Global warming killing Indian farmers: study

Rising temperature due to global warming was responsible for the death of nearly 60,000 Indian farmers in the last 30 years, scientists claimed demonstrating a deleterious link between global warming and suicides.

The research by an economist at the University of California, Berkley, is probably the first one on the Indian farm sector to show how a dip in farm income — as a consequence of rising temperature — led thousands of farmers to commit suicides.

Suicide claims more than 1,30,000 lives in India each year, but the underlying causes are poorly understood. One hypothesis links suicide to extreme climate events that damage crop yields and increases farmers’ debt burdens.

To test this hypothesis, Tamma Carleton analysed suicide records of 47 years from India’s National Crime Records Bureau along with the official data on crop yields and high-resolution climate data.

“I demonstrated that fluctuations in climate, particularly temperature, significantly influence suicide rates. For temperature above 20 degrees Celsius, one degree increase in a single day’s temperature causes about 70 suicides on an average. This effect occurs only during India’s agricultural growing season,” Tamma reported in the Proceedings of National Academy of Sciences.

During the growing season, declines in agricultural yields at high temperatures mirrored the rise in suicide rates at high temperatures. By contrast, neither suicide rates nor agricultural yields were correlated with temperature after farming season. The economist calculated the additional number of deaths attributable to warming in the growing season throughout India since 1980 and found that by 2013, rising temperature trends were responsible for over 4,000 additional deaths annually across India, accounting for about 3% of annual suicides.

Across all states and all years since 1980, a cumulative total of 59,300 suicides can be attributed to warming, accounting for 6.8% of the national upward trend in suicide rates over this time period.

High growing season temperatures were associated with elevated suicide rates not only for the same year, but for up to five years in the future, and the temperature sensitivities of crop yields and suicides were correlated across regions.

She measured suicide rates in each of the 32 states and union territories and compared them with farm productivity. Karnataka is one of the states where farmers’ suicide could be attributed to rising temperature since 1980s.

The number of states with high-suicide rates, Tamma’s research showed, spread from Kerala, West Bengal and Tripura between 1967-77 to as many as 12 states including Karnataka after 1999.