Ozone pollution costs Asia billions in lost crops

TOKYO: Persistently high levels of ozone pollution in Asia are costing China, Japan and South Korea an estimated $63 billion annually in lost rice, wheat and maize crops, a new study says.

While ozone forms a protective layer around the Earth in the upper atmosphere, it is a harmful pollutant at ground level. It is created by a chemical reaction when two pollutants, often emitted by cars or industry, combine in the presence of sunlight and it can interfere with plant photosynthesis and growth.

The research published on Monday harnesses pollution monitoring data from the region and field experiments to show ozone affects Asia’s crop yields more than previously thought. The study’s authors said the findings should push policymakers to reduce emissions that produce ozone.

"Air pollution control in North America and Europe succeeded in lowering ozone levels," said Kazuhiko Kobayashi, a co-first author of the study and professor emeritus affiliated with the University of Tokyo. "We need to repeat that success across East and South Asia," he said.