Carbon dioxide emissions from the power sector make up 25 percent of the all carbon emissions worldwide and 40 percent of carbon emissions in the United States, according to Carbon Monitoring for Action, or CARMA.

The new site, built by the Confronting Climate Change Initiative and the Center for Global Development, pinpoints local and far-away power plants and electric utilities on maps, listing the past, present and future emissions from each source. It also shows if the electricity comes from fossil fuels, hydro, nuclear or renewable power, and reveals planned plants that aren't even operating yet.

Interestingly, only 100 companies account for more than half of all the carbon dioxide emissions from all the power plants in the world.

While carbon dioxide is not the only dangerous greenhouse gas (methane is about 20 times stronger), this is a useful and easily accessible tool for digging into facts about how we power our lives. Spatially viewing the locations of current and future power plants shows that power plants could be much closer than we previously thought.