Pollution cloud over rice harvest

“If we let air pollution levels get worse, these effects are going to get larger,” University of California-Berkeley scientist Maximilian Auffhammer, one of the researchers, said in a telephone interview. “If we don’t do anything about this, things are not going to get better.”

India is one of the world’s major producers of rice. Broad agricultural improvements have boosted rice harvests in the 1960s and 1970s, making it self-sufficient in its staple food. The annual growth rate peaked at 2.7 per cent in the mid-1980s but growth has eroded since then, prompting worry about potential food shortages.

India’s rice harvest would have been more than 14 per cent better from 1985 to 1998 without the negative combined effects from the burning of fossil fuels and broader climate warming, the researchers said. “I don’t think it forecasts immediate doom and mass starvation or anything like that,” Auffhammer said. But he warned that India’s rice self-sufficiency could be threatened even as some experts forecast that its population will top China’s by the middle of the century.

Auffhammer and University of California-San Diego scientists V ‘Ram’ Ramanathan and Jeffrey Vincent examined historical data on India’s rice harvests and gauged the combined effects of atmospheric brown clouds and greenhouse gases on growing conditions.

The research indicated that the cooling effect of the brown clouds actually helped rice harvests by partially offsetting the warming effects of greenhouse gases, but not nearly as much as the drying effect from these clouds hurt the harvests.

“I don’t want to start some big stink, pointing fingers at the Indian government saying air pollution policy is something that should have been done,” Auffhammer said. “But I’d rather say, ‘Here’s the effect’, and this presents an incredible opportunity to make policy.”