Worldwide carbon dioxide emissions continue to increase, new research shows

The world's emissions of heat-trapping carbon dioxide are continuing to rise and the pace of increase was greater in 2011 than in 2010.

New research released Sunday indicates that nations released about 9.5 billion metric tons of carbon dioxide last year, with the greenhouse gas reaching the highest level of concentration in the atmosphere on record.

The rate of increase in carbon dioxide emissions each year has averaged 3.1 percent between 2000-2011, according to the annual report released by the Global Carbon Project.

That pace of growth, if maintained throughout this century, would lead to an average surface air and water temperature increase worldwide of more than five degrees Celsius by the year 2100.

A temperature increase of that magnitude would far exceed the limit of a two degree Celsius increase agreed to by the planet's nations at the 2009 United Nations Climate Change Conference in Copenhagen.

"Each year of increased emissions makes a two degree target harder to achieve," Glen Peters, the lead author of the study and a senior research fellow at Norway's Center for International Climate and Environmental Research. "The only feasible way to keep below two degrees is global reductions in emissions and this can only happen if the top emitters in the developed and developing world have deep and sustained mitigation."

That is not occurring, at least in the developing world. Sunday's report indicates that carbon dioxide emissions in China and India continue to increase at a rapid pace.

Chinese carbon dioxide pollution of the atmosphere rose by 9.9 percent in 2011, a slight decrease from the 10.4 percent rate of increase in 2010, while India's contribution to the atmosphere's build-up of carbon dioxide increased by 7.5 percent last year.

Overall, developing countries contributed 58 percent of global carbon dioxide emissions in 2011. That's a huge increase from 1990, when they contributed only 35 percent.

China was responsible for 28 percent of the planet's carbon dioxide emissions last year, with sources in India  contributing seven percent.

Emissions in the United States and the European Community are still rising, but at a slower pace. The U.S. accounted for 16 percent of worldwide carbon dioxide emissions in 2011, with the EC's contribution at 11 percent.

An additional 2.6 percent increase in worldwide emissions is expected this year, with carbon dioxide emissions reaching a level 58 percent higher than they were in 1990.

"Limiting global climate change and all of its consequences is going to require aggressive actions to limit the use of fossil fuels," Gregg H. Marland, a research professor at Appalachian State University's Research Institute for Environment, Energy, and Economics and one of the scientists involved in the ongoing research documented in the paper released Sunday, said in a statement.

The paper appears in Nature Climate Change.