Extreme heat is worst climate hazard for world’s cities

• 4/5 of disclosing cities (80%) report facing a climate hazard to CDP in 2022
• 70% of disclosing cities expect hazards to be more intense in future
• Extreme heat was most reported climate hazard, facing half of cities (51%)
• Heat-related hazards also include drought (35%) and risk of wildfires (19%)

 Following the hottest month ever recorded in human history, fresh insights from CDP - the non-profit which runs the world’s environmental disclosure system for companies, cities, states and regions - shows that extreme heat is the most widespread climate hazard facing the world’s cities.

Four in five (80%) of the 1,090 cities that reported their environmental data through CDP-ICLEI Track in 2022 said they face significant climate hazards, with more than two thirds (70%) already being significantly impacted by them. Moreover, 70% of cities expect these hazards to be more intense in the future, while over half (58%) expect them to increase in frequency.

Just over half (51%) of the reporting cities (557 cities) reported extreme heat as a hazard1, making it the most widely reported climate hazard facing the world’s cities. Other significant heat-related hazards reported by cities to CDP-ICLEI Track include drought (35% of cities) and the risk of wildfires (19%).

As seen in July of this year, when the earth saw its hottest month on record - and in an estimated 120,000 years - and since then, when wildfires ravaged parts of the planet from Hawaii to Portugal to China, extreme heat is affecting every corner of the globe. Of cities that reported climate hazards, 81% (179 cities) in North America reported extreme heat as a climate hazard, followed by 79% (153 cities) in Europe and the UK, 58% (86 cities) in Asia Pacific, 49% (31 cities) in Africa and the Middle East, and 43% (108 cities) in Latin America. These include New York (USA), Vancouver (Canada), São Paolo (Brazil), Athens (Greece), London (UK), Tel Aviv (Israel), Abuja (Nigeria), Delhi (India) and Melbourne (Australia). It is important to note, however, that the number of cities in Africa, the Middle East and certain countries in Asia - areas particularly affected by extreme heat - reporting data through CDP-ICLEI Track remains relatively low.

CDP’s analysis also examines the stark impact of extreme heat on the world’s population, finding that the elderly (reported by 88% of cities), low-income households (67%), children and youth (63%) and marginalised communities (45%) are the groups most affected by it. Meanwhile, the analysis shows that for 143 cities, almost their entire population (90-100% of a city’s population) is affected by extreme heat.

Maia Kutner, CDP Global Director for Cities, States and Regions, said:

“The last few weeks have given us an uncomfortable insight into what the future holds for our planet through the lens of just one of many climate hazards, extreme heat. Fire after fire after fire devouring homes, livelihoods and nature from Hawaii to China; the single hottest month ever recorded in human history; and the warmest reported ocean temperature. All of which, in years to come, will seem unremarkable.

“The consequences of the actions and policies that have led us to the point where the world is literally on fire are as clear as the blankets of smoke seen from space. There is good news though - there is still time to act to reduce emissions, switch to clean energy, make our cities resilient and protect people and nature, but national and local governments must focus and move very fast.

“Reporting environmental data through CDP-ICLEI Track is a city’s first step on the road to that meaningful and tangible climate action, as what gets measured, then gets managed. We urge all cities, large or small, to do the ‘measuring’ now, so they can get on with the ‘managing’ to build the sustainable future we, and our planet, so desperately need.”

1Extreme heat includes the following hazards: extreme heat, heat stress, extreme hot days and urban heat island effect.