A Small Number of People Are Causing a Huge Share of Our Greenhouse Emissions

You probably don't need a sophisticated climate model to tell you that a compact, car-free apartment in the city has a smaller carbon footprint than a 3,000 square-foot single-family house in the suburbs. But add all of those big, far-flung homes together, and their cumulative impact starts to look really disproportionate. In many metropolitan areas, this means that a narrow slice of households are responsible for a vastly larger share of the region's greenhouse gas emissions.

Just how much larger are we talking? An interesting new study out of Switzerland, published in the American Chemical Society's journal Environmental Science & Technology, looked at this question in a single town there. Researchers at ETH-Zurich developed a model using census data for the life-cycle assessment of housing and local transportation consumption in the town of Wattwil, home to 3,238 households. Twenty-one percent of the households there, the researchers calculated, were responsible for 50 percent of the region's housing and mobility-related emissions.