Ozone levels across Northern Hemisphere have been rising for 20 years

Washington DC (UPI) Aug 21, 2020

While emission levels for ozone-forming chemicals have fallen in some North American cities, new research suggests tropospheric ozone levels have increased across the Northern Hemisphere over the last 20 years. In the upper layers of the atmosphere, the ozone layer helps protect Earth and its inhabitants from harmful ultraviolet radiation. But closer to Earth's surface, ozone cau