DAVOS, Switzerland — Xi Jinping, China’s president, galvanized supporters of the climate-change fight last year when he told an audience at the World Economic Forum that the effort “is a responsibility we must assume for future generations.”

This week, as they gather again in Davos for the annual global gabfest, world leaders continue to see China as a major force in that fight. Yet new figures show a complicating development: China’s emissions of climate-changing greenhouse gases may be rising again.

China — which already emits more carbon from burning fossil fuels than the United States and Europe combined — saw electricity use jump last year as its economy accelerated. Much of the extra demand was met by burning more coal, a particularly dirty fuel. Oil use has also risen as China has become the world’s largest car market, and so has natural gas consumption.

Experts say one annual increase doesn’t indicate China is returning to an era when its emissions grew by leaps and bounds. But the increase illustrates the challenges and compromises Beijing must juggle if it wants to stoke its economy and at the same time keep its environmental promises.