TheCityFix reported on a new study today that dissects the relationship between cities and greenhouse gas emissions – and the results are a bit humbling for global city-dwellers. Or at least the more affluent, sprawly ones.
Cities and Greenhouse Gas Emissions, researched by World Bank staff and Canadian academics, went beyond just per capita emissions and looked at total emissions. That, combined with also considering emissions from the production of what city residents consume, results in about 80% of the world’s share (though a little over half of the global population is actually urban). Like any alarming new climate stats, once you pick apart a number generalized to the whole world the picture is more nuanced and less surprising. Affluent urbanites produce a larger share of emissions, denser neighborhoods are more efficient than less dense ones. The chart below is an example – unsurprisingly the U.S. is the biggest, fattest emissions blob:
CO2 emissions per capita, 1967-2005, from Cities and Greenhouse Gas Emissions, p. 16
But that’s exactly the point the report is trying to make – rather than take it at face value that cities by nature are more efficient, policymakers and planners need to look at the nuanced context of where they’re operating when doing emissions inventories and designing climate strategies. In other words, disaggregate, disaggregate, disaggregate.
The irony is that obviously with climate change comes greater vulnerability to coastal cities, but according to forthcoming work by the Asian Development Bank the impacts of how climate change will force migration to urban areas that are safer is sorely neglected and likely to accelerate. So by that logic cities create most of the world’s carbon emissions, the effects of which will cause more people to move to cities, resulting in greater urban emissions…and so on.
Maybe that’s a bit fatalistic, but on a more hopeful note with greater density and better transit options cities do end up having lower per capita emissions. Cities are also at the forefront for taking action on climate change, perhaps because residents and businesses benefit directly from energy efficiency and better transportation. Cities form for reasons of efficiency – good planning and policies to mitigate greenhouse gas emissions will also have a proportionately large impact to cool down our hot, crowded cities.