Report•October 16, 2025
Ten Years of the Paris Agreement: The Present and Future of Extreme Heat
Read the full report: Ten Years of the Paris Agreement: The Present and Future of Extreme Heat
This joint report from Climate Central and World Weather Attribution conducts a global analysis of how extreme heat has changed since the signing of the 2015 Paris Agreement and how current pledges to reduce emissions will shape the future of extreme heat on Earth.
The analysis explores how heat experienced locally — through hot days and heat waves — is influenced by global warming. Heat contributes to an estimated 500,000 deaths worldwide each year, making it the deadliest form of extreme weather. The future frequency and intensity of this threat depends mostly on global carbon emissions levels in the coming decades, which the Paris Agreement goal aims to curb.
This analysis describes heat conditions at four levels of global warming compared with pre-industrial temperatures:
Global warming level | Description |
|---|---|
1°C | Amount of warming that had occurred when the Paris Agreement was signed (2015) |
1.3°C | Amount of warming that has occurred through the present day (2025) |
2.6°C | Amount of warming projected by ~2100 if Paris Agreement emissions reduction pledges are fully carried out (and if enabling policies are enacted and sustained) |
4°C | Amount of warming that was employed as the baseline warming expected by ~2100 in the 2015 emissions gap report, prior to the signing of the Paris Agreement |
Key Messages
The Paris Agreement provides an important legal and political framework toward a safer and fairer world. Projected warming this century has dropped from about 4°C in 2015 to 2.6°C today — if current emissions reduction pledges are fully implemented.
However, 2.6°C of warming would still lead to a dangerously hot planet. Every fraction of a degree of warming results in more frequent and intense heat. The world now experiences an average of 11 more hot days per year with the additional 0.3°C of warming since 2015. In a 2.6°C world, that increases to 57 extra hot days per year compared to now; at 4°C, that rises to an additional 114 hot days per year.
Case studies in this report confirm that extreme heat waves have already become more likely since 2015. Three of the six events studied would have been nearly impossible without climate change, and two of those are now about 10 times more likely to occur in 2025 than in 2015.
Since 2015, heat early warning systems and action plans have expanded worldwide, but progress is insufficient and is slowed by limited financing for heat adaptation at the local level.
The costs of inaction on extreme heat are rising faster than adaptation. Health, labor, and infrastructure are under strain, adaptation finance is insufficient, and the most vulnerable risk being left behind unprepared.
The expected warming this century is still far above the Paris goals of keeping warming to 1.5°C and well below 2°C. The highest possible ambition as set out in the Paris Agreement to achieve deep, rapid, and sustained emissions reductions is urgently needed.
Data
Download data for all 207 countries and territories included in the analysis.
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Major funding provided by the Bezos Earth Fund