From 2005 to 2010, the western US made huge leaps in cutting ozone-forming pollutants at a 21 percent decrease, but the ozone in the atmosphere did not drop because of a combination of pollutants drifting from China plus a natural uptick in ozone, according to a new study.
Scientists with NASA's Jet Propulsion Laboratory in Pasadena and from the Netherlands say Chinese emissions of ozone-forming pollutants increased 21 percent during those six years. Plus, due to natural cycles including the 2009-10 El Nino, an unusual amount of ozone drifted down from the stratosphere.
The fact that pollutants are migratory places greater pressure on achieving global agreements to reduce emissions. Ahead of climate talks in Paris this year, China has pledged to reduce its greenhouse gas emissions per unit of gross domestic product by 60-65 percent from 2005 levels. How will greenhouse gas emissions cuts contribute to reducing ozone? Practically speaking, how will China achieve those cuts?
Jessica Neu, Co-author of the research and research scientist with the Jet Propulsion Laboratory
Paul Joffe, Senior Foreign Policy Counsel and Manager of ChinaFAQs project with the World Resources Institute - a nonprofit policy organization focused on global environmental issues - founded by a MacArthur Foundation grant in 1982