SAN FRANCISCO, CALIFORNIA -- (By Lisa Strong-Aufhauser) Even the snow on top of the Greenland ice sheet is not as pure as you’d think. Dr. Joe McConnell from the Desert Research Institute in Reno, Nevada, studies the impurities... {Read More »}

Carbon dioxide is a colorless, odorless gas that makes up .04 percent of the earth’s atmosphere. It’s released by the breakdown of organic materials, by animals when they respire, and by the burning of fossil fuels. Carbon dioxide isn't toxic—after all, we exhale it with every breath and use it to make our drinks fizzy. However, as a greenhouse gas, it’s a significant contributor to global warming. {Read More »}