Clean Air Policy

Global warming is headed back to the future as the CO2 level reaches a new high

Diesel pollution has been cut by about 45,000 tons over the past five years through engine upgrades and replacements

Plans to clean up China's air may increase emissions of carbon dioxide

A Q&A with the new head of Advanced Research Projects Agency–Energy chemist Ellen Williams

Pres. Barack Obama vetoed a bill to approve construction of the Keystone XL Pipeline on February 24— not because of climate change, not because of low oil prices and not because of the risks from leaking diluted bitumen from the tar sands.

Chinese companies press forward with plans to process coal into other fuels, despite water scarcity and excess climate change pollution

Before the era of artificial lights, clouds hid the light coming from the stars. But now, the sky grows brighter when clouds roll in, possibly adversely affecting animals and plants

I can't seem to go a day without hearing someone say, "Get to Cuba before all the Americans get there." What exactly is it that Americans will change once they get to Cuba?

The Arctic is changing fast

An electric utility reliant on coal offers support for new greenhouse gas rules in exchange for changes to the plan

Ice cores show a sudden rise in heavy metal air pollution in South America 240 years before the industrial revolution, probably due to metallurgy and mining. Karen Hopkin reports

But can the Paris climate talks still be considered a success?