Here’s How The World’s Biggest Cities Are Tackling Climate Change

International climate agreements may be stuck in the mud, but from bike-share programs to green building codes, cities around the world are leaping forward with innovative programs that reduce emissions.

Here’s How The World’s Biggest Cities Are Tackling Climate Change
[Image: Shanghai via Shutterstock]

Most national governments are completely paralyzed when it comes to addressing climate change. Some businesses are taking action, but for the most part, that leaves city and regional governments to fill the gap. Today, cities account for account for 70% of the world’s CO2 emissions and more than three quarters of the planet’s energy use. But here’s the good news: By and large, the world’s biggest cities are taking action.


That’s the major conclusion to be drawn from Climate Action in Megacities Volume 2.0, a 200-plus page report detailing the climate actions taken by member cities of the C40, a global climate leadership group. The first volume of the report came out in 2011, and things are looking up since then.

Fifty-nine out of 63 cities participated in the survey that led to this year’s report, which shows a trend of mayors carrying out more climate-friendly actions, such as launching bikeshare programs and stringent green building codes, across the board. “City governments tend to be far more nimble than their counterparts at national level,” former New York City Mayor Michael Bloomberg, president of the C40 Board, said a conference call with reporters. “Mayors don’t have time to debate politics. They have to deliver results.”

In this year’s survey, mayors reported that they have 8,000 climate actions in the works–nearly double the number reported in 2011 (though every action, no matter the size, counts equally). Some 41% of these actions are on a city-wide scale, compared to 14% in 2011. The world’s mayors, many of whom preside over coastal cities, know that they have a lot at stake. “There are lots of people out there debating whether climate change is actually an issue, but 98% of reported cities indicate climate change poses significant risk to their cities. It’s nearly unanimous. It isn’t a debate,” says Seth Schultz, C40’s director of research.

Mayors are focused on taking actions related to a handful of key issues, including climate adaptation, energy efficiency, transportation (this sector had the greatest increase in reported actions since 2011), and water. There’s a lot of evidence that cities are learning from each other, too. In 2011, six cities reported they had bikesharing schemes, and now, 36 cities have reported taking action. You might think that ideas drift over from wealthier cities that can access more capital and advanced technology, but that turns out not to be the case. Latin America was a bus rapid transit pioneer, for example, and now these systems are popping up in places like Chicago and New York City.

“We’re beginning to see the migration of ideas from south to north,” says Schultz.

High-tech solutions are becoming ubiquitous for wealthy, middle-income, and poor cities alike. Schultz gives the example of Rio de Janeiro, a median GDP city that has to contend with dangerous mudslides affecting people who live in favelas with little weather-ready infrastructure. The city created a command center in 2010, called the Rio Operations Center, that can forecast when various weather events will hit different parts of the city. It then rolled out a public announcement system so it can warn favela residents of impending weather events.


There are some regional differences in how cities choose to approach climate actions. “North America is dominated by projects and programs, and Asia is heavily dominated by policy. It has everything to do with government structure,” explains Schultz

If any of the actions taken by cities today actually mitigate economic damage from climate change, we’ll certainly know–the C40 member cities represent 21% of GDP. Their actions affect us all.

About the author

Ariel Schwartz is a Senior Editor at Co.Exist. She has contributed to SF Weekly, Popular Science, Inhabitat, Greenbiz, NBC Bay Area, GOOD Magazine and more.