Explainers

Learn how heat from the Earth is converted into electricity in this comprehensive overview, including a discussion of the geothermal resource, its environmental and societal impacts, and its potential for future expansion.

Learn how moving water is converted into electricity in this comprehensive overview, including a discussion of the hydropower resource, its environmental and societal impacts, and the potential for future expansion of hydroelectic energy.

Hundreds of US nuclear warheads are kept ready to launch within minutes—making us less safe, not safer.

When developed from the right sources, biofuels offer huge potential as a clean-burning alternative to oil.

Coal-fired power plants, which produce a significant share of US electricity, have significant impacts on water quantity and quality.

A summary of Virginia Attorney General Ken Cuccinelli's misguided investigation of respected climate scientist Michael Mann.

How does local food move from the fields to the table?

Smart planning and thoughtful safeguarding—not weaponization—will protect US interests in space.

Cars and trucks are one of the leading causes of air pollution—but cleaner vehicles can help.

Transportation is one of the largest sources of US global warming emissions—but cleaner vehicles can help.

Tropical deforestation accounts for about 10 percent of the world’s global warming emissions.

Tropical deforestation accounts for about 10 percent of the world's global warming pollution. Here are ten reasons why protecting tropical forests is in the United States' best interest.