Aerosol pollution may have suppressed global warming and increased Arctic sea ice from 1950-1975.
Study estimates that without new "congestion pricing" policy, kids would have suffered 45 percent more asthma attacks.
Access to a dark night sky is a universal human right, says the American Astronomical Society
Scientists find first evidence that oil from the spill reached land-based animals.
Scientists argue non-toxic alternatives such as steel would keep many tons of lead out of the environment each year.