Building resilience to protect communities from climate impacts
Extreme weather is putting people at risk and testing the limits of urban infrastructure
98% of C40 cities have already faced severe climate threats.[1] By 2050, up to 1.6 billion city residents will face extreme heat[2], more than 7.4 million people will be in areas at risk from flooding annually[3], and over 650 million will face water scarcity.[4]
These climate hazards are intensifying, with vulnerable communities bearing the heaviest burden and existing infrastructure not being able to cope. People living in C40 cities across the Global South are ten times more likely to be affected by flooding and drought than those in Global North cities.[5]
Cities have the power to protect residents through adaptation
C40 mayors are acting with urgency to protect at-risk communities. From flood warning systems to urban nature that reduces extreme heat and flooding, cities are helping protect residents and infrastructure from immediate and future climate risks. C40 supports cities to implement high-impact actions through technical assistance, guidance, and peer networks. Together, cities are demonstrating that building resilience protects vulnerable populations while creating healthier, more livable communities for all residents.
Creating adaptation solutions that protect vulnerable communities
Cities understand that effective climate adaptation requires solutions that prioritise those most at risk. Successful resilience strategies must:
Protect communities facing the greatest risks
Climate impacts hit hardest in neighbourhoods that have historically faced disinvestment and lack adequate infrastructure. Adaptation solutions must prioritise protection for vulnerable communities, particularly in low-income areas facing high flood, heat, and drought risk.
Act with urgency
With climate impacts intensifying now, cities need adaptation strategies that protect residents immediately while building long-term resilience. Early warning systems, emergency response plans, and cooling infrastructures deliver protection today.
Build on nature-based solutions
Cities are expanding urban tree cover, implementing sustainable drainage systems, and protecting green spaces. These efforts cool cities, manage stormwater, improve air quality, create healthier environments, and provide community amenities. Nature-based solutions are win-win investments that strengthen cities’ resilience to climate change while creating healthier, more equitable communities and supporting local biodiversity.
Create equitable outcomes
Adaptation investments must improve the quality of life for all residents, not accelerate displacement. Cities are ensuring that resilience projects create local jobs, improve public health, and enhance community wellbeing.
Prepare for future intensification
Today’s adaptation strategies must account for worsening climate impacts over the coming decades. Cities are planning for sea level rise, more frequent extreme heat, and intensifying droughts and floods to protect residents for generations.
This comprehensive approach is gaining momentum globally, with cities demonstrating that smart adaptation investments deliver returns that extend far beyond climate protection alone.
C40 Accelerators driving action on water, heat and nature
These C40 Accelerators help cities tackle urgent climate risks. Each brings together mayors committed to protecting residents through proven strategies, peer learning, and collective accountability.
C40 Water Safe Cities Accelerator
Learn about how C40 cities are committing to protect at-risk communities from flooding and drought through early warning systems, emergency response plans, and transformative water management solutions.
C40 Cool Cities Accelerator
See how C40 cities are protecting residents from extreme heat through cooling strategies and climate adaptation plans.
C40 Urban Nature Accelerator
Join cities committed to expanding nature in urban environments to build climate resilience and create healthier, more equitable communities.
Networks delivering water, heat and nature resilience
C40’s water, heat, and nature networks provide different entry points for cities to implement adaptation strategies, access technical support, and learn from peers facing similar climate risks.
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Questions about Water, Heat and Nature programmes?
Contact the water, heat and nature team at water@c40.org, heat@c40.org, or nature@c40.org for information on joining adaptation Accelerators and networks based on your city’s main climate risks.
Frequently asked questions
How can cities afford large-scale adaptation infrastructure?
Cities are using new ways to fund projects, such as green bonds, climate adaptation funds and international support. Generally, for USD 1 invested in adaptation, you get over USD 10.50 back in benefits over ten years. Many nature-based solutions also cost less than traditional concrete infrastructure and offer extra advantages.
How do cities ensure adaptation projects benefit vulnerable communities?
Cities prioritise adaptation in neighbourhoods facing the highest climate risks, involve community members in planning processes, create local jobs through adaptation projects, and track outcomes like improved public health and reduced displacement. C40’s frameworks help cities design community-centred resilience approaches.
What adaptation strategies are most effective for extreme heat?
Effective heat adaptation combines multiple approaches: expanding urban tree cover, implementing cool surfaces, establishing cooling centres, developing heat action plans with health sectors, and creating early warning systems. C40’s Heat Resilient Cities Tool and adaptation guides help cities design comprehensive heat strategies.
How do cities balance adaptation and mitigation priorities with limited budgets?
Many adaptation strategies also reduce emissions. Urban nature provides natural cooling, reducing air conditioning use and energy costs. Sustainable drainage reduces infrastructure maintenance costs, and water-efficient systems lower energy use. Cities are integrating adaptation and mitigation planning to maximise limited resources and deliver multiple benefits.