By Lizzie Wade, Science
December 8, 2014

Cities are not just where 3.5 billion of us live—they are where more than  half of humanity uses electricity, drives cars, and throws out garbage, among myriad other activities that emit greenhouse gases. Now, a global coalition has released the first standardized method for measuring and reporting a given city’s greenhouse gas emissions. Called the Global Protocol for Community-Scale Greenhouse Gas Emission Inventories (GPC), the new standards were unveiled today at the United Nations’ ongoing climate negotiations in Lima.

Continue reading on sciencemag.org.