Soot worse for global warming than thought.
Grains of soot deposited in snow have also caused about one-quarter of the observed rise in global surface temperature since 1880, suggests the model by James Hansen and Larissa Nazarenko. The pair examined how soot particles affect the atmosphere when they darken snow and ice.
The effect of soot on snow is unambiguous,” Hansen told New Scientist. “It causes a strong warming effect.”