb carbon dioxide from the atmosphere. At the same time, land-use change, including deforestation, accounts for around 10% of global greenhouse gas emissions,⁷ making it a significant contributor to climate change.

The most efficient and affordable way to cut emissions is by reducing dependence on fossil fuels and transitioning to renewable electricity. To meet the 1.5°C target, the IPCC recommends that coal usage must be eliminated, and oil and gas consumption reduced by 60% and 70%, respectively, by 2050.⁸ Increased electrification with nearly all power from zero or low-carbon sources is essential.

Reducing emissions from methane, a short-lived gas with a high global warming potential, is one of the quickest and most effective ways to slow global warming. Addressing methane sources such as pipeline leaks and abandoned oil and gas wells, and introducing technologies for mitigating livestock methane, could cut human-caused methane emissions by up to 45% by 2030. This could prevent nearly 0.3°C of warming by the 2040s, leading to significant health benefits and savings. To keep warming below 1.5°C, the IPCC recommends a 34% reduction in methane by 2030. Existing technology can reduce methane emissions from fossil fuel operations – which contribute around 40% of human-caused methane – by 70%, according to the International Energy Agency (IEA).

If countries and companies do not reduce their fossil fuel production, they risk increasing the costs of achieving a just and equitable energy transition as well as diminishing returns on investments and USD 1.4 trillion in stranded assets.

Renewable power is becoming more and more accessible: costs from wind and solar have been falling since 2010, reaching record-low levels in recent years and making them increasingly competitive with fossil fuels. In 2022, 85% of added global utility-scale wind and solar capacity was more affordable than fossil fuel alternatives. In 2023, additions of renewable energy – particularly solar photovoltaic – grew at the fastest rate in the past two decades, by almost 50% compared to 2022. To meet the 1.5°C target, rapid renewables deployment of around 1,000 GW per year until 2030 will be necessary.

Restoring degraded lands, preventing further deforestation and planting forests can significantly enhance carbon sequestration, improve resilience to climate impacts and help stabilise the global climate. For example, forests managed and protected by Indigenous People in the Amazon between 2001 and 2021 removed 340 million tonnes of carbon dioxide from the atmosphere each year – more than the fossil fuel emissions of the UK in 2022. Forest restoration and protection are recognised by the IPCC as key to limiting global warming to 1.5ºC or well below 2ºC and come with various co-benefits, including supporting biodiversity, improving air and water quality, flood control and reversal of land degradation, if managed properly.

1
The range of 1.2-1.3°C represents a five-year average.
2
The point where 1.5°C of warming is breached is measured as the midpoint of the first 20-year period where global average temperatures are 1.5°C higher than the pre-industrial average.
3
In 2017.
4
In 2011.
5
El Niño events are becoming more intense as a result of climate change.
6
This refers to the amount of heat a greenhouse gas traps relative to carbon dioxide, evaluated over a 100-year period in this example.
7
In 2010.
8
Compared to 2019 values.

What to expect from La Niña

May 14, 2024 by ZCA Team Leave a Comment

Key points:

La Niña is a natural, reoccurring climate phenomenon whereby cold, deep water moves to the ocean surface and cools the central and eastern Pacific Ocean, and warmer water moves to the western Pacific Ocean.
There is an 85% chance of a transition from the current El Niño state to neutral conditions between April and June this year, and a 60% chance of La Niña developing by June to August.
La Niña strongly influences rainfall and weather patterns in various regions of the world and has been responsible for catastrophic droughts and floods, which have severely threatened agricultural production and food security, and caused major economic losses.
La Niña episodes usually last nine to 12 months, but may last for years. The frequency of multi-year La Niña’s has risen in the past several decades, and the longer duration increases risks from weather extremes. The previous La Niña, which lasted from 2020-2023, had devastating consequences for several regions of the world.
Human-caused climate change is at least partly responsible for increases in the variability and frequency of extreme La Niña events.
Some regional trends that can be associated with La Niña include:
- Drier than usual conditions in Ethiopia, Somalia, northwestern and eastern Kenya, northeastern Tanzania, southern and southeastern US, southern Brazil, Uruguay, northern Argentina and southern Bolivia, potentially leading to drought and crop failures.
- Wetter than usual conditions in eastern South Africa, Mozambique, Zimbabwe, Botswana, northern and eastern Australia, southeast Asia, India, northern Brazil, Colombia and Venezuela, with potential for flooding.
- Increased Atlantic hurricane activity, with potentially severe consequences for the southeast coast of North America.

The El Niño-Southern Oscillation cycle

The El Niño-Southern Oscillation (ENSO) cycle – entailing periodic fluctuations in sea surface temperature and atmospheric pressure over the tropical Pacific Ocean – is a natural, reoccurring climate phenomenon that strongly influences rainfall and weather patterns in various regions of the world. La Niña is the cool phase of the ENSO cycle, while El Niño is the warm phase, with a neutral period following these phases.

During La Niña, trade winds – the east-to-west winds that blow along the earth’s equator – intensify, which causes cold, deep water to move to the ocean surface and cool the central and eastern Pacific Ocean, and warmer water to be pushed to the western Pacific. During El Niño, roughly the opposite happens, with weakened trade winds causing central and eastern Pacific ocean water to warm up.

El Niño and La Niña episodes usually last nine to 12 months, but may last for years. While the transitions among various phases occur irregularly, the cycling between the warm and cool phases takes place every two to seven years and brings about predictable changes to ocean temperatures, wind and rainfall patterns.¹ ENSO events are described as Eastern Pacific (EP) or Central Pacific (CP) events depending on where the maximum warming or cooling is located.² Some impacts of EP and CP events differ. For example, CP El Niño events are associated with more severe droughts in Australia than EP events. There has been an increase in the frequency of CP events in the last four decades.

Based on changes in sea surface temperatures and atmospheric conditions in the tropical Pacific, the National Atmospheric and Oceanic Administration is confident that there is an 85% chance of a transition from the current El Niño state to neutral conditions between April and June this year, with a 60% chance of La Niña developing by June to August. Long-range models predict an EP La Niña event this year.

How are La Niña and El Niño predicted?

Scientists use a combination of climate models and observational data, such as sea surface temperature and trade wind strength data from satellites and ocean buoys, to predict the onset of ENSO events several months in advance. Models can forecast La Niña events up to two years’ in advance if the La Niña follows a strong El Niño rather than any other state.³

La Niña and El Niño events are characterised as weak to strong based on the sea surface temperature anomaly – the deviation from the average or baseline – with cooling or warming of 1.5°C or more considered strong. Figure 1 shows the values of the Nino-3.4 index – a measurement of sea surface temperatures in the equatorial Pacific Ocean – from 1950 to 2024. The grey dashed line shows when the sea surface temperature anomaly meets the requirement for an El Niño or La Niña event, generally defined as an anomaly of 0.5°C or more. The red dashed line shows strong La Niña and El Niño events. However, multi-year events that do not exceed this threshold can also have severe consequences, leading to increased risks from droughts, floods and weather extremes due to their long duration – as observed with the 2020-2023 ‘triple-dip’ La Niña. The grey solid line is the global land-ocean temperature index and shows the change in the global surface temperature from 1950 to 2023.

Fig. 1: Sea surface temperature anomalies in the equatorial Pacific and global land-ocean temperature index from 1950-2024

Data source for Niño-3.4 index: US National Weather Service. Data are three-month running averages with a centered baseline. Data source for global land-ocean temperature index: NASA’s Goddard Institute for Space Studies. Values are annual means in reference to a 1951 to 1980 baseline.

By forecasting when El Niño or La Niña will occur, better predictions can be made about possible extreme weather events, helping people to prepare for and mitigate against potential damage associated with these events.

Multi-year La Niña’s are becoming more common

The frequency of multi-year La Niña’s has increased – five of the 10 multi-year La Niña’s over the last 100 years happened in the last 25 years. Multi-year La Niña events have longer-lasting impacts compared to single-year events, such as prolonged above-average rainfall over Australia, Indonesia, tropical South America and southern Africa, and below-average rainfall over the southern United States, Equatorial Africa, India and southeast China.

A study found that multi-year La Niña events are more likely to follow a ‘super El Niño’, which is a particularly strong El Niño – such as the current El Niño, or a CP El Niño. The previous ‘triple-dip’ La Niña event – which lasted from 2020 to 2023 – was a scientific anomaly because it did not match the conventional scientific theories of how prolonged La Nina events develop. Experts reported that it was one of the strongest La Niña events in the past half century. The impacts of this triple-dip La Niña were devastating and included severe flooding in northern Australia, extreme drought in the Horn of Africa – creating one of the worst food security crises in the region for decades, widespread drought in the southwest US, record-breaking hurricane activity, one of the worst droughts on record in South America and heavy rainfall and flooding in Pakistan and northwestern India, with around 15% of the population of Pakistan negatively impacted by the rainfall.⁴

La Niña and the Indian Ocean Dipole

The Indian Ocean Dipole (IOD), which is thought of as the Indian Ocean counterpart of El Niño and La Niña, refers to sea surface temperature anomalies in the Indian Ocean that show a ‘dipole pattern’. When the western Indian Ocean is cooler than usual and the eastern Indian Ocean is warmer than usual, this is referred to as a negative IOD. When the eastern Indian Ocean is cooler and the western Indian Ocean is warmer than usual, this is referred to as a positive IOD. Though independent of La Niña, the IOD is frequently triggered by ENSO events, with negative IOD events typically accompanying La Niña events. Negative IOD events have been linked to extreme rainfall in Indonesia and Australia, and drought in East Africa. Stronger negative IOD events have also been found to make La Niña stronger, and CP La Niña events are also typically linked to stronger IOD events. However, the relationship between ENSO and the IOD is complex due to the diversity and substantial variation in regional feedbacks of ENSO.

Influence of human-caused warming

While ENSO events are natural phenomena, they are occurring against a background state of a warming world, which likely influences their characteristics and impacts. Some changes in ENSO characteristics have been observed over the last few decades, including an increase in the frequency of extreme events and an increase in the variability of events. Similarly, one analysis projects that extremely positive IOD events – linked to drought and wildfires in Indonesia and Australia and flooding in East Africa – will become almost three times more frequent in the 21st century due to climate change. As ENSO is naturally a highly variable phenomenon, determining with certainty whether its characteristics are changing as a result of human-caused climate change is complex – especially as sea surface temperature records have only been available since the 1950s. However, the scientific consensus is that human-caused climate change is at least partly responsible for changes in ENSO variability. Climate change may also be making it less easy to predict extreme El Niño and La Niña events, making it more difficult for people to prepare for potential negative impacts.

Cooler conditions under La Niña do not offset global warming

Though La Niña does cause a decrease of around one tenth of a degree Celcius in the earth’s average surface temperature, this cooling is temporary and is only a fraction of the total average warming of the earth by human-produced greenhouse gases – since industrial times the earth’s average temperature has risen about 1.36°C. To put this number into context, average global temperatures during recent La Niña years have been higher than the average temperatures during El Niño years in past decades, highlighting how much the planet has warmed over the last century (Figure 1). In fact, recent La Niña years have been in the top 10 hottest years ever. Despite the decreased average global temperatures under the upcoming La Niña, 2024 will still likely be one of the top five hottest years on record.

Potential regional impacts of La Niña

As weather patterns around the world are influenced by multiple climate drivers, experts warn against concluding what the impacts of an event will be based on one climate driver alone. However, as La Niña brings about predictable changes to ocean temperatures, wind and rainfall patterns, some general trends can be anticipated (Figure 2).

Fig. 2: Regional impacts of La Niña on rainfall and temperature

Source: National Oceanic and Atmospheric Administration, 2016.

Africa

La Niña is typically associated with drier conditions over December-January in East Africa, including in Ethiopia, Somalia, northwestern and eastern Kenya, and northeastern Tanzania, with implications for crops harvested in February and March and negative effects on livestock. In South Sudan, above-average rainfall could be expected, which might increase crop yields or cause flooding.

La Niña is associated with above-average summer rainfall in eastern South Africa, Mozambique, Zimbabwe and Botswana. In terms of agricultural productivity, South Africa tends to see higher yields of maize, sorghum and wheat, whereas Zimbabwe tends to experience increased maize and soybean yields.

Oceania

In Australia, CP El Niño events tend to bring above-average rainfall to the northern and eastern regions and is linked to severe flooding.

North America

The increase in cold water in the Pacific during La Niña pushes the polar jet stream – a fast air current in the polar region of the Northern Hemisphere – northwards, which tends to cause drier winter and spring conditions in the southern and southeastern US and heavy rains and stormy weather in Alaska, western and central Canada, and the northern US.

Generally, the effects of La Niña in the northern hemisphere are most felt during winter, as it brings colder and wetter winters. There is also an increase in the frequency and strength of Atlantic hurricanes.

The arrival of La Niña around September could benefit maize production in the corn belt of the US but could also reduce water levels in Midwest rivers, with implications for grazing pastures.

Asia

Southeast Asia, including Indonesia, Malaysia and the Philippines, experiences above-average rainfall during CP La Niña events, potentially causing severe flooding. However, rice and palm oil production in the region could be boosted. Due to increased rainfall and cooler conditions, La Niña tends to have a net positive impact on grain yields in China.

In India, La Niña will likely cause above-average monsoon rainfall from July to September and may result in decreased production of pulses, sugarcane and wheat in the Indo-Gangetic Plains, but could increase rice production.

South America

Southern Brazil, Uruguay, northern Argentina and southern Bolivia tend to experience below-average rainfall, potentially leading to drought. Crops such as soybean and maize could be negatively impacted. Northern Brazil, Colombia, Venezuela, and parts of Ecuador and Peru typically experience wetter conditions, with potential for flooding.

1
A cold phase does not always immediately follow a warm phase, and vice versa. In many cases, a cool phase follows from a cool phase, with a varying number of neutral condition months in between.
2
CP events may also be referred to as ENSO ‘Modoki’.
3
There have been significant improvements in models’ ability to forecast ENSO events, but these models still face some challenges – for example, they generally overestimate La Niña and El NIño strength.
4
Climate is complex and influenced by multiple processes. For instance, the extreme rainfall in Pakistan was also attributed to human-caused climate change.

The impacts of El Niño on a warming planet

June 15, 2023 by ZCA Team Leave a Comment

Key points:

El Niño is a natural climate phenomenon, typically lasting 9-12 months, that has been linked to crop failures, more frequent wildfires and concurrent droughts, increased flood risk, disruptions to fisheries, elevated civil conflict and increased disease risk in various regions
Present forecasts predict an 84% chance of at least a moderate El Niño and a ±56% chance of a strong El Niño for 2023-2024
The first year that we see average temperatures exceed 1.5°C could be during El Niño. While this would not mean that the Paris Agreement target has been transgressed, it is a reminder that we are getting closer to this threshold
The frequency and severity of El Niño events increased in the latter part of the 20th century, and climate change is projected to further increase both, as well as making these events more difficult to predict
El Niño involves complex interplay among various atmospheric phenomena, making its impacts difficult to predict. However, it is associated with some general weather trends around the world, including:
- Increased rainfall and flooding risk in East Africa, northern Mexico, the southern US, Peru and Ecuador
- Elevated fire risk in Indonesia, Australia and the Amazon
- Drought conditions in India, southern Africa, the Philippines, Indonesia, the Amazon and Australia
- Warm conditions in Canada and the northern US
Countries and ecosystems are already experiencing impacts from climate change, such as heatwaves, droughts and floods, and El Niño is likely to make these impacts worse.

El Niño

First described by Peruvian fishermen in the late nineteenth century as warm ocean waters around Christmas time that disrupt fishing conditions, El Niño is a natural climate phenomenon in which sea surface temperatures in the tropical Pacific are warmer than average. Under normal (or neutral) atmospheric conditions, trade winds – the east-to-west winds that blow along the earth’s equator – transport warm water from South America to Asia, which is then replaced by cooler water from lower depths. This process, referred to as upwelling, brings nutrients to the surface water, creating fertile fishing grounds. During an El Niño event, the trade winds weaken, causing warm water to accumulate in the Pacific Ocean. By contrast, when the trade winds are strong, the opposite happens and more warm water is transported to Asia – called a La Niña event. These two opposing processes – El Niño and La Niña – make up the El Niño-Southern Oscillation (ENSO) cycle.

In the past, ENSO events were described as Eastern-Pacific (EP) events, because the Eastern Pacific was where the maximum warming was located. However, the last four decades have seen an increase in the frequency of Central-Pacific (CP) events,¹ where the maximum warming is located in the central equatorial Pacific. The characteristics and associated impacts of these two events differ.²

The latest El Niño forecast, issued in June this year by the National Oceanic and Atmospheric Administration, states that El Niño has started and is expected to gradually strengthen during the Northern Hemispheric winter of 2023-2024. There is a ±56% chance of a strong El Niño and an 84% chance of a moderate El Niño. This prediction comes after an unusually long La Niña event lasting three years came to an end earlier this year. This was linked to catastrophic flooding in South-east Asia and Australia, particularly in Pakistan, where flooding displaced around eight million people, as well as the most severe drought in recent history in the Horn of Africa, which has left millions of people displaced and at risk of starvation.

Impacts of El Niño

Though the effects were originally thought to be localised to the coastal regions of Peru and Ecuador, it is now known that the impacts of El Niño, as well as its cooler counterpart La Niña, are global and have been linked to crop failures, increased wildfire frequency, increased flood risk, heightened concurrent drought frequency, disruptions to fisheries, increased civil conflict and higher disease risk in various regions of the world.

El Niño and climate change

The occurrence of extreme El Niño and La Niña events has increased since the 1960s, and climate projections suggest the frequency of extreme ENSO events will increase in the future.³ Some projections suggest a doubling of extreme El Niño events as global temperatures continue to rise.⁴ CP El Niño events are expected to become more frequent with climate change, while EP events are projected to become more extreme.

During the second half of the 20th century, various changes to the behaviour of ENSO were observed, including:

An increase in the occurrence of CP El Niño events
Increased frequency of more extreme El Niño and La Niña events
Increased variability of both CP and EP ENSO events
Changes in the origin of both CP and EP ENSO events since the 1970s from the western Pacific to the central and eastern Pacific.

As ENSO is a naturally highly variable phenomenon, determining whether the characteristics of ENSO events since the 1950s are the result of human-caused global warming, or simply a reflection of this inherent variability, is not straightforward, partly because sea surface temperature records before 1950 are sparse and unreliable.⁵ Estimates using paleoclimate proxy data – which can be found in coral fossils and tree rings, for example – suggest that ENSO variability intensified by around 25% during the latter part of the 20th century compared to pre-industrial times.⁶ A study published earlier this year estimates that human-caused warming has led to approximately one additional CP El Niño event and two additional extreme El Niño events since 1980. Despite the uncertainties, there is a growing consensus that human-caused warming is at least partly responsible for the changes in ENSO variability since the 1960s.

Record high sea temperatures in April this year may also worsen the upcoming El Niño event. We are likely to see record-breaking temperatures with this year’s El Niño, which is occurring against a backdrop of a warming earth – the last eight years were the world’s hottest on record. The hottest of these was in 2016 during one of the strongest El Niño events on record, which saw unparalleled coral heat stress in the world’s oceans resulting in extensive coral bleaching and die-off. ‘Pulse heat stress’ events, such as El Niño, may compound climate change-related stresses on humans and other organisms, with potentially irreversible consequences.⁷

It is more likely than not that global average temperatures will temporarily exceed 1.5°C above pre-industrial levels for the first time in human history between 2023 and 2027.⁸ During an extreme El Niño event, an extra 0.2°C could be added to the average temperature of the earth on top of elevated temperatures due to global warming. The first year that we see average temperatures exceed 1.5°C could be during El Niño. While this would not mean that the Paris Agreement target has been transgressed, it is a reminder that we are getting closer to this threshold.⁹

Countries and ecosystems are already experiencing climate change-induced impacts, such as heatwaves, droughts and floods, and El Niño is likely to make these impacts worse. It has also been suggested that continued global warming is making it increasingly difficult to predict El Niño events.

Regional impacts

Predicting whether an El Niño event will occur, or how intense it will be, is challenging, mainly because predictions need to consider changes in both the Pacific Ocean and the atmosphere. While the characteristics of every El Niño event are different, our understanding of ‘teleconnections’ – whereby a climatic pattern, such as El Niño, is correlated with weather patterns elsewhere in the world – can be used to make predictions about the possible impacts. The figure below shows the typical weather impacts of El Niño across the world.

Source: National Oceanic and Atmospheric Administration

Africa

In East Africa, El Niño conditions tend to result in wetter ‘short rains’ (the second rainy season in November and December), which can cause flooding. There is also a strong link between the Indian Ocean Dipole (IOD) – the Indian Ocean counterpart of El Niño and La Niña, in which there is a difference in sea surface temperatures between the western and eastern Indian Ocean – and El Niño. When there is a positive IOD and EP El Niño, wetter short rains are amplified.

In southern Africa, drier than average conditions are expected under El Niño, resulting in decreased maize yields, while the opposite is anticipated in East Africa. In Kenya, the higher rainfall associated with the 2015-2017 El Niño cycle increased maize production by 17%, while drought conditions in southern Africa during the same period reduced maize yields by up to 50%, caused the death of around 634,000 cattle, and resulted in more than 20 million people needing humanitarian aid. By contrast, wheat yields in South Africa may benefit from El Niño.

During and after El Niño events, cholera incidence has been found to increase threefold in El Niño-sensitive areas in East Africa due to higher rainfall.

India

For India, El Niño tends to weaken the monsoon rains and produce drier conditions, and experts warn that when an El Niño event follows from a La Niña year – as is the case in 2023 – the monsoon rains may be particularly low.¹⁰ An assessment of rainfall trends over 132 years in India shows that severe droughts in the region have always been during El Niño years. Additionally, a CP El Niño event impacts the monsoon more than an EP event, but if an EP event occurs, there is also a higher possibility of a positive IOD occurring, which brings drier conditions to the eastern Indian Ocean (in the region of India) but wetter conditions to the western Indian Ocean (in the region of eastern Africa).

Southeast Asia

In Java, Indonesia, El Niño tends to decrease rainfall. Decreased rainfall during El Niño periods has been linked to increased forest fires in Indonesia and reduced rice yields on Java. where more than 50% of the country’s rice is grown. Fires in Indonesia are more intense and prolonged under an EP El Niño, and southern Kalimantan has experienced more intense fires than southern Sumatra under all El Niño events. However, fires are shorter and less intense during El Niño phases when the IOD is negative or weakly positive.

In the Philippines, El Niño is associated with a decrease in average rainfall and elevated drought conditions, particularly during December to May. The associated water shortages may negatively impact agricultural production in the region – the 2015/2016 El Niño event cost USD 327 million in agricultural production losses. In China, El Niño is linked to higher wintertime air pollution due to southerly winds that encourage the accumulation of particulates.

Europe

El Niño winters are associated with wetter conditions in southern Europe and colder, drier conditions in northern Europe.

Australia

In Australia, El Niño is expected to bring higher temperatures and fire risk, and lower rainfall. Australia is warming faster than some other regions on earth – being 1.4°C warmer than it was during pre-industrial times – potentially making it particularly vulnerable to the effects of El Niño.

North America

In the Northern US and Canada, El Niño is associated with warmer conditions, whereas in the southern US and northern Mexico, wetter, cooler conditions with increased flooding risk are expected. El Niño weakens Atlantic hurricane activity but increases Pacific hurricane activity.

El Niño may reduce wheat yields in the US as well as maize yields in the southeastern US, while soybean yields may increase.

South America

El Niño typically brings heavier rains and flooding risk to Ecuador, Peru and Uruguay, A CP El Niño brings drier conditions to the tropical Andes and northern South America, but wetter conditions to southeastern South America and the Peruvian Amazon. An EP El Niño is linked to higher rainfall in Ecuador and Peru and dry conditions in northeastern Brazil, the Amazon Basin and the Andean Plateau. Specifically, an EP El Niño is associated with reduced rainfall in northern, eastern and western Amazonia, with significant impacts on water and carbon cycling – whereby carbon atoms are cycled between the atmosphere, organisms and minerals on earth. During EP El Niño events, lower rainfall occurs across all seasons in the Amazon, turning the Amazon into a net carbon source as trees dry out and slow their growth. During CP El Niño events, reduced rainfall is only observed during the summer wet season. Increased drought may drive forest fires and biome transformation in the Amazon. Warmer, drier conditions in Colombia during El Niño have been linked to outbreaks of dengue fever and malaria.

El Niño may positively affect maize production in Argentina and Brazil, soybean and rice production in Brazil, and wheat production in Argentina due to cooler and wetter conditions. In Mexico, El Niño could reduce maize and wheat output.

1
CP El Niño events are also referred to as “El Niño Modoki” and “warm pool El Niño”.
2
EP ENSO has stronger El Niño events compared to La Niña events, whereas CP ENSO has stronger La Niña events compared to El Niño events.
3
The IPCC AR6 WGI report states that “a robust increase in ENSO rainfall amplitude [used for defining extreme El Niños and La Niñas] is found particularly in SSP2‑4.5, SSP3‑7.0, and SSP5‑8.5… The changes in ENSO rainfall amplitude in the long-term future (2081–2100) relative to the recent past (1995–2014) are statistically significant at the 95% confidence [level]”.While climate models do not show consensus regarding changes in ENSO sea surface temperature variability, models that simulate extreme ENSO events do show large agreement.
4
The future period in the study included projections until 2090.
5
In the IPCC AR6 WGI report it states that “there is medium confidence that both ENSO amplitude and the frequency of high-magnitude events since 1950 are higher than over the period from 1850 and possibly as far back as 1400”.
6
Paleo-reconstructions typically have large uncertainty.
7
For instance, the 1982/1983 El Niño event led to the possible extinction of a coral species in Panama.
8
A 66% chance of exceeding 1.5°C for one year, according to the World Meteorological Organisation’s Global Annual to Decade Climate Update. It is unlikely (33% chance) that the 5-year average temperature will remain above 1.5°C between 2023 and 2027.
9
Breaching the Paris Agreement target of 1.5°C of warming since pre-industrial times – a threshold seen as important for limiting the impacts of climate change on people and nature – would require several decades of average temperatures above 1.5°C.
10
Though this is dependent on various factors, such as lower Eurasian snow cover, which creates warmer conditions on the subcontinent, thereby bringing more rain to India.

An introduction to loss and damage

November 11, 2022 by ZCA Team Leave a Comment

Key points:

Loss and damage refers to those inevitable impacts of climate change that have not been avoided through mitigation and adaptation, or that cannot be avoided because it is impossible to do so
Despite being responsible for emitting the majority of greenhouse gas emissions since the Industrial Revolution, rich nations have fiercely hindered negotiations on loss and damage financing and are reluctant to make any commitments
A dedicated loss and damage financing facility is high on the agenda for the Global South at COP 27 and would help ensure that funds are collected and distributed equitably and to the most vulnerable communities
Attribution science is important for linking human-caused emissions to increases in the likelihood or magnitude of climate disasters and has a key role to play in assigning culpability for climate impacts
Climate justice movements argue that loss and damage is a restorative justice issue. It is imperative, they say, that the Global North accepts responsibility for loss and damage and actively works to redress and repair the social injustices and direct impacts of climate change.

What is loss and damage?

Loss and damage refers to those inevitable impacts of climate change experienced by the Global South that have not been avoided through mitigation and adaptation due to socio-political or economic constraints, or that cannot be avoided because it is impossible to do so. It may encompass a wide range of circumstances, including:

Extreme weather or rapid-onset events, such as storms, cyclones, heatwaves and floods
Slow-onset events, such as drought, desertification, increasing temperature, land degradation and sea level rise
Non-economic impacts, such as the loss of cultural heritage, animals, plants and tradition
Economic impacts, such as loss of lives, livelihoods, homes, agriculture and territory.

Some of these risks can be addressed through adaptation measures. If the measure is not yet available but could become available in the future, the risk is considered to be a ‘soft adaptation limit’. An example of this might be the development and implementation of an early warning system for floods in a region that is becoming increasingly flood prone. However, some risks have a ‘hard adaptation limit’, meaning that the available technologies and actions for averting this risk are not feasible. An example of this might be when an island becomes uninhabitable because of sea-level rise.

It is helpful to think about climate risks as being situated along a continuum (see Fig. 1, adapted from here) of avoided risks (risks that have or will be avoided through mitigation), unavoided risks (risks that cannot presently be avoided or reduced due to socio-economic constraints) and unavoidable risks (hard adaptation limits). Loss and damage is centered around unavoided and, particularly, unavoidable risks.

While the debate around what loss and damage is, and who should compensate for it, has gained a lot of coverage recently, it has actually been a point of discussion for several decades. The first mention of loss and damage in international fora was in 1991 when the Alliance of Small Island States (AOSIS) proposed an international insurance pool that would compensate low-lying islands for loss and damage associated with sea-level rise. The first time loss and damage was mentioned in UNFCCC documents was in the 2007 Bali Action Plan. This initiated formal UNFCCC activities in the 2010 Cancun Adaptation Framework for advancing technical work on loss and damage.

Historical responsibility and polluters must pay

Loss and damage is a contentious and highly politicised topic. This is because while rich nations are responsible for most of the greenhouse gases in our atmosphere emitted since the Industrial Revolution, the warming caused by these emissions is disproportionately impacting less developed countries that have contributed the least to global warming. For example, Africa is responsible for just 3% of all carbon dioxide emissions over the last few centuries but is the most vulnerable continent to the impacts of climate change. By 2030, vulnerable nations may face USD 290-580 billion in annual loss and damage, and this figure could increase to USD 1-1.8 trillion by 2150. By 2050, up to 216 million people may be forced to leave their homes due to climate impacts. UN Secretary General Antonio Guterres describes climate justice as “a case study in moral and economic justice” and believes “polluters must pay” because “vulnerable countries need meaningful action”.

Communities across the Global South make up the vast majority of the 3.6 billion people considered ‘extremely vulnerable’ to climate impacts by the UN. Climate justice movements argue that the major emitters in the Global North bear the primary responsibility and a financial obligation for addressing loss and damage, thereby owing huge ecological debt to the vulnerable nations of the south. Emissions from the richest countries caused an estimated USD 2.3 trillion in damages between 1961 and 2000, and it is estimated that the total amount of climate debt could be as high as USD 34 trillion. This debt reflects the financial burden that the industrialised economies of the Global North have imposed on the Global South to mitigate and adapt to climate impacts.

This financial burden extends to the devastation caused by colonial extraction. For the first time since its inception, the IPCC mentioned the word ‘colonialism’ in its sixth assessment report in 2022. Extractive industries established by colonial powers helped pave the way for the establishment of the modern world order characterised by global social and economic inequality. These global power imbalances create vulnerability to loss and damage, and so loss and damage is deeply linked to colonial histories.

Much of the climate justice debate has focused on who is responsible for the impact of climate change and how the burdens of climate change can be distributed fairly and equitably. In every climate disaster, the poorest are the most vulnerable and hardest hit. However, Global North countries have fiercely hindered progress on loss and damage financing negotiations and are reluctant to commit to loss and damage funding due to concerns around legal liability, fearing that they may become locked into open-ended litigation and compensation for climate-induced disasters. Getting polluters to compensate for loss and damage would be a significant step towards redressing global climate injustice.

Attribution has greatly shaped the discussion around loss and damage, and advances in attribution science can show how human-caused emissions have increased the likelihood or magnitude of both rapid and slow-onset events. Attribution science has an important role to play in helping to understand loss and damages, in highlighting the different drivers of climate change and in helping to bring more court cases against polluters.

A study published in July this year attributed greenhouse gas emissions from high-emitting countries to substantial economic losses in low-income, tropical parts of the world and economic gains in high-income, midlatitude regions. This is the first study to directly quantify the culpability of nations for historical temperature-driven income changes in other nations. Studies like these can provide critical insight into climate liability and national accountability for climate policy.

An example of where attribution science has been used to bring a case against a polluter is a study showing that the melting of the Palcaraju glacier in the Peruvian Andes – which presents a flooding hazard to the city below it – is entirely attributable to rising temperatures. In this case, a Peruvian farmer is holding the German utility company RWE accountable for the role of its emissions in the melting of the glacier, proposing that the company should contribute to the construction of flood defenses. Its contribution would be based on RWE’s share of global emissions, which has been estimated at 0.47%. If successful, this could be a game-changer for getting polluters to pay for climate damages.

However, developing nations argue that polluters should also be held responsible for losses and damages that cannot be quantified or recovered at any cost – framed as symbolic reparations. There is no amount of money that can bring back lost territory due to sea-level rise or the cultural heritage, animals and plants, human lives and ancestral lands that could be lost due to climate change. For these impacts, reparations may take the form of official apologies and recognition, the building of museums and memorials, truth and reconciliation conferences and other means of helping to maintain a sense of cultural identity where this has been lost due to climate change.

Major milestones for loss and damage in policy negotiations

Establishment of the Warsaw International Mechanism for Loss and Damage (WIM) at COP 19 in 2013
- The WIM aims to ‘address the impacts of loss and damage associated with the impacts of climate change, including extreme events and slow-onset events, in developing countries that are particularly vulnerable to the effects of climate change”
- The WIM Executive Committee (ExCom) was also formed at COP 19 to guide the implementation and functions of WIM through negotiated workplans, with three objectives – knowledge generation, coordination and support to address loss and damage. The first two-year workplan was approved at COP 20 in 2014

At COP 21 in 2015, the Paris Agreement was adopted. Article 8 established that parties of the agreement “recognise the importance of averting, minimising and addressing the loss and damage associated with the adverse effects of climate change”. This was the first time that loss and damage was formally acknowledged as an issue separate from adaptation.
The first review of WIM took place at COP 22 in 2016, where the framework for the five-year rolling workplan of ExCom was approved
At COP 24 in 2018, the recommendations made by ExCom on integrated approaches to avert, minimise and address displacement related to climate change were accepted
The second review of WIM took place at COP 25 in 2019, which led to the establishment of the Santiago Network, which aims to catalyse the technical assistance of relevant organisations, bodies, networks and experts
At COP 26 in 2021, the functions of the Santiago Network were agreed upon. The Group of 77 + China (a negotiating bloc for developing countries) proposed that a dedicated loss and damage financing facility (LDFF) be established, but this was rejected at the talks.
- The Glasgow Dialogue was then established as an alternative to the LDFF for facilitating discussion among Parties, relevant organisations and stakeholders regarding funding activities to avert, minimise and address loss and damage
- The dialogue will take place during annual subsidiary meetings until 2024

In June 2022, the 1st Glasgow Dialogue took place at Bonn, where the proposal for loss and damage to be an agenda item for COP 27 was rejected, largely because the EU and US feared that they would become liable for billions of dollars in damages
Loss and damage was then accepted as a draft agenda item for COP 27 after the G77 + China wrote to the UNFCCC Secretariat in June this year. “Matters relating to funding arrangements responding to loss and damage associated with the adverse effects of climate change, including a focus on addressing loss and damage” is now an official agenda item for COP 27 and for the CMA (which mandates the work under the Paris Agreement)
In September, more than 400 organisations signed a letter initiated by the Climate Action Network (CAN) to make the financing of loss and damage an agenda item for COP 27. The G77 + China will continue their call for a dedicated LDFF at COP this year.

A timeline of milestones can be found here.

What can we expect at COP 27?

A submission by the G77 and China on 13 June 2022 to the UNFCCC Secretariat to make “matters relating to funding arrangements for addressing loss and damage” a provisional agenda item for COP27 and CMA4 this year was accepted. The Presidency of COP 26 and the incoming Presidency of COP 27 convened informal multilateral consultations on loss and damage with Group Chairs and Heads of Delegations in July 2022. In these discussions it was acknowledged that:

Operationalising the Santiago Network at COP 27 is necessary to fulfil its purpose of providing relevant technical assistance to developing countries, and that it would be important to establish predictable and adequate funding for the network
A greater need for funding arrangements for loss and damage is also necessary, as disappointment was expressed by Parties who felt that a way forward for the funding of the issues raised in the first Glasgow Dialogue had not been presented
From a loss and damage perspective, a successful COP 27 would “mean a concrete outcome on the Glasgow Dialogue, which would mean the establishment of funding arrangements or a funding facility under the COP and the CMA to address loss and damage with transparent, predictable resources, which would be separate from adaptation finance, and an agreement for it to become a standing COP and CMA agenda item”.

The Climate Vulnerable Forum (CVF) – a partnership of developing countries that are highly vulnerable to climate change – has also played a key role in increasing the focus on loss and damage, including calling for COP 27 to mandate the IPCC to write a special report on the subject. At the closing of the Glasgow Dialogue on Loss and Damage, the CVF stated that “Loss and damage is an emergency agenda, indeed it should be considered as a third pillar under the convention in addition to mitigation and adaptation, its funding shall be considered high in our agenda”.

Criticisms of the UNFCCC policy and process

While Article 8 on loss and damage was fundamental in anchoring both in the Paris Agreement, it is compromised by the inclusion of a provision by developed countries stating that it does not “involve or provide a basis for any liability or compensation” (paragraph 51 of Decision 1/CP.21). This suggests support for loss and damage will be on a cooperative basis. Unfortunately, there has been little cooperation between developed countries. The current mechanisms available under the UNFCCC are focused on averting loss and damage through mitigation and adaptation, and there are no means available to help people recover from the impacts of climate change that go beyond their ability to adapt.

Major criticisms of the Warsaw International Mechanism for Loss and Damage executive committee established in 2013 workplans are that it is characterised by broad goals that are ambiguous regarding start lines and deadlines. They are also lacking in strong commitments. Many believe the WIM has focused too much on improving understanding and strengthening the coordination of loss and damage rather than facilitating action and addressing loss and damage events that have occurred.

Loss and damage: The case of Pakistan

Record torrential downpours in Pakistan earlier this year affected 33 million people, with more than 1,730 losing their lives. The economic losses are estimated at USD 30-35 billion. Guterres exclaimed on a recent visit to Pakistan that: “Loss and damage from the climate crisis… is happening now, all around us… I urge governments to address this issue at COP 27 with the seriousness it deserves”.

It is thought that the rainfall in Pakistan was at least 50% more intense because of global warming. The representative of Pakistan to the UN and chairman of the G77, Munir Akram, emphasised that while Pakistan is one of the lowest emitters of carbon, it is the fifth-largest victim of climate change. He said that at COP 27, developing countries “will be pressing for the rights of developing countries to equitable treatment, or in terms of support for adaptation as well as compensation for loss and damage”. Pakistan Climate Change Minister Sherry Rehma has also been very vocal on the subject, stating that: “There is so much loss and damage with so little reparations to countries that contributed so little to the world’s carbon footprint that obviously the bargain made between the Global North and global south is not working. We need to be pressing very hard for a reset of the targets”.On a similar note, a recent report suggests with high certainty that the Horn of Africa will be entering its fifth consecutive year of drought. One article suggests that this report has sparked renewed interest in calls for loss and damage compensation for Africa.

Activist and civil society engagement on loss and damage

The outcry in favour of recognising loss and damage, and funding restitution for it, has been growing considerably. Increasingly, climate movements and developing nations have framed the funding of loss and damage as a means of reparation. In general, reparations are founded on equity and justice ideals and endeavour to rectify significant damage caused to vulnerable communities, including the use of financial and non-financial resources.

Climate justice movements argue that loss and damage must reside in a matter of restorative justice. This implies acceptance of responsibility by the Global North, followed by measures that seek to address and repair social injustices and the widespread direct impacts of climate change. In addition to financial reparations, demands in the form of technology transfer, the elimination of restrictive immigration policies, and guarantees of non-repetition have been raised by the People’s Agreement of Cochabamba at the World People’s Conference on Climate Change to collectively form a programme for restorative justice. However, these demands have yielded little results, which is why activists and developing nations hope to emerge from COP27 with a concrete package of measures and a sustainable system of long-term loss financing and damage restitution.

Several climate strikes organised by movements like Fridays For Future (FFF) have taken to the streets worldwide in the months prior to COP 27 demanding effective and sweeping climate justice and reparations. Activist groups led by the most impacted frontline communities have also long been working on the matter.

International NGOs active in the UNFCCC, such as Greenpeace, Earthjustice and the Climate Justice Program, have promoted the use of litigation for addressing loss and damage, and Germanwatch has specifically advocated for litigation around loss and damage.

A dedicated financing facility for loss and damage

The financing of loss and damage was a key sticking point in negotiations at COP 26 last year. The establishment of a dedicated loss and damage financing facility is supported by many climate-vulnerable and developing countries. But many developed countries feel the financing of loss and damage could be drawn from existing financial institutions. However, these institutions do not provide support for non-economic loss and damage or slow-onset events such as the loss of crop production due to sea level rise, desertification or salinisation. Moreover, loss and damage funding needs to be available at short notice, such as in the event of damage from an extreme weather event, and this is not supported by currently-available adaptation funds. Regarding other financing options, humanitarian aid is unreliable, short-lived and does not deal with slow-onset events, and development finance often prioritises donor preferences.

The V20 Multi-Donor Fund, the Global Environment Facility (GEF) and the Climate Vulnerable Forum (CVF) have worked on a pilot loss and damage fund, with the aim of demonstrating that loss and damage financing is possible at scale. The facility is expected to be launched at COP 27.

A new report by the Stockholm Environment Institute (SEI) on operationalising finance for loss and damage found that climate finance is largely inaccessible for recipient countries due to stringent proposal requirements and long lags in delivery. In addition, loan-based finance often increases the debt burden of countries and doesn’t reach the most vulnerable communities. The institute recommends that a global loss and damage financing facility should:

Prioritise the delivery of funding directly to communities and marginalised groups
Prioritise small grants and unconditional cash transfers to reach vulnerable communities, and avoid loans that increase debt burdens
Ensure that recipients are included at all stages of decision-making
Create accountability mechanisms that empower recipient communities
Agree on a phased approach at COP 27 of establishing a dedicated loss and damage facility in the medium term and mobilising finance through existing mechanisms in the future.

Exploring a comprehensive loss and damage facility for African countries

November 9, 2022 by ZCA Team Leave a Comment

Key points:

Africa is responsible for just 3% of all carbon dioxide emissions since the Industrial Revolution but is the most vulnerable continent to the impacts of climate change
These impacts will increasingly exacerbate poverty and inequalities and disrupt livelihoods
Comprehensive loss and damage facilities could be established at the national level in order to address country-specific needs
These would function at multiple levels to cover unavoided and unavoidable, economic and non-economic losses and damages, and would encompass risk and curative (i.e. compensatory) finance mechanisms, with funding obtained through multiple avenues
The finance sources could include philanthropy and solidarity funds, multilateral sources such as grants, loans and multi-donor trust funds, and other finance sources such as carbon levies and taxes, collected and distributed through a formal financing mechanism that is yet to be established.

The politics of loss and damage

Loss and damage – which refers to the negative impacts of climate change that may or may not be reduced by adaptation – is a contentious and highly politicised topic. This is because while developed nations are responsible for most of the greenhouse gases emitted since the Industrial Revolution, the warming caused by them is disproportionately impacting less developed countries that have contributed the least to global warming. For example, Africa is responsible for just 3% of all carbon dioxide emissions over the last few centuries but is the most vulnerable continent to the impacts of climate change.

Though the concept of loss and damage is formally recognised by the UN Framework Convention on Climate Change (UNFCCC) and has always been discussed at COPs, no provision has been made for the financing of loss and damage. Indeed it was a key sticking point in last year’s COP negotiations. Wealthy nations are reluctant to commit to loss and damage funding due to concerns around legal liability, fearing they may become locked into open-ended litigation and compensation for climate-induced disasters. A proposal for a dedicated financing facility for loss and damage at COP last year by the negotiating bloc of the Group of 77 + China – which was supported by many climate-vulnerable and developing countries and civil organisations – was rejected by the US and EU. A formal mechanism for collecting and distributing funds for loss and damage – whether by establishing a dedicated financing facility or placing it in an existing fund (such as the Adaptation Fund) – will be high on the agenda for the Global South at this year’s COP 27 meeting.

Avoidable, unavoided and unavoidable risks

Loss and damage may encompass a wide range of circumstances, including:

Extreme weather or rapid-onset events, such as storms, cyclones, heatwaves and floods
Slow-onset events, such as drought, desertification, increasing temperature, land degradation, sea level rise and salinisation (an increase in concentrations of salt in soil)
Non-economic impacts, such as the loss of cultural heritage, native animals and plants and tradition
Economic impacts, such as loss of lives, livelihoods, homes, agriculture and territory.

These impacts will further exacerbate poverty and inequalities and disrupt livelihoods, and increasingly so as temperatures rise. Some of these risks can be addressed through adaptation measures. If the measure is not available yet but could become available in the future, the risk is considered to be a ‘soft adaptation limit’. An example of this might be the development and implementation of an early warning system for floods in a region that is becoming increasingly flood prone. However, some risks have a ‘hard adaptation limit’, meaning that the available technologies and actions for averting this risk are not feasible. An example of this might be when an island becomes uninhabitable because of sea-level rise.

When considering risk financing mechanisms for loss and damage, it is helpful to think about risks as being situated along a continuum (see Fig. 1, adapted from here) of avoided risks (risks that have or will be avoided through mitigation), unavoided risks (risks that cannot presently be avoided or reduced due to socio-economic constraints) and unavoidable risks (hard adaptation limits). Loss and damage is centered around unavoided and, particularly, unavoidable risks.

The different finance mechanisms available

Risk finance

A comprehensive climate risk management strategy to avert, minimise and compensate for unavoided and unavoidable loss and damage would include ambitious mitigation, adaptation and disaster risk-reduction action. Various risk financing mechanisms based on risk pooling (spreading risk by sharing it across different lenders/insurers) and transfer exist that could be used to address loss and damage:

Catastrophe/disaster risk insurance
- Aimed at developing tailored financing strategies for improving financial resilience to natural hazards
- One example is the National Agricultural Insurance Scheme (NAIS) in India, which aims to mitigate risks related to crop and livestock loss from climate events. The NAIS is funded by a state-owned insurer and receives technical support from the World Bank
- Microinsurance can provide financial support to low-income households following disasters. One example is Acre Africa, a World Bank initiative offering innovative and tailored microinsurance products to help small-scale farmers mitigate against crop failure from adverse weather

National social protection schemes or social funds
- These consist of a wide range of policies and interventions aimed at reducing poverty, inequality and vulnerability, including social protection programmes, contributory social insurance and social health protection
- An example is South Africa’s Working for Water programme, which employs people in public sector projects to conserve water and ecosystems, thereby improving climate change adaptation and disaster risk reduction. The programme is funded by both government and private entities

Contingency finance
- Governments set aside public funds or obtain loans from multilateral financing institutions in order to respond rapidly in the aftermath of a disaster
- If a loan is secured from a development bank, governments will only incur a cost in the event that funds need to be drawn from the loan

Catastrophe-linked bonds
- Risks are transferred from developing countries to the capital markets – financial markets where buyers and sellers trade bonds and other financial assets – in the event of a catastrophe, thereby filling in the financing gap for immediate post-disaster relief from extreme events
- For example, the World Bank issued a catastrophe-linked bond (listed on the Singapore Stock Exchange) to provide support for losses of up to USD 150 million from tropical cyclones in the Philippines

Climate-themed and green bonds
- These are instruments that finance green or climate-themed projects and provide investors with regular or fixed income. Investors hedge against climate risks and receive returns on their investments
- The International Finance Corporation (IFC) – a World Bank institution – has contributed substantially by issuing and investing in green bonds
- For example, in 2021, the IFC invested USD 100 million in Egypt’s first private sector green bond to help finance sustainable projects and the transition to a greener economy

Forecast-based financing
- These are funds that are released for pre-defined actions based on scientific forecasts and risk analysis
- For instance, in Bangladesh, emergency kits are distributed prior to a cyclone.

These risk financing mechanisms are mostly appropriate for avoidable/unavoided loss and damage. However, it is not possible to prevent or minimise loss and damage that go beyond hard adaptation limits (unavoidable loss and damage) – such as many impacts from slow-onset events. For risks that cannot be addressed using these risk pooling and transfer mechanisms, curative finance may be needed:

Curative finance

Loss and damage funds
- These are trust funds that facilitate access to international finance and raise local money for climate change mitigation, adaptation, risk management and compensation
- A significant amount of donor support is required for these funds, which may be sourced from various entities (see the box on ‘where the money comes from’ below)
- An example is Bangladesh’s National Mechanism for Loss and Damage, which is financed through multi-donor trust funds and the national budget

Impact investment funds
- Environmental and climate projects are financed by private and public funds, providing investors with returns on their investment
- An example is Livelihood Carbon Funds, which invest in projects such as mangrove restoration in Africa

Trust funds
- Funds are especially established to deal with a specific need, such as relocation due to climate change
- For example, the Fiji Climate Relocation and Displaced Peoples Trust Fund for Communities and Infrastructure that was developed to respond to displacement due to sea-level rise
- Funding is obtained from a climate and adaptation levy (whereby certain services, incomes and items are taxed) and, potentially, bilateral and multilateral funding.

The finance sources discussed in the box below could be used for both risk finance and curative finance mechanisms.

Where might the money come from?

Philanthropic and solidarity funds

Philanthropic funds
- At COP 26, several philanthropic climate funders, including the European Climate Foundation, Open Society Foundations, and Hewlett Foundation, committed an initial USD 3 million in loss and damage finance as ‘start-up assistance’

Solidarity funds. Here are examples of what solidarity funds could look like:
- The European Union Solidarity Fund (EUSF) – financial contributions are made by EU member states and are administered by a flexible governing mechanism
- Unitaid – finance is obtained through national aeroplane levies, voluntary contributions by countries and philanthropy

Government pledges
- At COP 26, Scotland and Wallonia committed USD 2.5 million and USD 1 million respectively to financing loss and damage
- Denmark committed USD 13 million to loss and damage financing this year.

Multilateral sources

Within the UNFCCC, the Green Climate Fund (GCF) is the only source providing adaptation and loss and damage financing. Approximately 24% of GCF-approved projects refer to loss and damage
Global Facility for Disaster Reduction and Recovery (GFDRR), which is a grant-funding mechanism
Global Risk Financing Facility (GRiF), which is a multi-donor trust fund that provides grants
Multilateral development banks, which could provide assistance in the form of grants (need not be paid back) and loans (need to be paid back)
The multi-donor trust fund of the Climate Vulnerable Forum and the Vulnerable Twenty Group
The World Bank’s International Development Association (IDA), which provides finance via concessional loans and grants and policy advice to developing countries
Official development assistance (ODA) – between 2010 and 2019, 11% (USD 133 billion) of international aid was disaster-related, suggesting that ODA could be an important source of loss and damage finance.

Innovative finance sources

Luxury carbon tax or wealth tax
- Levies and taxes could be added to luxury or high-emissions intensity products or activities, such as space tourism, buying luxury yachts and sports cars and using private jets

Financial transaction tax
- A small levy could be placed on the buying and selling of financial assets, which could provide up to USD 16 billion in revenue.

International airline passenger levy
- A modest fee on international aeroplane tickets could be paid directly into a loss and damage fund

Bunker fuels levy
- The emissions and fuels of cargo transportation by ship and aeroplane could be taxed. The International Monetary Fund (IMF) estimated that a tax of USD 30 per tonne of carbon emitted by aeroplanes and ships (advanced economies only) would have raised USD 25 billion in 2014

Fossil fuel majors carbon levy
- The Carbon Majors report in 2013 found that 63% of emissions in the atmosphere are from coal, gas, oil and cement from only 90 companies
- A global fossil fuel levy could be imposed on these companies and directed into a loss and damage fund that could be supplemented by a one-off fee from each company based on its historical emissions
- For instance, the prime minister of Barbados has proposed a 1% tax on sales revenues for fossil fuels, which could raise USD 70 billion each year

Global carbon tax
- A global system of carbon pricing could help fund loss and damage either through taxation or auction revenues generated from trading schemes, such as the EU Emissions Trading System.

What would a comprehensive loss and damage facility look like for African countries?

Comprehensive loss and damage facilities could be established at the national level in order to address country-specific needs. The facility would need to function at multiple levels to cover unavoided, unavoidable, economic and non-economic losses and damages and would encompass the risk finance and curative finance mechanisms discussed above, with funding obtained through multiple avenues. It would also require close cooperation and coordination among different levels of government, the multilateral system and various sectors across society. A potential loss and damage facility could be broken down into four main components:

Knowledge and capacity development
Resilience building
Funding collection and allocation
Compensation for, and recognition of, unavoidable loss and damage.

Knowledge and capacity development

These are knowledge and technology-sharing measures for averting and minimising loss and damage impacts:

Establish centralised and reliable climate change databases

The database should include high-quality meteorological data, climate projections and warnings and archives of climate events
National governments and research institutes need access to sophisticated technologies such as numerical flood monitoring and flood mapping infrastructure, and improved data collection tools and capacity in order to better understand trends and respond appropriately
These tools would be fundamental for developing early-warning systems for floods, droughts, fires and other climate hazards
This information is also important for climate change attribution.

Build collaborative and inter and trans-disciplinary research

Encourage skills sharing between research institutes and universities in developing and developed nations to ensure that local entities have access to the latest and most sophisticated tools for monitoring events
For example, the University of KwaZulu-Natal in South Africa is working with the Dutch research institute Deltares to develop an early warning system for floods
Increase university funding for research on loss and damage and climate change from international donors and public funding sources.

Strengthen technical capacity building for local governments

Provide local governments with the tools, expertise and capacity to effectively coordinate preparations for and responses to climate disasters
For instance, the Council for Industrial and Scientific Research (CSIR) in South Africa has developed a state-of-the-art online risk profiling and adaptation tool, called the Green Book, for assisting municipalities in assessing risks and vulnerabilities to climate change. The tool is co-funded by the Canadian International Development Research Centre and was produced together with South Africa’s National Disaster Management Centre.

Resilience building

These are physical measures for averting and minimising loss and damage impacts that prioritise climate-resilient interventions:

Investment into projects that promote climate resilience

For example, Access Bank in Nigeria issued a certified green bond that will mostly go towards building coastal flood defenses to protect against sea-level rise.

Construction of physical climate barriers and adaptation measures

For example, the construction of sea walls along Tanzania’s coastline, funded by the US Adaptation Fund and the Global Environment Facility’s Least Developed Countries Fund
Through the Adaptation Fund Climate Innovative Accelerator, grants are being administered for innovative adaptation technologies. An example is Slamdam, an inexpensive technology for protecting people from flooding that is being piloted in Burundi.

Preventative building measures, such as retrofitting houses to improve resilienceFor example, low-cost homes in South Africa were retrofitted with ceiling insulation through a local government project financed by South Africa’s Green Fund, which has a portfolio of investment projects and is managed by the Development Bank of Southern Africa.

Case study 1: Extreme precipitation in Durban, South Africa

Earlier this year, extremely intense rainfall (> 450 mm in 48 hours) led to flash floods and landslides in Durban in South Africa, killing more than 450 people, destroying 4,000 houses, displacing around 40,000 people and causing ZAR 1.7 billion in damages. This event is considered one of the worst natural catastrophes in South African history in terms of economic and human life loss and was made twice as likely due to climate change.

The floods disproportionately affected marginalised communities and the impacts were worsened by pre-existing structural vulnerabilities – a legacy, in part, of centuries of colonialism and apartheid, further exacerbated by current exploitative international relationships and global power imbalances.

South Africa was ill-prepared to respond to the event:

There is no reliable disaster risk database
Local, provincial and national governments have not been proactive in planning and building resilience, which may be due to a lack of coordination, finance, capacity or expertise
Early-warning systems and flood mitigation measures are inadequate, and so no rapid-response system is available.

Other factors compounded the risks from this event, including uncontrolled urbanisation and a lack of land-use zoning enforcement (e.g. stopping people from building below the flood line). In addition, poor education in many communities means that people may not fully understand the danger posed by such an event and may be reluctant to move when asked to. The region is also reeling from the negative economic impacts of the Covid-19 pandemic and socio-economic unrest.

Who paid for the impacts?

Contingency finance from South Africa’s National Disaster Management Centre
Multipurpose cash grants for victims from UNICEF, funded by EU humanitarian aid funding, provided immediate relief
Flood relief funds from nonprofits, financed by donors
The Industrial Development Corporation, owned by the South African government, which is funded through loan and equity investments from commercial banks, development finance institutions and other lenders
Insurance schemes self-funded by individuals and businesses
Provincial government entities, such as the Coega Development Corporation.

In addition to this, a comprehensive loss and damage facility for averting, minimising and compensating for this disaster might cover the following:

Developing an advanced early-warning and rapid-response system
- Acquire funding from international sources, including research grants, to facilitate research
- Facilitate skills and expertise sharing with international experts
Relocating at-risk communities to suitable land above the flood line
- Financed through trust funds set up for relocation
Protecting at-risk infrastructure through flood control mechanisms
- This could be funded through green bonds or impact investment funds.
Providing facilities in anticipation of events
- Allocate forecast-based financing for distribution of health packs or mobile health facilities
Uplifting local communities through resilience measures
- Invest in national social protection schemes and preventative measures (i.e. retrofitting houses to make them flood or rain proof)
- Invest in projects that empower local government to educate and communicate with communities on flood impacts.

Fund collection and allocation

These are approaches for maximising fund collection and allocation for loss and damage impacts:

Diversify funding sources

Design funding options that are not currently in place, such as from innovative sources
Encourage funding to be based on grants and concessional loans (i.e. loans that offer more favourable terms than market-based loans).

Streamline funding acquisition

Maximise overall loss and damage financing through comprehensive risk management frameworks that include a range of funding sources, rather than relying on ex-post (after the event) aid, which is unreliable and difficult to monitor
Diversify social protection measures and the financing thereof
Improve government capacity to undertake international negotiations on loss and damage financing.

Establish trust funds

Multilateral development banks and national development banks have great potential to address loss and damage through trust funds
Trust funds geared towards country-specific needs should be established, such as the Fiji Climate Relocation and Displaced Peoples Trust Fund for Communities and Infrastructure, which was developed to respond to displacement due to sea-level rise.

Develop a dedicated loss and damage financing mechanism

A dedicated financing facility should be established to track and prioritise which aspects of loss and damage need funding
Ensure that the funds are reaching the most vulnerable.

Case study 2: Tropical cyclone Ana in Mozambique

Mozambique experienced extreme rainfall from tropical cyclone Ana this year, displacing 180,869 people, destroying 12,000 houses, damaging 26 health centres, 2,275 km of road and 765 schools, and flooding 37,930 hectares of crops, severely impacting food security. Climate change increased the likelihood and intensity of the rainfall associated with these cyclones, and these events are projected to become increasingly severe with climate change. Mozambique has contributed 0.01% of global carbon dioxide emissions since the Industrial Revolution.

Sixty percent of the population of Mozambique lives along the coastline and is vulnerable to tropical storms. Mozambique ranks 9th out of 191 countries globally in terms of high vulnerability to climate impacts, exposure to risk and lack of coping capacity. Recent military insurgence in some parts of the country, rooted in unemployment, underdevelopment, poor governance and poverty, has led to the death of around 4,000 people and the displacement of nearly one million.

Current funding sources and mechanisms for climate disasters in Mozambique include:

Contingency finance
- This is the main disaster funding source in the country, but it only covers the initial emergency phase and is limited
Donors
- Donations are a significant source of funding for extreme events but are difficult to monitor and predict, in part because there is no centralised monitoring and coordinating mechanism
Emergency loans
- These are organised in advance and can deliver funds in the event of an emergency. However, they are unpredictable, difficult to monitor and require long negotiations that cause delays in recovery and reconstruction
Contingency budget
- The Ministry of Public Works, Housing and Water Resources is the only sector to use a contingency budget, which allocates emergency funds to the recovery of roads and bridges.

How could the response to tropical cyclones be improved under a comprehensive loss and damage facility?

The Disaster Management Fund, which has been created by the Mozambican government to proactively budget for events rather than reallocate funds after the event. This has received funding in the form of a grant from the World Bank

Contingent loans are being discussed by the Mozambican government and World Bank and would provide immediate access to liquidity for emergency response and recovery following a disaster. This is especially important for providing immediate relief while funds are being obtained from other sources
Comprehensive rural insurance schemes, including microinsurance for agriculture, supported through entities such as the Global Index Insurance Facility, a multi-donor trust fund that supports smallholder farmers

Trust funds and loss and damage funds, such as relocation trust funds for those living in high-impact areas

National social protection schemes and other resilience measures for uplifting vulnerable communities. Examples might include retrofitting houses, medical centres and schools to make them storm proof. Investment in infrastructure for protecting communities from storm impacts could be funded through green bonds and impact investment funds

A comprehensive database on disasters as well as a sophisticated early-warning system could be developed with international expertise and financing. This would include means for disseminating information on imminent events, as rural areas are isolated and do not have reliable telecommunications.

Case study 3: Tropical cyclone Ana in Malawi

Together with Mozambique and Madagascar, Malawi experienced intense rainfall and winds from tropical cyclone Ana, affecting around one million people, destroying 115,388 hectares of crops and leaving 114,218 children without school facilities. Climate change increased the likelihood of this event in Malawi and is likely to increase the likelihood and intensity of tropical cyclones in the future. Malawi’s department of disaster management estimated that its four-month recovery plan required around USD 84 million. Malawi has contributed less than 0.01% of global carbon dioxide emissions since the Industrial Revolution.

Malawi is one of the poorest countries in the world, with an economy that is heavily reliant on agriculture, which employs up to 80% of the population. This makes it particularly vulnerable to climate shocks. Around 90% of people live in rural areas and are mostly engaged in rain-fed subsistence and smallholder farming. Around 2.3 million people face food insecurity and require assistance. Armed conflict in Northern Mozambique has also impacted more than one million Malawians.

How were affected communities supported following this event?

By the four-month recovery plan of Malawi’s department of disaster management, which received funding and technical support from humanitarian partners
A ‘flash appeal’ launched by humanitarian partners of the Malawian government, including the Malawi Red Cross, seven national NGOs, 26 international NGOs and 10 UN agencies, all of which aimed to provide assistance for those affected in the immediate aftermath of the event
By Oxfam and its humanitarian partners, who provided immediate relief in the form of cash, food, clean water and sanitation
Provision of health and nutrition kits by UNICEF
By other humanitarian organisations, such as Partners for Reproductive Justice, which provided health kits and mobile clinics for girls and women, and Christian organisations such as the Catholic Development Commission. which provided cash and non-food items, such as blankets and soap.

What are some of the major challenges in responding to, and preparing for, extreme weather events in Malawi?

Because of its high poverty and low level of economic development, Malawi is not resilient to climate disasters
As emphasised by the response to Ana, Malawi is highly reliant on humanitarian aid. The National Resilience Strategy of the Malawian government recognises the need for policy and new approaches to shift away from humanitarian aid and towards response plans and programmes that strengthen resilience to shocks
Though Malawi’s Department of Climate Change and Meteorological Services started issuing weather warnings on radio and television three days before the cyclone, many living in rural areas do not have access to radios or other telecommunications. The Department of Climate Change and Meteorological Services also cites issues including relaying weather information to those who are less educated, difficulties translating technical weather language into understandable formats, and a limited capacity for authorities to take action.

How could the response be improved through a dedicated loss and damage facility?

An analysis by the Loss and Damage Collaboration on a national loss and damage mechanism for Malawi found that:
- Key aspects missing in the loss and damage agenda at the government level include slow-onset events, which have been given no policy priority, and non-economic loss and damage. It suggested these impacts should be monitored and assessed in order to understand them better
- A loss and damage mechanism wouldn’t require the invention of completely new tools and approaches but should build upon existing institutions and frameworks
- The mechanism should include a financing facility that could track and prioritise which aspects of loss and damage need funding with a focus on the most vulnerable

Given the challenges faced by the disaster warning system currently in place, the facility could focus on improving resilience and responses by:
- Developing a comprehensive risk database and a sophisticated early-warning system that can reach rural communities. This could be both national and community-based to reach various sectors of society
- Investing in programmes that help improve the understanding of climate disasters and impacts in communities so that they are better equipped to respond to these events
- Developing multi-level contingency plans in order to improve disaster-response systems
- Strengthening coordination between various sectors of society to manage early response systems

To improve resilience against tropical cyclones, the facility could focus on:
- Developing and improving existing infrastructure to protect against floods and other climate impacts
- Providing facilities in anticipation of events, such as health facilities and shelters
- Relocating at-risk communities to suitable land above the flood line
- Uplifting local communities through resilience measures, such as national social protection schemes

Malawi is the ninth country to join the Africa Disaster Risk Financing Programme (ADRiFi), which, together with African Development Bank and African Risk Capacity (a specialised insurance company established by the African Union), aims to enhance government responses to climate shocks and strengthen the resilience of rural communities
This year, the African Development Bank approved a grant of USD 9.25 million for the financing of the ADRiFi in Malawi. The first part of the grant will come from the African Development Fund, while the ADRiFi multi-donor trust fund will provide the second part of the grant.

Compensation for, and recognition of, unavoidable loss and damage

These are various measures for compensating for and recognising loss and damage impacts that are unavoidable:

Recognition of impacts

Active remembrance of losses, such as through school curricula, museums and exhibitions
- If people are relocated, efforts should be made to maintain a sense of cultural identity
Encourage restorative dialogue
- Official apologies
- Truth and reconciliation conferences
Trauma counselling
Enabling access to abandoned sites.

Compensation for impacts

Support for rebuilding livelihoods and infrastructure
Support for developing alternative livelihoods
- For example, educating people on an alternative skill due to livelihood being lost, such as fishers who can no longer fish due to sea-level rise
Facilitating safe migration and resettlement.

These could be financed through curative finance mechanisms.

Case study 4: The Cape Town water crisis, South Africa

The Western Cape province of South Africa, where Cape Town is situated, experienced three years of consecutive drought from 2015 to 2017, leading to a major water shortage that almost saw the taps run dry for the four million residents of Cape Town. Unlike the tropical storms and floods mentioned in the previous case studies, this is an example of a slow-onset event that, despite having disastrous consequences, is often less likely to be on the political and policy agenda. However, scientists have found that climate change tripled the likelihood of this event and will increase the likelihood of it occurring again in the future. While the current water system in place in Cape Town was designed to provide sufficient water to mitigate drought once every 50 years, climate change has significantly increased drought frequency. This means the system is more vulnerable to drought than previously thought.

The water crisis had severe economic impacts for the region. Industries that were hit particularly hard include agriculture and tourism. The region produces 60% of the country’s agricultural exports and contributes 20% of domestic agricultural production. The estimated loss to agriculture alone during the water crisis was USD 0.4 billion and included the loss of 30,000 jobs. Cape Town is one of the most visited cities in the country and is a tourism hub of Africa, and the water crisis saw major declines in the numbers of overseas tourists visiting the region.

How might a comprehensive loss and damage facility improve the resilience of this system?

Investment in technologies and schemes

The system is entirely dependent on rainfall, making it highly vulnerable
Investment could focus on alternative technologies such as water de-salinisation plants, groundwater extraction and updated integrated urban water management, as well as the updating of existing infrastructure. This could be supported by:
- Technology and information sharing by international experts to help devise an integrated urban water management programme, funded by research grants
- Green bonds and impact investment funds to finance these technologies
- Investment in national social protection schemes, such as South Africa’s Working for Water project, which has already contributed significantly to improving drought resilience through removing alien vegetation from key water catchment areas

Support for farmers and other industries at risk

Investment in preventative measures, such as retrofitting or upgrading farms with improved capacity to store water
Investment in water-saving management approaches and tools
Empowering local governments and other entities to educate communities on water management

Emergency support in the event of another water crisis

Catastrophe-linked bonds
Disaster risk insurance
Contingency finance.

IPCC Sixth Assessment Report: Impacts, adaptation and vulnerability

February 18, 2022 by ZCA Team Leave a Comment

The Intergovernmental Panel on Climate Change (IPCC) has released the second part of its four-part, Sixth Assessment Report (AR6) in February 2022. The Working Group II (WGII) report is the most comprehensive review of climate impacts – and how much we can adapt to them – since its 2014 5th Assessment (AR5).¹ Line-by-line approval by governments as well as acceptance of the underlying scientific report ensures high credibility in both science and policy communities and ownership by governments.

The report summarises the current understanding of how climate change impacts humans and ecosystems. Compared to previous IPCC reports, WGII integrates more from economics and the social sciences and highlights more clearly the important role of social justice in adapting to climate change.

Based on publicly-available literature, this briefing covers some of the major developments in our knowledge of climate change impacts and adaptation since AR5.

1. Climate change is severely impacting people and the ecosystems we depend on

In August 2021, the IPCC published the first part of its 6th assessment report (WGI – Physical Science). WGI found that greenhouse gases from human activities had caused approximately 1.1°C of global warming by 2010-19 compared to 1850-1900, and that global temperature is expected to reach or exceed 1.5°C of warming over the next 20 years. Dubbed a “code red” for humanity by the UN’s António Guterres, the report left no space for doubt – climate change is unequivocally the result of human activities and at the current 1.1°C of global warming we are already seeing increasing impacts, including from extreme weather events such as heatwaves, droughts and flooding across the world. It also warned of abrupt responses and tipping points in the climate system (such as increased glacial melting of approximately 600 Gt of ice annually).

A Special Report on 1.5°C (SR1.5) emphasised that the world will face severe climate impacts even with 1.5°C of warming, and the effects get significantly worse with 2°C and worse still at higher levels of warming. The expectation is that WGII will pick up on explaining and outlining these risks, as recent research has shown that exceeding the 1.5°C temperature limit could lead to irreversible impacts, like the loss of species and biomes, with serious consequences, not least for food security, for humans.

Compared to the last IPCC Assessment in 2014, AR6 sees an increased focus on regional impacts, benefiting from improved models and knowledge of how global impacts manifest regionally. WGI already presented the main physical climate impacts projected for the world’s regions. For example, the African continent is already experiencing higher warming and sea level rise than the world average. In the next decade, Africa will see more frequent and intense heatwaves (up to five times more common in 2050 than today) as well as heavier precipitation, more frequent and intense droughts, and more common and severe coastal flooding. In Europe, the frequency and intensity of hot extremes is increasing, and will continue to do so, while glaciers and snow cover will continue to disappear. In North and Central America, for example, the IPCC states that tropical cyclones and heavy rainfall will become ever more frequent as the world continues to warm.²

Since AR5, more research has been done to connect the physical impacts of climate change to socio-economic and justice implications. Building on findings in the WGI report, WGII will go much further by describing the damaging impacts of climate change on humans, ecosystems and the economy, charting how climate change is disrupting livelihoods and the systems we depend on.

2. Extreme weather is causing unprecedented damage

Since the AR5 WGII report, extreme weather events that are caused or exacerbated by climate change have caused widespread and severe damage. One of the main developments in climate science since the last IPCC report has been the expansion of ‘attribution literature’. Attribution studies can tell us if, and how, climate change made a particular extreme weather event more likely or more intense. The expanded attribution literature shows that heatwaves, droughts, tropical cyclones and even locust swarms are directly linked to climate change caused by human activities.

Many of the extreme weather phenomena that the world experienced in 2021 have been attributed to human-induced climate change. The Pacific Coast heatwave in June 2021 was found to be ‘virtually impossible’ without climate change. Climate change made the massive wildfires that ripped through California and Oregon, extreme heat across the Mediterranean, and the severe flooding that Western Europe experienced much more likely. In September, the National Oceanic and Atmospheric Administration (NOAA) linked the most severe southwest USA drought in history to climate change. Meanwhile in Siberia, wildfires released about as much CO₂ as Germany produces in a year. By November, the intense rain and flooding in British Columbia, ‘made worse because of climate change’, forced 17,000 from their homes.

It is also clear that the world’s poorest and most vulnerable are at greater risk, including from mortality and other health consequences of extreme weather. Over the last decade, the mortality from floods, drought and storms has been up to 15 times higher in the most affected countries, including most of Africa and large parts of Central America, compared to less affected countries (like those located in western and northern Europe). Between 1970 and 2019, more than 91% of the deaths from weather, climate and water hazards across the world have been in developing nations. Emerging research has also found an increasing mental health burden of extreme weather. Post-traumatic stress disorders, anxiety, grief and survivor guilt are among some of the mental health challenges observed in people after extreme weather events.

Large scale human migration and displacement could be driven by more frequent resource scarcity, damage to infrastructure from extreme weather events, and increases in the frequency and severity of disease outbreaks. Human populations are concentrated in narrow climate bands, with most people living in places where the average annual temperature is about 11°C-15°C and a smaller number of people living where the average temperature is about 20°C-25°C. The climate hazard of rising temperatures alone is predicted to force 3.5 billion people to live outside the climatic zones where humans have thrived for 6,000 years. Higher temperature is projected to increase asylum applications in the EU by 28%. In 2018, the World Bank estimated that three regions (Latin America, sub-Saharan Africa, and Southeast Asia) will generate 143 million more climate migrants by 2050. The most foreseeable case of migration as a response to climate impacts will likely be the Pacific Islands. The sea level rise (at a rate of 12 millimetres per year) has already submerged eight islands in the western Pacific. Two more are on the brink of disappearing, prompting a wave of migration to larger countries. Despite this, no international agreements exist on how to protect those who are displaced and forcibly moved as a result of climate change. In 2015, a family from Kiribati applied for refugee status in New Zealand, citing climate change as the reason for the forced migration. Their application was originally denied by the New Zealand Immigration and Protection Tribunal, the Court of Appeal and the Supreme Court.

3. Impacts are getting worse, hitting marginalised people the hardest

Climate risks that negatively impact ecosystems will further limit the services these systems provide to society, and could reduce access to energy, healthcare, water and international trade. Building climate resilience is, therefore, an essential component of sustainable development, and WGII is expected to discuss the core principles of climate resilience development such as the trade-offs and synergies of sustainable development, adaptation and mitigation, and the social effects of greenhouse gas emissions. Research has shown that human-induced climate change could occur across 80% of the world’s land area, where 85% of the population reside. These impacts will propagate across national boundaries through global supply chains, which are increasingly compromised by climate impacts. In the US, the annual costs to supply chains from natural disasters rose to a record high of USD 95 billion in 2020. These costs will continue to grow. For example, McKinsey predicts that a collapse in the global supply of semiconductors (critical to the global tech industry) from a hurricane will grow up to four times by 2040 due to climate change.

Food production systems are also under increasing pressure. Human activities have already changed 75% of the Earth’s land, and nearly 75% of freshwater resources are now devoted to crop or livestock production. Today, 25% of the total land area of the world is degraded. Land degradation has reduced the productivity of 23% of the global land surface, with global agriculture crop production increasing by 300% since the 1970s. The IPCC’s Special Report on Land (SRCCL) estimated that soil erosion from agricultural fields is 10 to 20 times (no tillage) to more than 100 times (conventional tillage) higher than the soil formation rate. Scientists have warned 24 billion tons of fertile soil are lost each year, largely due to unsustainable agriculture practices. If this trend continues, 95% of the Earth’s land areas could become degraded by 2050. Studies that separate out the effects of climate change alone have shown that yields of some crops (like maize and wheat) in many lower-latitude regions have declined. Increasing temperatures will continue to impact food production, estimating up to a 29% increase in the cost of cereals by 2050, depending on the amount of warming. These price increases will impact consumers globally, with low-income consumers at particular risk of malnutrition.

As a result of climate change and land degradation, one million animal and plant species are now threatened with extinction, many within decades – more than at any time in human history, according to the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services (IPBES). Today, only 15% of land and just under 8% of the ocean are under some form of ecosystem protection. IPBES concludes that the loss of ecosystems has made human communities more vulnerable to climate impacts. Continued overlapping climate change with non-climatic pressures like land-use change, deforestation, infrastructure development, resource extraction, overfishing and pollution will continue to threaten ecosystems and people’s livelihoods. Climate change currently affects at least 10,967 species on the International Union for Conservation of Nature (IUCN)’s Red List of Threatened Species. The Bramble Cay melomys (a genus of rodents) is the first mammal reported to have gone extinct as a direct result of climate change.

Since AR5, more research has shown that the most marginalised, both economically and socially, are hit first and hardest by climate impacts, both in the global south and north. Climate change could cause GDP losses of 64% in the world’s most vulnerable countries, and the impacts of climate change may further exacerbate marginalisation and injustices. On a global scale, new research shows the vulnerabilities of the urban poor. According to one study, if greenhouse gases continue on their current trajectory, 215 million urban poor around the world will be exposed to average summer temperatures of over 35°C – an eightfold rise from today – which will increase the risks of heat mortality.

Worryingly, scientists say that ‘compound extremes’ will become more common in a warming world, and that these events are likely to cause more suffering than we would see from individual events alone. Compound extremes arise when multiple climate hazards (such as extreme temperature and precipitation) occur simultaneously in the same place, affect multiple regions at the same time, or occur in a sequence (commonly referred to as cascading events). Climate hazards can be also compounded by other human impacts, such as pollution, habitat fragmentation and environmental degradation. For example, the rise in concurrent drought and heatwave events was especially observed in southern and central Africa over the last decade, and the impact of these compound events can last longer as a result of climate change.³ An initial rise in temperature can trigger a cascade of climate impacts. For example, sustained higher temperatures that decrease in soil moisture will suppress plant growth, which in turn suppresses rainfall, leading to more drought in what is known as an escalating ‘feedback loop’. In recent years in California, a combination of droughts and heatwaves have led to wildfires and in some cases, been followed by heavy rain and landslides.

Academic literature exploring the complex connections between climate change, extreme weather, migration and conflict has also expanded. The civil war in the Darfur region of Sudan is an example of a conflict researchers think was made worse, or even triggered, by a changing climate. In 1983-84, a drought fuelled a famine that killed over 100,000 people and led to mass ecological migration, mainly towards southern Darfur. As people migrated into different regions, ethnic polarisation disrupted regional harmony and triggered conflict. Migration is a complex topic, which cannot be simply attributed to one cause. However, researchers have focused on the increased risks of migration that small island states and coastal cities will face due to climate change. One estimate suggests that between 17 million and 72 million people may have to relocate from coastal settlements if sea levels rise somewhere between 0.3 and 1.7 metres.

4. Adaptation is vital, but far more is needed

Since AR5, there has been an increase in adaptation activities, including by governments, businesses and civil society, with most in response to extreme weather events. For example, an EU Commission-funded project by the WHO and the London School of Tropical Medicine charts the need to shift from disaster response to risk management for flooding in Europe, including better warning systems and health protection measures. However, though adaptation options are available across all sectors and can reduce the risks of climate change, adaptation has so far been dominated by small changes to current systems, rather than the transformative changes that experts say we needed.

Adaptation and biodiversity are closely linked and implementing nature-based solutions (NbS) can create co-benefits for adaptation to climate change, for nature and its contribution to people. However, trade-offs can arise if climate mitigation policy encourages NbS with low biodiversity value, such as afforestation with non-native monocultures. In 2021, the IPBES and IPCC found that the “mutual reinforcing of climate change and biodiversity loss means that satisfactorily resolving either issue requires consideration of the other.” One of the best documented co-benefits of adaptation is the positive impact on population health, both physical and mental, when investing in nature-based and green infrastructure in cities. Similarly, scientists found that global mangroves are responsible for storing a stock of 6 billion tonnes of carbon, and that restoring mangroves protects against flooding and is two-to five-times cheaper than conventional engineered sea level rise protection. As a result, several nations, including Indonesia, India, Bangladesh and Sri Lanka, are investing in mangrove restoration for adaptation.

Scientists have made significant progress in estimating the costs of climate change impacts, finding that adaptation can be cost effective if it is done in a timely manner. The upcoming IPCC report is likely to reflect that, although numbers still vary widely, the costs of impacts are now thought to be much higher than AR5 suggested. Yet despite the benefits to adaptation (and the threat of tipping points), currently most climate finance is directed to mitigation and there remains a large finance gap (public and private) between the amount of money flowing to developing countries and the amount needed. Estimated adaptation costs in developing countries are five to 10 times greater than current public adaptation finance, and the adaptation finance deficit grows at higher levels of warming. It is expected that the WGII report will discuss some of the fundamental barriers to access private finance for adaptation, such as the fact that private investment tends to gravitate to opportunities where revenues are highest and risks are lowest, meaning it is unlikely to target the most vulnerable developing nations or non-market sectors, where adaptation is needed the most.

Although adaptation is a necessary solution to the climate impacts we are already experiencing, previous IPCC reports have also emphasised the limitations of adaptation. The Paris Agreement refers to impacts of climate change that have not been, or cannot be, avoided through mitigation and adaptation and that are considered the third pillar of climate action. The AR5 WGII report discussed the losses and damages associated with ‘hard’ (biophysical, institutional, financial, social and cultural) and ‘soft’ (technological and socioeconomic) limits to adaptation. For example, there are hard physical limits to how much Small Island Developing States (SIDS) can adapt to rising sea levels, and their vulnerability to climate change is likely to lead to forced migration from these countries. For species and ecosystems, there may be hard limits to the physiological capacity of individual organisms to adapt to changes in the climate. Often, socioeconomic barriers stop the poorest and most vulnerable people from being able to adapt. The SR1.5 built upon these definitions and assessed the soft and hard adaptation barriers for impacts under a 1.5°C and 2°C of global warming, and we expect the issue of equity and justice in responding L&D to be the focus of the upcoming AR6 report.

5. The costs of inaction far exceed those of mitigation and adaptation

The need for, and success of, adaptation is closely linked to the level of mitigation we achieve. The AR5 WGII report highlighted that the overall risks of impacts can be reduced by limiting the rate and magnitude of climate change, which will in turn reduce the scale of adaptation required. Studies have found per capita GDP would be 5% higher by 2100 if temperatures are stabilised at 1.5°C above pre-industrial temperatures rather than 2°C and limiting global warming to 2°C instead of 4°C could save USD 17.5 trillion a year globally by 2100. Conversely, the cost of failing to limit warming to 1.5°C rises dramatically – from USD 1.3 trillion a year of inaction in 2010 to over USD 5 trillion a year in 2020.

Adaptation is already necessary and will be harder or impossible with greater warming. The economic damage that climate change and extreme weather events cause is already significant: The cost of climate impacts in Central America in 2010 ranged from 2.9% of GDP for Guatemala to 7.7% for Belize; Tropical Cyclone Pam caused loss and damage to Vanuatu’s agricultural sector estimated at 64.1% of GDP in 2015; while Hurricane Maria caused loss and damage totalling 224% of Dominica’s GDP in 2016. Nearly half the global population is already living in potential water-scarce areas at least one month a year and this could increase to some 4.8 billion – 5.7 billion by 2050.

The WGII report discusses how a delay in mitigation and adaptation actions will threaten sustainable development, as climate change impacts and responses are closely linked to social well-being, economic prosperity and environmental protection. Human-induced climate change may lead to a decline in agricultural yields, water scarcity, food insecurities, reduced livelihoods and displacement of communities, and the impacts will not be felt equally by all. Climate change is projected to increase the number of people experiencing extreme poverty from 32 million to 132 million by 2030. The gap between the economic output of the world’s richest and poorest countries is 25% larger today than it would have been without global warming. If climate change is not addressed through global reduction in emissions, global income inequality is predicted to widen as a result of decreases in global incomes.

6. Further reading: Explainers and scientific papers

The list below summarises some important commentaries and scientific papers, focusing on those published in the last two years. It is not a comprehensive review of the scientific literature. To explore the specific topics further, please refer to the reference lists within these publications.