The amounts are small, but the development could complicate U.S. efforts to control air pollution.
Scientists had long believed that most of Antarctica's continent-sized ice sheet was highly resistant to global warming.
But are we willing to live without blue skies?
Better known as laughing gas, this chemical compound has moved above CFCs as the No. 1 depleter of ozone.
Study suggests that lung functionality deteriorates in ozone concentrations less than the current clean-air standards.
NASA just released projections showing what the ozone layer would look like if we hadn't banned CFCs. Not a pretty picture.
After a change in direction, Purfresh is embracing ozone to help address global food shortages, tackle salmonella outbreaks and keep organics better, longer.
What Chu got to offer; "backsliding" on climate; Calif. fights CO2; the history of environmentalism; upset about offsets; EPA abandons rule changes; top eco-fugitives; we're in the ozone
Are aerosol sprays bad for the ozone layer?
