The pope is likely to preach about climate change and economics when he is in the U.S.

President Obama is visiting Alaska and the Arctic to talk about climate change.

On the losing side of the new rules: coal.

'It's a life-and-death question' at the Pentagon, witness testifies.

The pope offers a moral interpretation of the global economy.

In a papal letter, Francis says wealthier countries need to help poorer ones.

An Italian magazine publishes a 192-page draft that calls for 'urgent action.'

The beetle has eaten almost all the host trees, leaving less dead wood to harvest.

A federal court in Washington hears a challenge to the EPA's Clean Power Plan.