On June 8,2018, the Eco-Business online magazine published an article entitled: “There’s an easy way for national governments to help cities act on climate change, give them data”. The Development of “emission inventories”, measuring how much greenhouse gases a city emits and identifying where they come from, is the first step to creating a city climate action plan. Yet most cities lack the financial and technical resources to collect this kind of data. The Global Protocol for Community-scale Greenhouse Gas Emission Inventories, the GPC, is an accounting standard that guides cities in how to consistently and credibly measure and report their emissions. It details the kinds of data cities should collect. The GPC outlines a methodological approach to downscale national or regional statistics to the city-level. With this data in hand and the GPC, experts can start completing their greenhouse gas inventory and climate action plans.