Cities could put a massive dent in global warming if they got serious about cutting their carbon emissions, with or without the help of national governments.
That’s the word from a new report put out Tuesday by the C40 Cities Climate Leadership Group (C40), a network of major cities around the world, along with the Stockholm Environment Institute and Michael Bloomberg, the United Nation’s Special Envoy for Cities and Climate Change. The top line number from the paper is that city governments could cut the world’s annual greenhouse gas (GHG) emissions 3.7 billion tons in 2030 and 8 billion tons in 2050 on their own, with no national direction.
As the study notes, pledges by national governments so far to cut their emissions have focused on policies that cover multiple industrial sectors, like electricity and industrial production. “Their pledges and action plans have seldom considered or reflected the impact of urban climate actions,” the report said. “Cities also have unique and strong influence overs several policy levers — such as urban planning and public transportation — that may be less available to national actors.”
What this means is that emissions reductions from specifically city-based actions can be considered in addition to national reductions, rather than as a piece of the latter. And when the potential of the two is added together, the reduction is significant.
“The reality is that the work is going to be done in cities,” said Philadelphia Mayor Michael Nutter. “It will be done mostly by mayors. And then we will drive our respective nations’ national agendas around these issues.”
Furthermore, once we’ve emitted carbon pollution, it stays in the atmosphere for centuries. So annual emission rates don’t matter nearly as much as the total amount we emit, ever. And cumulatively, the urban actions outlined in the report could avoid 140 billion tons of GHGs by 2050. The latest work from the Intergovernmental Panel on Climate Change (IPCC) pegged the total amount the world can emit and still stay under 2°C of global temperature rise — the threshold beyond which scientist believe climate change will become truly dangerous — at 1,102 billion tons (1,000 billion metric tons). We’ve already emitted 585 billion tons, and under a business-as-usual scenario the IPCC thinks we’ll blow through the rest sometime in the early 2040s. So while cities can’t single-handedly save us, they could buy the world a fair amount of time.
Specifically, there are four things city governments can do. The biggest move would be improving building energy use through efficiency and weatherization retrofits, more energy-efficient lighting and appliances, and more rooftop solar to cut fossil energy use. Next, cities can move toward pedestrian and public-transit-reliant traffic through better urban planning. One quarter of the average product’s shipment occurs in urban areas, so the third thing cities could is improve the logistics and efficiency of rail shipments. Fourth, better waste systems and recycling operations can reduce the GHGs from garbage and landfills, and waste.
This insight is especially consequential for American politics. As David Roberts just pointed out at Grist, Republicans are likely to hold the House of Representatives for decades, where they can stymie national climate action. But a big reason they’ll be able to hold it is the intense clustering of liberal voters in cities — what’s come to be known as the “urban archipelago.” As a result, the governments of American cities are tilting increasingly liberal, putting them in a perfect political position to take maximum advantage of C40’s recommendations, even as the national legislature dithers on climate change.
Meanwhile, Zack Colman laid out at the Washington Examiner how the U.N. is stepping up efforts to coordinate emission-cutting efforts between city governments directly, bypassing the bigger and more cumbersome national governments. “Mayors are not waiting to take decisive action to combat global climate change,” added Eduardo Paes, the chairman of C40 and the mayor of Rio de Janeiro, in a statement.
“Leading mayors are setting the example for the rest of the world, and this research shows what could be achieved.”