How Can Cities Reach Their Climate Goals?

Abstract

A decade ago, the global network of “megacities” known as C40—so named for the forty cities that founded it in 2005—released a report titled “Why Cities Are the Solution to Global Climate Change.”1 Seoul, Mumbai, Paris, Cape Town, and other cities have won awards for their leadership on climate, and U.S. cities are, C40 suggests, doing more on climate than major cities elsewhere.2 In 2019, the mayor’s office of New York City (NYC) stated that it was “leading the fight against climate change” and would achieve carbon neutrality by 2050, and pledged to “electrify the city with 100 percent clean electricity sources.”3 Today, hundreds of cities have adopted ambitious climate targets, committing to reduce fossil-fuel dependency, use more renewable energy, green their transport systems, and be more energy efficient.4 Networks of mayors and other municipal officials committed to climate action have proliferated.5 The fact that cities have positioned themselves as climate leaders is a big deal. Cities occupy just 2 percent of the Earth’s surface, but they account for more than 70 percent of CO2 emissions.6 So if cities can take the lead in reducing their emissions, then who is to argue? The benefits to the climate could be enormous. Of the many targets adopted by cities, “100 percent renewable energy” is perhaps the most important from a climate perspective. Improved energy efficiency is also essential, but it is the electrification of transport, heating, and cooling in buildings, among other things, that will be make or break for cities. By the end of 2019, more than 230 cities globally had adopted targets for 100 percent renewable electricity.7 Of the ninety-seven “megacities” currently in the C40 network, twenty-four have committed to achieving 100 percent renewable electricity by 2030.8 Many smaller cities have done the same. The Sierra Club recently reported that 170 U.S. cities have made the 100 percent commitment.9