Atmospheric Environment, 45(15): (May 2011); DOI: 10.1016/j.atmosenv.2011.02.002

Limited potential of crop management for mitigating surface ozone impacts on global food supply

Edmar Teixeira, Guenther Fischer, Harrij van Velthuizen, Rita van Dingenen, Frank Dentener, Gina Mills, Christof Walter and Frank Ewert

Abstract

Surface ozone (O₃) is a potent phytotoxic air pollutant that reduces the productivity of agricultural crops. Growing use of fossil fuel and climate change are increasing O₃ concentrations to levels that threaten food supply. Historically, farmers have successfully adapted agricultural practices to cope with changing environments. However, high O₃ concentrations are a new threat to food production and possibilities for adaptation are not well understood. We simulate the impact of ozone damage on four key crops (wheat, maize, rice and soybean) on a global scale and assess the effectiveness of adaptation of agricultural practices to minimize ozone damage. As O₃ concentrations have a strong seasonal and regional pattern, the adaptation options assessed refer to shifting crop calendars through changing sowing dates, applying irrigation and using crop varieties with different growth cycles. Results show that China, India and the United States are currently by far the most affected countries, bearing more than half of all global losses and threatened areas. Irrigation largely affects ozone exposure but local impacts depend on the seasonality of emissions and climate. Shifting crop calendars can reduce regional O₃ damage for specific crop-location combinations (e.g., up to 25% for rain-fed soybean in India) but has little implication at the global level. Considering the limited benefits of adaptation, mitigation of O₃ precursors remains the main option to secure regional and global food production.

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Highlights

► Global modeling of surface ozone (O₃) damage for maize, wheat, rice and soybean crops. ► We evaluate benefits of adapting crop management to reduce yield losses. ► Changes in sowing date, crop variety and irrigation had little global implication.► At regional level adaptive options may be effective. ► Security of food supply may benefit more from mitigating emission of O₃ precursors.

http://www.sciencedirect.com/science/article/pii/S135223101100118X