Renewable Fuel Standards designate the minimum levels at which several categories of biofuel are consumed through 2022.
Glen MacDonald, of UCLA, talks about the threat of drought in the Southwest and what it means for water supply.
Arctic warming and loss of sea ice may be helping to drive cold air southward, into the US and Europe, according to recent studies.
December brought unexpectedly chill temperatures to parts of Europe and the North Eastern U.S. We round up the cold snap visually.
November 30th marked the official end of the 2010 hurricane season, here are some pictures from this year's storms.
Lake Mead is at a record low level, a stark symbol of increased water demand and a stubborn drought in the West. Will conditions persist and the reservoir sink farther? Scientist David McGee reveals how he looks for the answers by studying past dry spells.
Comparison of early to mid-summer conditions along the eastern seaboard vs. the West Coast.
By mid-century in New York, the sweltering heat of July 2010 may be thought of as cooler-than-average conditions, as more days above 90Ã‚Â°F routinely occur.