Emissions continue to grow so rapidly that an international goal of limiting the ultimate warming of the planet to 3.6 degrees, established three years ago, is on the verge of becoming unattainable, said researchers affiliated with the Global Carbon Project.

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 American 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 developing countries like China and India, the new figures show. Coal, the dirtiest and most carbon-intensive fossil fuel, is growing 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,” saidGregg H. Marland, a scientist at Appalachian State University who has tracked emissions for decades.

The level of carbon dioxide, the most important heat-trapping gas in the atmosphere, 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. Many experts believe the effects are already being seen, but they are projected to worsen.