“Historically, people have associated pollution and environmental damage with cities and, as far as climate warming goes, it is true that urban areas have large energy consumption,” according to Dodman. “But many emissions come from rural areas, and methane is a far more potent greenhouse gas than carbon dioxide.”
In his study, published in the journal Environment & Urbanization, Dodman compared greenhouse-gas emissions in 12 large cities around the world with the average emissions of their respective countries. On average, he found, city dwellers emit fewer greenhouse gases than the average for their country.
“There are density-related advantages for both travel and heating” in cities, says Dodman. “When you have a critical mass of people like in London or New York, public transport becomes a feasible option for many, while people in more rural areas rely more on cars. And a flat that is surrounded by others is more efficient to heat than a free-standing house.”
In per-capita emissions terms, Washington was found to be the most environmentally unfriendly city of those studied. But despite its residents’ average carbon footprint being almost three times that of other large cities in developed nations, Washington’s inhabitants were found to emit only 82.4% of the United States’ average.
Dodman says that other wealthy cities – including New York, Tokyo, London and Seoul — also produced less greenhouse gas per capita than did their countries as a whole. In contrast, Beijing and Shanghai emit more than double China’s national average. According to Dodman, this most likely results from their thriving manufacturing industries and boundaries that encompass rural areas.
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