Ozone Could Slash Global Crop Yields by 40% by Century's End

We recently told you of a study warning that global warming could prompt the large-scale collapse of the world's crops by 2080; now comes another study concluding that rising levels of ozone could achieve the same result by century's end. The study, which appears in November's issue of Energy Policy, determined that while increases in temperature and carbon dioxide levels may actually benefit vegetation in the short run, rising ozone levels would more than offset those gains by harming crops.

While the damage wouldn't be felt equally - with some regions harder hit than others - the overall economic ramifications would be considerable, the researchers concluded: the global value of crop production could fall by as much as 12% by 2100 if nothing is done. John M. Reilly, the associate director of MIT's Joint Program on the Science and Policy of Global Change, estimates the rise may be as large as 50%.

Using MIT's proprietary Integrated Global Systems Model, Reilly and his colleagues looked at the combined impact of higher temperatures, carbon dioxide levels and ozone concentrations on crop production levels. When the effects of ozone were not included, they found that vegetation benefited as a whole - albeit temporarily. Including the ozone levels yielded decidedly different results.

Crops, which tend to be situated in areas with high ozone levels, would be particularly stunted because they are fertilized. "When crops are fertilized, their stomata open up, and they suck in more air. And the more air they suck in, the more ozone damage occurs," Reilly explained.

While other regions could help alleviate the losses by allocating more land to crops - thus preventing the projected 40% decline in crop yields - the shift would come at a large cost. The actual effects could be even worse, cautioned Reilly, as a result of the MIT model's less robust climate simulation. He plans on rectifying that discrepancy by re-running the numbers with a better model.

Via ::MIT News: Human-generated ozone will damage crops, according to MIT study (news release), ::Green Car Congress: Study: Human-Generated Ozone Could Cut Global Crop Yields by Nearly 40% by 2100 (blog)

See also: ::Global Warming Could Cause World Crop Collapse, ::::Shhhh, We've Got a Secret: Soil Solves Global Warming, Part 1
Images courtesy of John M. Reilly

Tags: Carbon Dioxide | China | Ozone | United States

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