In its annual World Energy Outlook report, the Paris-based IEA said top carbon polluter China had the largest emissions growth last year, up 300 million tons, or 3.8 percent, from 2011. Still, the increase was among the lowest seen in a decade as China continues to invest in renewable energy and energy efficiency.

U.S. emissions dropped 200 million tons, or 3.8 percent, in part due to a switch in power generation from coal to gas, while Europe’s emissions declined by 50 million tons, or 1.4 percent, the IEA said.

The agency said the energy sector accounts for about two-thirds of global emissions of CO2 and other greenhouse gases, which scientists say are fueling climate change.

Global climate talks are aimed at keeping the temperature rise below 2 degrees Celsius (3.6 F) compared with pre-industrial levels. The IEA found the world’s on track for an increase of 3.6-5.3 C (6.5-9.5 F).

“Climate change has quite frankly slipped to the back burner of policy priorities. But the problem is not going away – quite the opposite,” said IEA Executive Director Maria van der Hoeven.

Climate scientists have warned that the global temperature rise could have catastrophic consequences such as flooding of coastal cities and island nations, disruptions to agriculture and drinking water, and the spread of diseases and the extinction of species.