A national emergency is the best way to combat the crisis, he says.
Dem AGs have filed suit.
More than a century of data shows some places have warmed beyond 2 degrees Celsius.
Candidates want national service programs to help slow global warming.
The stress could only get worse as the climate warms.
Administration moves forward with rule as blue states sue.
Global warming is a kitchen table issue that affects the whole U.S. economy, they say.
Her answer on "environmental injustice" was a surprisingly good soundbite.
They want to help disadvantaged communities stave off pollution.
The California deal put rival car companies in a pickle.