The big O
Though broccoli is now growing in usually icy Greenland, and frost has yet to bite the basil plants in parts of the Southern United States, the seemingly positive effects of global warming in some regions may be counteracted by increasing levels of ozone.
An MIT study, reported in the November issue of Energy Policy, focuses on how increases in temperature, carbon dioxide and ozone will affect crops, pastures and forests. It found that higher temps and carbon dioxide levels may actually benefit vegetation, but ozone—an atmospheric pollutant at ground level—may negatively offset those benefits. According to the report, crops are hit the hardest. Without emissions restrictions, by 2100, the global value of crop production will fall by 10 to 12 percent, and the global average ozone level will be up 50 percent.
Global warming impacts vary from region to region. The northern temperate regions, for example, would likely benefit from extended growing seasons but also face large crop losses due to high ozone concentrations. Regions such as the United States, China and Europe would need to import food, and tropical regions would benefit from supplying those imports, the study said.