It is, however, unsafe to breathe.
In his second inaugural address, the president made a strong call for climate action.
It wasn't Biden's only stop last night.
In Alameda County, Calif., stores are getting around the new plastic-bag ban by calling plastic bags "reusable."
Scientists have discovered a new floating garbage island off the coast of Chile.
The 787 is designed to be a "super-efficient" airplane, but the batteries that make that efficiency possible have been causing big problems.
A little winter isn't going to stop the worst drought in decades.
Canadian pipeline company Enbridge is losing business as oil companies increasingly ship their product by rail instead of pipeline.
The threatened expiration of the wind tax credit meant that the end of 2012 was huge for the wind industry.
We've devised the world's shortest survey to find out what kind of actions our readers are taking. You know you want to.