Several factors, including La Niña events, have contributed to the expanded drought, meteorologists say. Conditions in the West may be setting up for a 'megadrought' by century's end, researchers warn.
The unusual heat waves felt in Texas, Oklahoma, Moscow, and elsewhere in recent years are almost certainly a result of global warming, according to a study led by NASA scientist and climate activist James Hansen.
Researchers have found new evidence of modern culture's beginnings in a cave in South Africa. These findings may indicate that 'modern behavior as we know it' has existed for longer than previously thought.
Polar and brown bears diverged between 4 million and 5 million years ago, but they continued to interbreed when the climate warmed, finds a new study led by the University at Buffalo and Penn State. Now, there is evidence that it is happening again.