New study shows billions of urban citizens at risk of climate-related impacts by 2050

New research by Acclimatise, C40, the Urban Climate Change Research Network (UCCRN), and Global Covenant of Mayors for Climate & Energy reveals number of cities and citizens threatened by direct and indirect climate hazards if global greenhouse gas emissions continue unchecked. Bold climate action by cities is key to prevent 1.6 billion people being exposed to extreme heat, 800 million to coastal flooding, and 650 million to droughts. 

Billions of people in thousands of cities around the world will be at risk from climate-related heatwaves, drought, flooding, food shortages, blackouts and social inequality by mid-century without bold and urgent action to reduce greenhouse gas emissions. Fortunately, cities around the world are delivering bold climate solutions to avert these outcomes and create a healthier, safer, more equal and prosperous future for all urban citizens.

This new research predicts how many urban residents will face potentially devastating heat waves, flooding and droughts by 2050 if global warming continues on its current trajectory. The Future We Don’t Want – How climate change could impact the world’s greatest cities also looks at indirect climate impacts and estimates how climate change under a ‘business-as-usual scenario’ will impact urban food security and energy systems as well as the urban poor, who are most vulnerable to climate change.

Headline findings include that, by 2050

• 1.6 billion people living in over 970 cities, will be regularly exposed to extreme high temperatures.
• Over 800 million people, living in 570 cities, will be vulnerable to sea level rise and coastal flooding.
• 650 million people, in over 500 cities, are at risk of water shortages due to climate change.
• 2.5 billion people will be living in over 1,600 cities where national food supply is threatened by climate change.
• The power supply of 470 million people, in over 230 cities, will be vulnerable to sea level rise.
• 215 million poor urban residents, living in slum areas in over 490 cities, will face increasing climate risks.

The Future We Don’t Want also contains concrete examples of bold climate solutions that cities are delivering, which, if adopted at-scale, could help prevent the worst impacts of climate change. The research was launched at the Adaptation Futures conference in Cape Town, where representatives of cities around the world are sharing ideas on how to prepare and adapt their cities for the effects of climate change.

“For decades, scientists have been warning of the risks that climate change will pose from increasing global temperatures, rising sea levels, growing inequality and water, food and energy shortages. Now we have the clearest possible evidence of just what these impacts will mean for the citizens of the world’s cities, said Mark Watts, Executive Director C40 Cities. “This is the future that nobody wants. Our research should serve as a wake-up call on just how urgently we need to be delivering bold climate action.”

“For most C40 cities, the impacts of climate change are not a far-off threat. From Cape Town to Houston, Mayors are seeing severe droughts, storms, fires and more,” said Antha Williams, Head of Environmental Programs at Bloomberg Philanthropies and C40 Board Member, “As this report shows, C40 mayors are on the front line of climate change, and the actions they take today–to use less energy in buildings, transition to clean transportation and reduce waste—are necessary to ensure prosperity and safety for their citizens.”

“Climate change is already happening, and the world’s great cities are feeling the impact. Cape Town is facing an unprecedented drought, but thanks to the efforts of our citizens to adapt, we have averted Day Zero, when we would have had to switch off most taps,” said Patricia de Lille, Executive Mayor of Cape Town and Global Covenant of Mayors for Climate & Energy Board Member. “The lessons from Cape Town, and from this important new research is that every city must invest today in the infrastructure and policies that will protect citizens from the future effects of our changing global climate.”

City climate solutions featured in the report include:

• Extreme heat: Seoul has planted 16 million trees and expanded its green space by 3.5 million m2. The city has also set up shaded cooling centres for those unable to access air conditioning.
• Flooding: New York City is improving coastal flood mapping, strengthening coastal defences and building smaller, strategically placed local storm surge barriers around the city.
• Drought: São Paulo has set up reward schemes to incentivise citizens to use less water, whilst investing in the city’s pipeline system to reduce water leakage.
• Urban food security: Paris plans to establish 33 hectares of urban agriculture within the city’s boundaries by 2020. By 2050, 25 percent of the city’s food supply will be produced in the Île-de-France region
• Energy Supply: London is improving drainage infrastructure to ensure key infrastructure can withstand heavy flooding, whilst also encouraging decentralised energy supply to reduce the risk of blackouts if any one power source is damaged.
• Extreme heat & poverty: Lima’s Barrio Mío programme created a poverty map of the city helping policy makers to focus resources on the most vulnerable and under-served areas where people are most exposed to heat risks.