Speed Reads

Climate change

Scientists: Global greenhouse gas emissions up in 2013

In 2013, global emissions of greenhouse gases rose 2.3 percent, scientists reported Sunday in the journal Nature Geoscience.

The numbers were reported by the Global Carbon Project tracking initiative, and released prior to a United Nations summit on Tuesday that will attempt to tackle climate change. Scientists say there's no sign that U.N. member nations will agree to more ambitious efforts to curtail emissions, but they insist that changes need to be made — and soon.

"You can no longer have some countries go first and others come in later, because there is no more time," Glen P. Peters, a scientist with the Center for International Climate and Environmental Research, told The New York Times. "It needs to be all hands on deck now."

In the United States, emissions rose 2.9 percent, thanks to greater use of coal, after declining in recent years due to increased burning of natural gas in power generation. Overall global emissions growth was slightly slower than the average annual rate of 2.5 percent over the past 10 years, thanks in part to an economic slowdown in China. China is the world's largest source of emissions, at 10 billion tons a year of carbon dioxide from burning fossil fuels and manufacturing cement.