greenhouse gases

President Obama says the U.S. will sharply cut its emissions of greenhouse gases, announcing a new approach to climate change alongside Chinese President Xi Jinping. The plan also includes China's agreement to cap its emissions.

The two leaders' pledges are being called dramatic and ambitious — for the U.S., because Obama's earlier plans had called for a smaller cut in emissions, and for China, because the country had previously resisted calls for it to consider capping its emissions as it grows and modernizes.

The U.S. Supreme Court gave the Environmental Protection Agency the green light to regulate greenhouse gases that are emitted from new and modified utility plants and factories on Monday.

Greenhouse gases are blamed for global warming, and the court's 7-2 decision gave the EPA most of what it wanted. But in a separate 5-4 vote, the justices rejected the agency's broad assertion of regulatory power under one section of the Clean Air Act.

We Americans are heavy consumers of meat, and we're increasingly reminded that eating less of it will shrink our carbon footprint. Growing the crops to feed all those animals releases lots of greenhouse gases.