650 million city residents will face water scarcity in 20501
1.6 billion city residents will face extreme heat by 20502
98 % of C40 cities have already faced severe climate threats3

About this sector

The consequences of climate change are already posing an existential threat worldwide. Adaptation is an essential part of climate action – as we work to keep global heating to 1.5°C, we must simultaneously prepare our cities for an increase of 3°C or more.

Cities have high population densities and are often situated at strategic yet vulnerable locations, putting them at higher risk for storms, floods, droughts and heatwaves. Due to climate change, these weather events are expected to occur more often and become more severe. Nearly 100% of C40 cities report that they have already faced severe climate threats that have jeopardized their economic and social prosperity.

More than two-thirds of the world’s largest cities are coastal delta cities vulnerable to rising sea levels as a result of climate change, exposing millions of people to the risk of extreme flooding and storms. The number of cities exposed to extreme temperatures will nearly triple over the next decades – by 2050, more than 970 cities will experience average summertime temperature highs of 35˚C (95°F). 

C40 works with cities to implement the adaptation and resilience measures they need to prevent the worst impacts of climate change and protect communities around the world. Our work touches on urban flooding, urban heat, water security, sea level rise and more, supporting cities by providing technical assistance, facilitating peer-to-peer exchange, joint projects and collaborating to create and implement global solutions.

Some examples of high-impact adaptation measures include:
  • Putting in place an early warning system and emergency response plan for extreme climate events
  • Implementing cool surfaces and expanding urban tree cover to combat urban heat
  • Improving river catchment management and implementing sustainable urban drainage systems to protect against flooding 
  • Preparing for sea level rise and coastal storms with nature-based and artificial barriers 
  • Improving water system efficiency, water treatment and recycling/reuse to ensure water security

Networks & Programmes

  1. The Future We Don’t Want, 2018 report by C40 and GCOM.
  2. Same as above.
  3. CDP, 2019.

Contact the team