C200: Cities as a Solution to Climate Change

The task of averting the worst impacts of climate change is unbelievably daunting. Global greenhouse gas emissions must peak this decade and decline rapidly—to less than 1 ton CO2e per capita—within just a few decades.

Cities are on the front lines of this challenge.  Nearly 70% of the world’s population is expected to live in cities by 2050.   The way cities are built – and rebuilt – has profound implications for their contribution to—and resilience against—climate change.

For example, dense, lively, pedestrian- and transit-oriented cities can help us move around with much lower greenhouse gas emissions: as low (or even below) 1 ton CO₂e per capita (see graph below), compared to a national U.S. average of 4 tons CO₂e per person for ground transportation (largely cars).

Yet the full annual emissions footprint of a U.S. resident averages about 29 tons CO₂e/capita, including significant emissions from sources well beyond the city border, such as air travel and emissions needed to make the food we eat and products we use.   Even a dense, vibrant—heck, even car-free city—couldn’t (on its own) avoid these other emissions.

Cities are complex, wonderful systems that, by their very nature, can help orient us to low-GHG lifestyles, particularly for daily transportation.  Once we get our cities on that path, next up: can our cities, with their convergence of people and capital, also transform the rest of the economy?

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Peter Erickson is a staff scientist in the Seattle office of the Stockholm Environment Institute.