U.S. greenhouse gas emissions rose 2 percent in 2013, with power plants contributing the most heat-trapping gases that scientists blame for driving climate change.

The bump reflects a number of factors, the Environmental Protection Agency said Thursday in its Greenhouse Gas Inventory report, such as people driving more and an uptick in industrial activity as the economy improved following the 2008 recession. A key driver was the increasing use of coal in 2013 in the power sector, which accounted for 31 percent of emissions, after years of decline.