Ten Years of the Paris Agreement: The Present and Future of Extreme Heat

The report finds that global warming of 0.3°C since 2015 has already increased the annual average of hot days by 11 per country. While current emissions pledges have reduced projected warming from 4°C to 2.6°C, the latter would still result in an average of 57 additional hot days per year compared to today. Case studies of six major heat events show that some would have been nearly impossible without climate change, and all have increased in intensity and likelihood. The document argues that while heat early warning systems have expanded, adaptation finance and systemic urban and labor reforms are insufficient to meet the escalating risks.

• Since the signing of the Paris Agreement in 2015, the world has experienced an average of 11 more hot days per year. In 101 out of 207 countries, there has been an average increase of at least 10 additional hot days annually, with 10 countries seeing at least 30 more hot days per year.
• Current emissions reduction pledges, if fully implemented, project a warming of 2.6°C by approximately 2100. This scenario would lead to an average of 57 additional hot days per year compared to current levels, though this is significantly lower than the 114 additional hot days per year projected under a 4°C 'business as usual' baseline from 2015.
• Analysis of six extreme heat events across six continents reveals that three would have been 'nearly impossible' without climate change. Since 2015, these events have increased in likelihood by 1.4 to 9.5 times and in intensity by 0.2 to 0.6°C.
• Under a 2.6°C warming scenario, the six studied extreme heat events would be 1.5°C to 3°C hotter than in the present climate. In a 4°C scenario, these events would be 3°C to 6°C hotter and would become commonplace.
• Global heat adaptation has seen progress, with 104 countries now having extreme heat warnings and at least 47 countries possessing national heat-health/heat action plans (HHAPs/HAPs). However, coverage is uneven, with fewer systems in Africa, Latin America, and parts of Asia.
• Adaptation efforts are hindered by insufficient financing at the local level and a lack of transformative systemic changes. Current plans often focus on short-term health responses and neglect urban planning, labor protections, and the needs of vulnerable groups such as women, children, and people with disabilities.

APA

Arrighi, J., Dahl, K., Giguere, J., Keeping, T. R., Otto, F. E. L., Singh, R., Tannenbaum, A., Vahlberg, M., Barnes, C., Baumgart, N., Clarke, B., Kimutai, J., Marghidan, C. P., Philip, S., Pinto, I., Raju, E., Scholz, C., Vrkic, D., & Zachariah, M. (2025). Ten Years of the Paris Agreement: The Present and Future of Extreme Heat. Climate Central. https://assets.ctfassets.net/cxgxgstp8r5d/4Flrvo5gImUeQXlO82C3nm/33cc866aec9b1a93859fa01276b43e0e/-Report-_Ten_Years_of_the_Paris_Agreement__The_Present_and_Future_of_Extreme_Heat.pdf

Chicago

Arrighi, Julie, Kristina Dahl, Joseph Giguere, Theodore R. Keeping, Friederike E. L. Otto, Roop Singh, Arielle Tannenbaum, et al. Ten Years of the Paris Agreement: The Present and Future of Extreme Heat. Climate Central, 2025. https://assets.ctfassets.net/cxgxgstp8r5d/4Flrvo5gImUeQXlO82C3nm/33cc866aec9b1a93859fa01276b43e0e/-Report-_Ten_Years_of_the_Paris_Agreement__The_Present_and_Future_of_Extreme_Heat.pdf.

Wikipedia

{{cite report |last1=Arrighi |first1=Julie |last2=Dahl |first2=Kristina |last3=Giguere |first3=Joseph |last4=Keeping |first4=Theodore R. |last5=Otto |first5=Friederike E. L. |last6=Singh |first6=Roop |last7=Tannenbaum |first7=Arielle |last8=Vahlberg |first8=Maja |last9=Barnes |first9=Clair |display-authors=etal |title=Ten Years of the Paris Agreement: The Present and Future of Extreme Heat |publisher=Climate Central |date=2025 |url=https://assets.ctfassets.net/cxgxgstp8r5d/4Flrvo5gImUeQXlO82C3nm/33cc866aec9b1a93859fa01276b43e0e/-Report-_Ten_Years_of_the_Paris_Agreement__The_Present_and_Future_of_Extreme_Heat.pdf |access-date=23 October 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{arrighi2025ten, author = {Arrighi, Julie and Dahl, Kristina and Giguere, Joseph and Keeping, Theodore R. and Otto, Friederike E. L. and Singh, Roop and Tannenbaum, Arielle and Vahlberg, Maja and Barnes, Clair and Baumgart, Nick and Clarke, Ben and Kimutai, Joyce and Marghidan, Carolina Pereira and Philip, Sjoukje and Pinto, Izidine and Raju, Emmanuel and Scholz, Cornelia and Vrkic, Dora and Zachariah, Mariam}, title = {{Ten Years of the Paris Agreement: The Present and Future of Extreme Heat}}, institution = {Climate Central}, year = {2025}, url = {https://assets.ctfassets.net/cxgxgstp8r5d/4Flrvo5gImUeQXlO82C3nm/33cc866aec9b1a93859fa01276b43e0e/-Report-_Ten_Years_of_the_Paris_Agreement__The_Present_and_Future_of_Extreme_Heat.pdf}, urldate = {2026-10-23}, note = {Indexed by Climate Insights Directory} }