While it’s sometimes hard to distinguish the crackpot from the consequential, many sober scientists believe that even far-out schemes are worth exploring, considering the alternatives.

Anew study raises concerns that releasing hydrogen into the atmosphere might damage the ozone layer, alter global climate, and change the growth rates of soil microbes.

The government should be spending more on deep sea research than on deep space research.

Although it creates only a slight reduction in the amount of solar energy absorbed by the Earth, solar radiation management should be a part of U.S. climate policy.

Under pressure from environmentalists, the coal industry and its supporters are claiming that their fuel can be clean.

Real progress on climate policy will require many, many decades.

Air pollution has been a part of human existence for thousands of years, and accounts of noxious urban air go back to ancient times.

Biodiversity, which evolved over more than 3 billion years, is being eroded at an accelerating rate by human activity.