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.
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,
n 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.