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The Boston Globe

Nation

Project to track carbon footprints of big cities

LA, Paris are test cities for sensors

LOS ANGELES — Every time Los Angeles exhales, odd-looking gadgets anchored in the mountains above the city trace the invisible puffs of carbon dioxide, methane, and other greenhouse gases that waft skyward.

Halfway around the globe, similar contraptions atop the Eiffel Tower and elsewhere around Paris keep a pulse on emissions from smokestacks and automobile tailpipes. And there is talk of outfitting Sao Paulo with sensors that sniff the byproducts of burning fossil fuels.

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