As nations lag on climate action, their cities are stepping up. Here’s proof.

Your city is probably fighting climate change in more ways than you realize. Perhaps your mayor is on a mission to plant more trees, or they’ve set efficiency standards for buildings, requiring better windows and insulation. Maybe they’ve even electrified your public transportation, reducing both greenhouse gas emissions and air pollution.
Ten years after the Paris Agreement, nations are still nowhere near ambitious enough in their commitments to reduce emissions and avoid the worst consequences of climate change. More than that, they haven’t shown enough follow-through on the goals they did set. Instead, it’s been cities and other local governments that have taken the lead. According to a new report by the Global Covenant of Mayors for Climate and Energy and C40 — a global network of nearly 100 mayors prioritizing climate action, collectively representing nearly 600 million people — three quarters of the cities in the latter group are slashing their per capita emissions faster than their national governments. As global greenhouse gas emissions continue to rise, per capita emissions across C40’s cities fell 7.5 percent on average between 2015 and 2024.
“The untold story is that cities and local leaders really mobilized in a big way in Paris, but also in the decade since,” said Asif Nawaz Shah, co-author of the report and the head of impact and global partnerships at C40 and the Global Covenant of Mayors for Climate and Energy. “It’s where the action happens, and it’s also where people are suffering the impacts the most.”
Cities are adapting because they’re experiencing especially acute effects of climate change as their populations rapidly grow. They’re getting much hotter than surrounding rural areas due to the urban heat island effect, in which the built environment soaks up the sun’s energy during the day and slowly releases it at night. Because a warmer atmosphere holds more moisture, they’re suffering increasingly catastrophic flooding as rains overwhelm sewer systems designed for the climate of yesteryear. And coastal cities have to deal with sea-level rise, in addition to fiercer tropical storms.
Mayors can more quickly deploy fixes than national governments can, climate experts say. Cities are less politically divided, for instance, and officials are more in tune with the immediate needs of their residents than a faraway federal government is. “I think that’s part of what makes it easier for mayors to make the case for climate action, because they’re not just addressing a concept that can seem a little abstract,” Shah said. “They’re addressing it through the lens of what people’s lived realities and experiences are.”
By making their cities more liveable, mayors also make them more sustainable, especially when it comes to walkability, bikeability, and vehicle transportation. The report notes that Melbourne, Australia is on a quest to create “20-minute neighborhoods,” in which people can reach most of their daily needs — work, schools, grocery stores — within a 20-minute return walk from home. Over in Shenzhen, China, officials have electrified 16,000 buses, reducing annual CO2 emissions by over 200,000 tons.
And by literally greening their cities, mayors solve a bunch of their citizens’ problems at once. In Quezon City in the Philippines, the government turned unused land into 337 gardens and 10 model farms, while training more than 4,000 urban farmers. The report also notes that Freetown, Sierra Leone, planted more than 550,000 trees, creating more than 600 jobs. In addition to significantly reducing urban temperatures, these green spaces also mitigate flooding by soaking up rainwater. “It is becoming clear, I think, to a lot of municipalities that this type of action will be absolutely essential,” said Dan Jasper, senior policy advisor at the climate solutions group Project Drawdown, which wasn’t involved in the report. “It’s not just about being uncomfortable. This is about protecting people’s lives.”
Mayors are also improving access to clean energy and more efficient appliances. The report notes that Buenos Aires, Argentina installed solar panels on more than 100 schools, while Qab Elias, Lebanon went a step further by partnering with a private supplier to allow half of its homes to install solar.
It’s not as if all nations are leaving cities to their own devices, though. The Coalition for High Ambition Multilevel Partnerships, for instance, is an initiative signed by more than 70 national governments to help cities, states, and regions with planning and financing climate action. “I find it very heartening, to be honest, that cities really are taking the lead,” Jasper said. “I think they’re going above and beyond in some respects, about planning for the future, as well as actually implementing some of the things that the federal governments have signed on to.”
Still, not nearly enough funding is flowing to cities and other local governments to do all the climate action they need. Unlike national governments, they can’t print their own money, so they’re strictly limited by their budgets. Conservative governments like the Trump administration are also slashing funds for climate action. Last year, 611 cities disclosed 2,500 projects worth $179 billion, but urban climate finance has to rise to $4.5 trillion each year by 2030, the report says. These are not donations but investments with returns: Spending money now to adapt to climate change means spending less on disaster recovery and health care in the future. “It’s not a call for handouts or for freebies,” Shah said. “It’s a call for genuine long-term investment that will yield results to protect citizens and livelihoods.