The tiny black particles released into the atmosphere by burning fuels are far more powerful agents of global warming than had previously been estimated, some of the world’s most prominent atmospheric scientists reported in a study issued on Tuesday.

These particles, which are known as black carbon and are the major component of soot, are the second most important contributor to global warming, behind only carbon dioxide, wrote the 31 authors of the study, published online by The Journal of Geophysical Research-Atmospheres.

The new estimate of black carbon’s heat-trapping power is about double the one made in the last major report by the United Nations’ Intergovernmental Panel on Climate Change, in 2007. And the researchers said that if indirect warming effects of the particles are factored in, they may be trapping heat at almost three times the previously estimated rate.

The new calculation adds urgency to efforts to curb the production of black carbon, which is released primarily by diesel engines in the industrialized world and by primitive cook stoves and kerosene lamps in poorer nations. Natural phenomena like forest fires also produce it.