Can Adaptation of Agricultural Practices Reduce the Impact of Surface Ozone on Global Food Supply?

Surface ozone (O3) is a potent phytotoxic air pollutant that reduces productivity of agricultural crops. Growing use of fossil fuel and changes in climate are increasing O3 concentrations to levels that threaten food supply. Historically, farmers have successfully adapted agricultural practices to cope with contrasting environments. However, high O3 concentrations are a new threat to be dealt with in food production systems. We simulated the impact of adapting agricultural practices to minimize ozone damage for four key crops (wheat, maize, rice and soybean). Ozone impact is influenced by shifting crop calendars, 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. The use of irrigation largely affects ozone exposure but local impact depends on seasonality of pollutant emissions and local climate. Adaptation by shifting crop calendars can reduce local O3 damage (e.g. 28% for rainfed soybean in India) but has limited impact at global level (