Looking back on it, 2019 was the year the “climate emergency” was declared, and while many countries have responded to the call, the movement to put out the fire has, in many ways, been led by cities. Over 1,200 local governments around the world have now signed the Climate Emergency Declaration. And in October, many of the world’s most influential mayors announced their support for a global Green New Deal. These mayors are members of C40, a network of 94 large cities—Paris, Los Angeles, Shanghai, Lagos, to name a few—committed to meeting the goals of the Paris Agreement of limiting global warming to 1.5 degrees Celsius over preindustrial levels and reducing global greenhouse gas emissions by 50 percent by 2030.

That declaration didn’t just reaffirm these cities’ efforts to fight climate change. It placed social and economic justice at the heart of that work, pledging to help alleviate poverty and calling for an inclusive and “just” transition for the populations most affected by climate change.

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This was a nonbinding statement but nonetheless reflective of a profound shift in the urban narrative around climate change that no longer sees environmental sustainability as disconnected from human rights. “The mayors of the 94 most influential cities in the world are increasingly seeing climate and equity issues as connected," says David Miller, C40’s North America director. While action is to a large degree dependent on national policies, cities can do plenty. By implementing low-carbon measures, they could cut urban emissions in key sectors by almost 90 percent by 2050, according to the Coalition for Urban Transitions.

Of the 184 countries that have published climate goals tied to their participation in the Paris Agreement, only 20 percent have been deemed sufficient to reach the 1.5 degree target, according to a report from the Universal Ecological Fund. By contrast, C40 cities have drafted climate action plans that are as ambitious, if not more so, than the accord’s targets. Copenhagen is working to become the world’s first carbon-neutral city by 2025. New York City aims to reduce its emissions by 80 percent in the next 30 years. Toronto wants all vehicles riding within its city limits to use low-carbon energy by 2050.

“We've spent, collectively, a really significant amount of time telling people what to be worried about, but we haven't spent enough time talking about the kind of future people want.” C40 North America director David Miller

Cities, after all, are on the front line of climate change. They’re responsible for 75 percent of global carbon emissions, and their leaders are well positioned to tackle the problem, says Leah Lazer, a research analyst at the Coalition for Urban Transitions, a cross-sector initiative that helps national governments drive progress toward sustainable cities. “City governments are closer to their citizens and their experience and can more easily tap into public sentiment in a way that can be harder for national governments,” she says. They’re also able to act faster and innovate on climate change mitigation at a smaller scale.

Many of those actions focus on transportation. London wants its taxis and ride-share vehicles to go emission-free by 2033. Medellín is piloting zero-emission zones through its downtown core. Oslo is working toward making its public transport entirely emission-free by 2028. Seattle is considering setting up congestion pricing, and New York City is moving forward with its own road pricing scheme.

But C40 mayors aren’t contenting themselves with ambitious targets. They now say planning should take into account how urban planning and climate intersect with well-being. The group’s chair, Los Angeles mayor Eric Garcetti, says member cities will now systematically engage civil society groups, business communities, and labor unions in climate planning. His plan to decarbonize the ports of Los Angeles and Long Beach acknowledges that emissions from diesel-fueled ships and vehicles primarily impact low-income communities of color nearby, whose residents suffer higher rates of cancer and respiratory diseases.