British scientists from the Met Office, the University of Exeter and the Centre for Ecology & Hydrology have found in a new study that rising surface ozone could significantly reduce plant growth and crop reduction while adding to global warming.
Surface ozone damaged plants, affecting their ability to soak up carbon dioxide from the atmosphere, thereby and accelerating global warming, said Dr Stephen Sitch, a climate impacts scientist at the Met Office Hadley Centre and lead author of the article.
He said near-surface ozone had doubled since 1850 due to chemical emissions from vehicles, industrial processes, and the burning of forests.
"Climate models have largely ignored atmospheric chemistry but in this research we have identified a cause of potentially increased warming with elevated levels of surface ozone likely to suppress plant growth," he said.
Dr. Sitch said though plants and soil were currently slowing-down global warming by storing about a quarter of human carbon dioxide emissions, this could be undermined by further increases in near-surface ozone.
As a result more carbon dioxide would accumulate in the atmosphere and add to global warming, said co-author, Professor Peter Cox of the University of Exeter.
"We estimate that ozone effects on plants could double the importance of ozone increases in the lower atmosphere as a driver of climate change, so policies to limit increases in near-surface ozone must be seen as an even higher priority," said Professor Peter Cox.
The research is published online in Nature.