How do planets form? For many years scientists thought they understood this process by studying the one example we had access to: our own...

The U.N. health agency says nearly everybody in the world breathes air that doesn't meet its standards for air quality, calling for more action...

The latest report by the Intergovernmental Panel on Climate Change (IPCC), released overnight, shows a viable path to cutting global emissions by half by...

It's a major source of California's water supply and a vital habitat for fish, migratory birds and other species. But the Sacramento-San Joaquin River Delta...

It's not the end of the world. It only seems that way. Climate change is going to get worse, but as gloomy as the latest...

Part of the shock wave is shrinking rather than expanding. A powerful shock wave traveling through a cloud of gas left behind by the explosive...