No Silver LiningsA giant, polluting, climate-tampering cloud stalks the U.S.
NASA's Aqua satellite imaged this brown shadow of dust, soot, smog and other pollutants floating on the prevailing winds over the Sea of Japan in 2005. Such plumes are lofted into the sky by sandstorms in the Gobi Desert, pick up industrial emissions over China's megacities, and disperse across thousands of miles of the Pacific Ocean, all in a matter of days. The uppermost cloud layers can travel as far as the Atlantic Ocean.
Scientists are still unsure how much of the dusty soot settles into the lungs of North Americans. But they do know that the particles block sunlight and change regional temperature and precipitation patterns, which can mask global warming and modify storm tracks.