Global emissions of carbon dioxide were at a record high in 2011 and are likely to take a similar jump in 2012, scientists reported Sunday -- the latest indication that efforts to limit such emissions are failing.
Emissions continue to grow so rapidly that an international goal of limiting the ultimate warming of the planet to 3.6 degrees Fahrenheit, established three years ago, is on the verge of becoming unattainable, said researchers affiliated with the Global Carbon Project.
Josep G. Canadell, a scientist in Australia who leads that tracking program, said Sunday in a statement that salvaging the goal, if it can be done at all, "requires an immediate, large and sustained global mitigation effort."
Yet nations around the world, despite a formal treaty pledging to limit warming -- and 20 years of negotiations aimed at putting it into effect -- have shown little appetite for the kinds of controls required to accomplish those stated aims.
Delegates from nearly 200 nations are meeting in Doha, Qatar, for the latest round of talks under the treaty, the U.N. Framework Convention on Climate Change. Their agenda is modest this year, with no new emissions targets and little progress expected on a protocol that is supposed to be concluded in 2015 and take effect in 2020.
Christiana Figueres, executive secretary of the climate convention, said the global talks are necessary but not sufficient to tackle the problem.
"We won't get an international agreement until enough domestic legislation and action are in place to begin to have an effect," she said in an interview. "Governments have to find ways in which action on the ground can be accelerated and taken to a higher level, because that is absolutely needed."
The new figures show that emissions are falling, slowly, in some of the most advanced countries, including the United States. That apparently reflects a combination of economic weakness, the transfer of some manufacturing to developing countries and conscious efforts to limit emissions, like the renewable power targets that many U.S. states have set. The boom in the natural gas supply from hydraulic fracturing is also a factor, since natural gas is supplanting coal at many power stations, leading to lower emissions.
But the decline of emissions in the developed countries is more than matched by continued growth in such developing countries as China and India, the new figures show. Coal, the dirtiest and most carbon-intensive fossil fuel, is growing the fastest, with coal-related emissions leaping more than 5 percent in 2011, compared with the previous year.
"If we're going to run the world on coal, we're in deep trouble," said Gregg H. Marland, a scientist at Appalachian State University who has tracked emissions for decades.
Overall, global emissions jumped 3 percent in 2011 and are expected to jump another 2.6 percent in 2012, researchers reported in two papers released by scientific journals on Sunday. It has become routine to set new emissions records each year, although the global economic crisis led to a brief decline in 2009.
The level of carbon dioxide, the most important heat-trapping gas, has increased about 41 percent since the beginning of the Industrial Revolution, and scientists fear it could double or triple before emissions are brought under control. The temperature of the planet has already increased about 1.5 degrees since 1850.
Further increases in carbon dioxide are likely to have a profound effect on climate, scientists say, leading to higher seas and greater coastal flooding, more intense weather disasters like droughts and heat waves, and an extreme acidification of the ocean. The earliest effects are already being seen, many experts believe, but they are projected to worsen.