3

Megafires — Climate change
forces fire extremes to reach new
dimensions with extreme impacts

Key new insights

We are entering a new age of intensifying extreme fire regimes (megafires). It is likely that these are induced, and certainly exacerbated, by anthropogenic climate change.
Several megafires have been observed across very diverse regions from high to low latitudes, and are now impacting ecosystems that typically do not have a history of wildfires.
Megafires can affect entire biomes with unprecedented impacts on flora and fauna, threatening also more fire-sensitive ecosystems such as the World Heritage–listed Gondwana rainforests of Australia.
Large greenhouse gas emissions released by megafires enhance positive fire-climate feedback, which sustain and worsen conditions that increase the likelihood of even more devastating wildfires.
Large smoke plumes and aerosols from megafires can impact wide areas due to long-range transport both in the troposphere and stratosphere.
Worsening fire regimes (more frequent fires, more intense fires) come with increased risks to respiratory and cardiovascular health, birth outcomes and mental health for rural and urban communities.

Key new insights

We are entering a new age of intensifying extreme fire regimes (megafires). It is likely that these are induced, and certainly exacerbated, by anthropogenic climate change.
Several megafires have been observed across very diverse regions from high to low latitudes, and are now impacting ecosystems that typically do not have a history of wildfires.
Megafires can affect entire biomes with unprecedented impacts on flora and fauna, threatening also more fire-sensitive ecosystems such as the World Heritage–listed Gondwana rainforests of Australia.
Large greenhouse gas emissions released by megafires enhance positive fire-climate feedback, which sustain and worsen conditions that increase the likelihood of even more devastating wildfires.
Large smoke plumes and aerosols from megafires can impact wide areas due to long-range transport both in the troposphere and stratosphere.
Worsening fire regimes (more frequent fires, more intense fires) come with increased risks to respiratory and cardiovascular health, birth outcomes and mental health for rural and urban communities.

Insights explained

New scientific advances confirm previous warnings that human-induced climate change is intensifying fire regimes. There have been increases in fire extent, intensity and the duration of the fire season, as well as a change in the available fuels, resulting in an increased frequency and intensity of fires. Megafires, high-intensity wildfires that spread uncontrolled over large areas, reaching extreme fire intensities, are likely to be increasingly frequent. Megafires cause greenhouse gas and aerosol emissions, which are unprecedented for the affected biome, and impact air quality on local and continental scales.

Researchers have recently been able to attribute fire and megafire events more clearly to human interference – such as the 2021 wildfires in western North America that were preconditioned by an extreme heatwave. Evidence for human influence is found in fire seasons of unprecedented magnitude in the modern era in regions and countries as diverse as California, Australia, the Mediterranean basin, Canada and the Arctic. It is now possible, with at least medium confidence, to attribute human influence on weather events, namely extreme drought, heat, lightning activities and often high winds, that increase the fire risk. The IPCC Working Group I Sixth Assessment Report (IPCC AR6 (WGI)) projects future increases of fire weather with medium or high confidence on every inhabited continent, primarily due to higher temperatures and reduced precipitation.^[1]Seneviratne, S. I., Zhang, X., Adnan, M., Badi, W., Dereczynski, C., Di Luca, A., Ghosh, S., Iskandar, I., Kossin, J., Lewis, S., Otto, F., Pinto, I., Satoh, M., Vicente-Serrano, S. M., Wehner, M., … Continue reading There is medium confidence that there is a positive carbon-climate feedback loop with fires releasing greenhouse gases enhancing the drier and fire-prone conditions that favour fires.^[2]Canadell, J. G., Monteiro, P. M. S., Costa, M. H., Cotrim da Cunha, L., Cox, P. M., Eliseev, A. V., Henson, S.; Ishii, M., Jaccard, S., Koven, C., Lohila, A., Patra, P. K., Piao, S., Rogelj, J., … Continue reading

Recent fires have caused significant impacts on human health. Wildfire smoke is known to affect respiratory health, and there is growing evidence of impacts on cardiovascular health, mortality, birth outcomes and mental health. Smoke from wildfires also affects local and distant air quality. The 2019-2020 Australian wildfires affected New Zealand and South America, and smoke from Siberian fires has affected North America. Current assessments estimate over 677,000 deaths per year globally from landscape fires with the largest contribution from the Arctic, South East Asia, Central and West Africa and the Amazon.^[3]Roberts, G., and Wooster, M. J. (2021): Global impact of landscape fire emissions on surface level PM2.5 concentrations, air quality exposure and population mortality. In Atmospheric Environment, … Continue reading

As climate changes, the occurrence of megafires is not constrained to fire-prone ecosystems alone. A change in tropical forests’ moisture, for instance, may promote much larger fires. Changing fire regimes will have important consequences for the world’s biodiversity, regional human health and the global climate system.

Insights explained

New scientific advances confirm previous warnings that human-induced climate change is intensifying fire regimes. There have been increases in fire extent, intensity and the duration of the fire season, as well as a change in the available fuels, resulting in an increased frequency and intensity of fires. Megafires, high-intensity wildfires that spread uncontrolled over large areas, reaching extreme fire intensities, are likely to be increasingly frequent. Megafires cause greenhouse gas and aerosol emissions, which are unprecedented for the affected biome, and impact air quality on local and continental scales.

Researchers have recently been able to attribute fire and megafire events more clearly to human interference – such as the 2021 wildfires in western North America that were preconditioned by an extreme heatwave. Evidence for human influence is found in fire seasons of unprecedented magnitude in the modern era in regions and countries as diverse as California, Australia, the Mediterranean basin, Canada and the Arctic. It is now possible, with at least medium confidence, to attribute human influence on weather events, namely extreme drought, heat, lightning activities and often high winds, that increase the fire risk. The IPCC Working Group I Sixth Assessment Report (IPCC AR6 (WGI)) projects future increases of fire weather with medium or high confidence on every inhabited continent, primarily due to higher temperatures and reduced precipitation.^[4]Seneviratne, S. I., Zhang, X., Adnan, M., Badi, W., Dereczynski, C., Di Luca, A., Ghosh, S., Iskandar, I., Kossin, J., Lewis, S., Otto, F., Pinto, I., Satoh, M., Vicente-Serrano, S. M., Wehner, M., … Continue reading There is medium confidence that there is a positive carbon-climate feedback loop with fires releasing greenhouse gases enhancing the drier and fire-prone conditions that favour fires.^[5]Canadell, J. G., Monteiro, P. M. S., Costa, M. H., Cotrim da Cunha, L., Cox, P. M., Eliseev, A. V., Henson, S.; Ishii, M., Jaccard, S., Koven, C., Lohila, A., Patra, P. K., Piao, S., Rogelj, J., … Continue reading

Recent fires have caused significant impacts on human health. Wildfire smoke is known to affect respiratory health, and there is growing evidence of impacts on cardiovascular health, mortality, birth outcomes and mental health. Smoke from wildfires also affects local and distant air quality. The 2019-2020 Australian wildfires affected New Zealand and South America, and smoke from Siberian fires has affected North America. Current assessments estimate over 677,000 deaths per year globally from landscape fires with the largest contribution from the Arctic, South East Asia, Central and West Africa and the Amazon.^[6]Roberts, G., and Wooster, M. J. (2021): Global impact of landscape fire emissions on surface level PM2.5 concentrations, air quality exposure and population mortality. In Atmospheric Environment, … Continue reading

As climate changes, the occurrence of megafires is not constrained to fire-prone ecosystems alone. A change in tropical forests’ moisture, for instance, may promote much larger fires. Changing fire regimes will have important consequences for the world’s biodiversity, regional human health and the global climate system.

Background

Wildfires are an intrinsic feature of many ecosystems around the world, and are a prerequisite for many plant species to reproduce. Many factors affect whether a wildfire starts and how severe it is, such as weather, vegetation structure (fuel availability), terrain (or topography), land and fire management practices and human presence that may – on purpose or by accident – ignite a fire. Wildfires occur in some ecosystems, such as Australian savannahs, almost annually; in Australian temperate forests they occur multiple times in a decade (potentially increasing in frequency now), and in ecosystems such as undisturbed rainforests wildfires only rarely occur, usually on centennial scales, such as in boreal forests in North America and in Siberia (100-300 years between events). In Siberian boreal forests normal fire conditions burn only the forest floor, leaving standing trees alive. Extreme drought conditions that burn entire forest stands (crown fires – burning even forest canopies) used to occur only every 10-15 years and affected 3-10 million hectares in Siberia. Climate change is impacting the frequency and severity of fires, causing extreme fire years to become more extreme.

Background

Wildfires are an intrinsic feature of many ecosystems around the world, and are a prerequisite for many plant species to reproduce. Many factors affect whether a wildfire starts and how severe it is, such as weather, vegetation structure (fuel availability), terrain (or topography), land and fire management practices and human presence that may – on purpose or by accident – ignite a fire. Wildfires occur in some ecosystems, such as Australian savannahs, almost annually; in Australian temperate forests they occur multiple times in a decade (potentially increasing in frequency now), and in ecosystems such as undisturbed rainforests wildfires only rarely occur, usually on centennial scales, such as in boreal forests in North America and in Siberia (100-300 years between events). In Siberian boreal forests normal fire conditions burn only the forest floor, leaving standing trees alive. Extreme drought conditions that burn entire forest stands (crown fires – burning even forest canopies) used to occur only every 10-15 years and affected 3-10 million hectares in Siberia. Climate change is impacting the frequency and severity of fires, causing extreme fire years to become more extreme.

Implications

At a global level, decision-makers are urged to:

limit global warming with all measures possible to decrease the risk of more frequent and intense megafires.

At a regional level, governments need to:

revise and adapt fire management planning to account for a diverse range of affected ecosystems, which requires land management methods that are region- and context-specific.

At national and local levels, policymakers need to:

include megafires and their impact on greenhouse gas emissions in the budgets for the 1.5°C-target;
implement monitoring and forecasting systems of weather conditions and wildfires, which may support adaptation to the devastating effects of these fires;
provide protection measures by controlling and penalizing illegal deforestation where fire is used as a land clearing technique;
adapt forest management methods such as forest fuel treatments, the intentional reduction of material that burns in fire-prone forest areas, to local biomes and climatic conditions;
consider collaborating with indigenous communities to re-engage with traditional land management practices, such as cultural burning;
increase the resilience of communities in affected areas (taking account of an increased fire risk when planning, building and improving infrastructure);
consider techniques to reduce exposure to PM_2.5 from wildfire such as the use of air cleaners in indoor spaces, thereby protecting people’s health;
increase monitoring of air pollution, including with low-cost sensors, and the development of better forecasting to warn people about air pollution levels.

Implications

At a global level, decision-makers are urged to:

limit global warming with all measures possible to decrease the risk of more frequent and intense megafires.

At a regional level, governments need to:

revise and adapt fire management planning to account for a diverse range of affected ecosystems, which requires land management methods that are region- and context-specific.

At national and local levels, policymakers need to:

include megafires and their impact on greenhouse gas emissions in the budgets for the 1.5°C-target;
implement monitoring and forecasting systems of weather conditions and wildfires, which may support adaptation to the devastating effects of these fires;
provide protection measures by controlling and penalizing illegal deforestation where fire is used as a land clearing technique;
adapt forest management methods such as forest fuel treatments, the intentional reduction of material that burns in fire-prone forest areas, to local biomes and climatic conditions;
consider collaborating with indigenous communities to re-engage with traditional land management practices, such as cultural burning;
increase the resilience of communities in affected areas (taking account of an increased fire risk when planning, building and improving infrastructure);
consider techniques to reduce exposure to PM_2.5 from wildfire such as the use of air cleaners in indoor spaces, thereby protecting people’s health;
increase monitoring of air pollution, including with low-cost sensors, and the development of better forecasting to warn people about air pollution levels.

9,000

plant species (more than one-third of all Australian species), 832 vertebrate fauna species, including 21 threatened species were affected across the 2019/20 fire grounds in Australia.

0.67

gigatonnes of carbon stocks net loss of biomass in the Amazon from 2010-2019, largely due to fires, contributing to the conversion of the Amazon from a carbon sink into a source.

35%

more CO₂ released from Arctic wildfires in the first 8 months of 2020 compared to the entire previous year (2019).

9,000

plant species (more than one-third of all Australian species), 832 vertebrate fauna species, including 21 threatened species were affected across the 2019/20 fire grounds in Australia.

0.67

gigatonnes of carbon stocks net loss of biomass in the Amazon from 2010-2019, largely due to fires, contributing to the conversion of the Amazon from a carbon sink into a source.

35%

more CO₂ released from Arctic wildfires in the first 8 months of 2020 compared to the entire previous year (2019).

Figure 3. Cumulated selected fires larger than 40,000 ha between November 2019 and August 2021. 40,000 hectares is 4% of 1 million hectares.

Figure 3. Cumulated selected fires larger than 40,000 ha between November 2019 and August 2021. 40,000 hectares is 4% of 1 million hectares.

Spotlight: Selected megafires

Australia

After record heat and drought, Australia experienced abnormally severe fires of unprecedented extent, including the largest single-ignition fire on record, which was greater than 500,000 hectares, in the season of 2019-2020. An estimated 715 (range 517-867) Mt gross CO₂ in total were emitted from these fires. Furthermore, these megafires affected entire biomes in southern and eastern Australia with unprecedented impacts on flora and fauna. The fires not only affected savannahs and eucalypt forests that are well adapted to wildfire, but also more fire-sensitive ecosystems, threatening the World Heritage–listed Gondwana rainforests.

Arctic and Siberia

In the Arctic Circle and Siberia, a rise in arctic temperatures and dry lightning caused large areas to burn. In 2019 about 10 million hectares – more than the size of Portugal – burned in Siberia and the Russian Arctic. This was followed by another extreme fire year in 2020 when nearly 14 million hectares burned in the region. Extreme fires occurred again in 2021. Altogether, the fires in the Arctic and Siberia released about 175 Mt of gross CO₂ in 2019 and nearly 250 Mt of gross CO₂ in 2020.

Brazil

In the world’s largest wetland, the Brazilian Pantanal, there was a 245% increase in burned areas in 2020 compared to the previous 10 years. Reasons for this are extreme drying (due to 50% less rain than in the previous year) and intensified anthropogenic burning for intentional legal and illegal deforestation to reform pastures or make room for agriculture. It led to emissions of 115 Mt of gross CO₂ and 524 tonnes of harmful fine PM_2.5. Populations of many animal and plant species were affected, many of which are rare or endemic. There is growing concern that the fragile ecosystem of the Pantanal area may never recover.

United States

Since 2018, the US south-west has experienced some of the worst fires ever seen in the region. Californian megafires burned for months and became the seven largest wildfires ever recorded until 2020. The largest megafire, the August complex fire, burned more than 400,000 hectares of different forest and shrubland types. Such high fire severity over an extremely large area puts the recovery of plants and animals, most of them rare or endemic, under threat. Smoke released by these fires reached critical levels for human health along the US west coast, with San Francisco covered under an orange sky for days. The smoke travelled across the northern hemisphere and aerosol particles from the fires were measured as far away as Germany. The 2020 California and Oregon wildfires led to excess carbon emissions of at least 30 Mt of gross CO₂ in a single year.

Spotlight: Selected megafires

Australia

After record heat and drought, Australia experienced abnormally severe fires of unprecedented extent, including the largest single-ignition fire on record, which was greater than 500,000 hectares, in the season of 2019-2020. An estimated 715 (range 517-867) Mt gross CO₂ in total were emitted from these fires. Furthermore, these megafires affected entire biomes in southern and eastern Australia with unprecedented impacts on flora and fauna. The fires not only affected savannahs and eucalypt forests that are well adapted to wildfire, but also more fire-sensitive ecosystems, threatening the World Heritage–listed Gondwana rainforests.

Arctic and Siberia

In the Arctic Circle and Siberia, a rise in arctic temperatures and dry lightning caused large areas to burn. In 2019 about 10 million hectares – more than the size of Portugal – burned in Siberia and the Russian Arctic. This was followed by another extreme fire year in 2020 when nearly 14 million hectares burned in the region. Extreme fires occurred again in 2021. Altogether, the fires in the Arctic and Siberia released about 175 Mt of gross CO₂ in 2019 and nearly 250 Mt of gross CO₂ in 2020.

Brazil

In the world’s largest wetland, the Brazilian Pantanal, there was a 245% increase in burned areas in 2020 compared to the previous 10 years. Reasons for this are extreme drying (due to 50% less rain than in the previous year) and intensified anthropogenic burning for intentional legal and illegal deforestation to reform pastures or make room for agriculture. It led to emissions of 115 Mt of gross CO₂ and 524 tonnes of harmful fine PM_2.5. Populations of many animal and plant species were affected, many of which are rare or endemic. There is growing concern that the fragile ecosystem of the Pantanal area may never recover.

United States

Since 2018, the US south-west has experienced some of the worst fires ever seen in the region. Californian megafires burned for months and became the seven largest wildfires ever recorded until 2020. The largest megafire, the August complex fire, burned more than 400,000 hectares of different forest and shrubland types. Such high fire severity over an extremely large area puts the recovery of plants and animals, most of them rare or endemic, under threat. Smoke released by these fires reached critical levels for human health along the US west coast, with San Francisco covered under an orange sky for days. The smoke travelled across the northern hemisphere and aerosol particles from the fires were measured as far away as Germany. The 2020 California and Oregon wildfires led to excess carbon emissions of at least 30 Mt of gross CO₂ in a single year.

Satellite images

Image 1: Bushfires on December 31, 2019 burning along the east coast of Australia. The brown area is burned vegetation with a width of about 50 km and a length of 100 km. Source: European Space Agency (ESA), contains modified Copernicus Sentinel data (2019), processed by ESA, CC BY-SA 3.0 IGO

Image 2: Wildfires on August 19, 2020 burning on the West Coast of the USA in California. Source: European Space Agency (ESA), contains Copernicus Sentinel data (2020), processed by ESA, CC BY-SA 3.0 IGO

Image 3: Wildfires on July 25, 2021 in the Sakha Republic, Siberia (Russia) close to the Arctic cycle. Source: European Space Agency (ESA), contains Copernicus Sentinel data (2021), processed by ESA, CC BY-SA 3.0 IGO

Image 4: Wildfires on August 1, 2020 in the Amazon in Brazil. Source: NASA Earth Observatory, image acquired by Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite.

Satellite images

Image 1: Bushfires on December 31, 2019 burning along the east coast of Australia. The brown area is burned vegetation with a width of about 50 km and a length of 100 km. Source: European Space Agency (ESA), contains modified Copernicus Sentinel data (2019), processed by ESA, CC BY-SA 3.0 IGO

Image 1: Bushfires on December 31, 2019 burning along the east coast of Australia. The brown area is burned vegetation with a width of about 50 km and a length of 100 km. Source: European Space Agency (ESA), contains modified Copernicus Sentinel data (2019), processed by ESA, CC BY-SA 3.0 IGO

Image 3: Wildfires on July 25, 2021 in the Sakha Republic, Siberia (Russia) close to the Arctic cycle. Source: European Space Agency (ESA), contains Copernicus Sentinel data (2021), processed by ESA, CC BY-SA 3.0 IGO

Image 4: Wildfires on August 1, 2020 in the Amazon in Brazil. Source: NASA Earth Observatory, image acquired by Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite.

References

 [+]

References
↑1, ↑4	Seneviratne, S. I., Zhang, X., Adnan, M., Badi, W., Dereczynski, C., Di Luca, A., Ghosh, S., Iskandar, I., Kossin, J., Lewis, S., Otto, F., Pinto, I., Satoh, M., Vicente-Serrano, S. M., Wehner, M., and Zhou, B. (2021): Weather and Climate Extreme Events in a Changing Climate. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield, T. Yelekçi, O., Yu, R., and Zhou, B. (Eds.), Cambridge University Press.
↑2, ↑5	Canadell, J. G., Monteiro, P. M. S., Costa, M. H., Cotrim da Cunha, L., Cox, P. M., Eliseev, A. V., Henson, S.; Ishii, M., Jaccard, S., Koven, C., Lohila, A., Patra, P. K., Piao, S., Rogelj, J., Syampungani, S., Zaehle, S., and Zickfeld, K. (2021): Global Carbon and other Biogeochemical Cycles and Feedbacks. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield, T. Yelekçi, O., Yu, R., and Zhou, B. (Eds.), Cambridge University Press.
↑3, ↑6	Roberts, G., and Wooster, M. J. (2021): Global impact of landscape fire emissions on surface level PM2.5 concentrations, air quality exposure and population mortality. In Atmospheric Environment, 252, p. 118210. DOI: 10.1016/j. atmosenv.2021.118210.
↑7, ↑8	Qin, Y., Xiao, X., Wigneron, J.-P., Ciais, P., Brandt, M., Fan, L., Li, X., Crowell, S., Wu, X., Doughty, R., Zhang, Y., Liu, F., Sitch, S., and Moore, B. (2021): Carbon loss from forest degradation exceeds that from deforestation in the Brazilian Amazon. In Nature Climate Change, 11 (5), pp. 442–448. DOI: 10.1038/s41558-021-01026-5.

References

 [+]

References
↑1, ↑4	Seneviratne, S. I., Zhang, X., Adnan, M., Badi, W., Dereczynski, C., Di Luca, A., Ghosh, S., Iskandar, I., Kossin, J., Lewis, S., Otto, F., Pinto, I., Satoh, M., Vicente-Serrano, S. M., Wehner, M., and Zhou, B. (2021): Weather and Climate Extreme Events in a Changing Climate. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield, T. Yelekçi, O., Yu, R., and Zhou, B. (Eds.), Cambridge University Press.
↑2, ↑5	Canadell, J. G., Monteiro, P. M. S., Costa, M. H., Cotrim da Cunha, L., Cox, P. M., Eliseev, A. V., Henson, S.; Ishii, M., Jaccard, S., Koven, C., Lohila, A., Patra, P. K., Piao, S., Rogelj, J., Syampungani, S., Zaehle, S., and Zickfeld, K. (2021): Global Carbon and other Biogeochemical Cycles and Feedbacks. In: Climate Change 2021: The Physical Science Basis. Contribution of Working Group I to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change. Masson-Delmotte, V., Zhai, P., Pirani, A., Connors, S. L., Péan, C., Berger, S., Caud, N., Chen, Y., Goldfarb, L., Gomis, M. I., Huang, M., Leitzell, K., Lonnoy, E., Matthews, J. B. R., Maycock, T. K., Waterfield, T. Yelekçi, O., Yu, R., and Zhou, B. (Eds.), Cambridge University Press.
↑3, ↑6	Roberts, G., and Wooster, M. J. (2021): Global impact of landscape fire emissions on surface level PM2.5 concentrations, air quality exposure and population mortality. In Atmospheric Environment, 252, p. 118210. DOI: 10.1016/j. atmosenv.2021.118210.
↑7, ↑8	Qin, Y., Xiao, X., Wigneron, J.-P., Ciais, P., Brandt, M., Fan, L., Li, X., Crowell, S., Wu, X., Doughty, R., Zhang, Y., Liu, F., Sitch, S., and Moore, B. (2021): Carbon loss from forest degradation exceeds that from deforestation in the Brazilian Amazon. In Nature Climate Change, 11 (5), pp. 442–448. DOI: 10.1038/s41558-021-01026-5.

Browse insights in climate

5 Global climate action must be just 1 Stabilizing at 1.5°C warming is still possible, but immediate and drastic global action is required 2 Rapid growth in methane and nitrous oxide emissions put us on track for 2.7°C warming

3

Megafires—climate change forces fire extremes to reach new dimensions with extreme impacts

4 High-impact risks from climate tipping elements

10 Costs of climate change mitigation can be justified by the multiple immediate benefits to the health of humans and nature 6 Supporting household behavior changes is a crucial but often overlooked opportunity for climate action 7 Political challenges impede effectiveness of carbon pricing 8 Nature-based solutions are critical for the pathway to Paris—but look at the fine print 9 Building resilience of marine ecosystems is achievable by climate-adapted conservation and management, and global stewardship

Browse insights in climate

3

Megafires — Climate change forces fire extremes to reach new dimensions with extreme impacts

Climate tipping elements incur high-impact risks 4

5 Global climate action must be just Supporting household behaviour changes is a crucial but often overlooked opportunity for climate action 6

7 Political challenges impede effectiveness of carbon pricing Nature-based Solutions are critical for the pathway to Paris – but look at the fine print 8

9 Building resilience of marine ecosystems is achievable by climate-adapted conservation and management, and global stewardship Costs of climate change mitigation can be justified by the multiple immediate benefits to the health of humans and nature 10

1 Stabilizing at 1.5°C warming is still possible, but immediate and drastic global action is required Rapid growth in methane and nitrous oxide emissions put us on track for 2.7°C warming 2

10 New Insights in Climate Science

A year of climate-related science in review

Each year we consult researchers and carry out a horizon scan in fields related to climate change on what the latest findings and most important new emerging fields are. We summarize this in 10 important scientific insights, and the result has always been a rich and valuable scientific synthesis for policy and society at large, a testament to the ever-expanding and improving knowledge of our planetary climate systems and the interactions with the human world.

Download PDF

Extras

Definition of terms
References
Resources for media
Partners
Academic article

Acknowledgements

The full authoring team and other contributors are listed here. The making of this report has been led by Future Earth, The Earth League and the World Climate Research Programme (WCRP). We also gratefully acknowledge support from Arizona State University (ASU), GERICS Climate Service Center Germany (an institution of Helmholtz-Zentrum Hereon),

We acknowledge the work of the following individuals in their respective capacities:

Produced by: Future Earth, The Earth League, Azote, and the World Climate Research Programme
Website, graphics and publication design: Cultivate Communications, Azote

10 New Insights in Climate Science

A year of climate-related science in review

Each year we consult researchers and carry out a horizon scan in fields related to climate change on what the latest findings and most important new emerging fields are. We summarize this in 10 important scientific insights, and the result has always been a rich and valuable scientific synthesis for policy and society at large, a testament to the ever-expanding and improving knowledge of our planetary climate systems and the interactions with the human world.

Download PDF

Extras

Definition of Terms
References
Resources for media
Partners

Acknowledgements

The full authoring team and other contributors are listed here. The making of this report has been led by Future Earth, The Earth League and the World Climate Research Programme (WCRP). We also gratefully acknowledge support from Arizona State University (ASU), GERICS Climate Service Center Germany (an institution of Helmholtz-Zentrum Hereon),

We acknowledge the work of the following individuals in their respective capacities:

Produced by: Future Earth, The Earth League, Azote, and the World Climate Research Programme
Website, graphics and publication design: Cultivate Communications, Azote