A new NASA study has found that an important counter-balance to the warming of our planet by greenhouse gases – sunlight blocked by dust, pollution and other aerosol particles – appears to have lost ground. The thinning of Earth’s "sunscreen" of aerosols since the early 1990s could have given an extra push to the rise in global surface temperatures. The finding, published in the March 16 issue of Science, may lead to an improved understanding of recent climate change.

URL: http://earthobservatory.nasa.gov/Newsroom/NasaNews/2007/2007031524529.html