Climate change is already pushing Indian farmers and agricultural labourers over the edge. Temperature increases during crop-growing season could be the cause of 60,000 farm suicides throughout India over the last three decades, according to a new analysis published Monday in the science journal Proceedings of the National Academy of Sciences (PNAS).

"When temperatures rise to levels that damage crops, suicide rates also go up. It appears that crop losses are the key culprits linking self-harm to hot temperatures," says Tamma Carleton, the study's author and researcher at agriculture and resource economics, University of California, Berkeley. "These are deaths that would not have occurred, had the warming we've observed in the historical climate record not taken place."

Linking climate change, particularly temperature, and agricultural income with farmers' suicides, Carleton's study says that "for days above 20 ◦C, a 1 ◦C increase in a single day's temperature during the growing season increases annual suicides by 0.008 per 100,000 people, causing an additional 67 deaths, on average across India."

That means, an increase of 3 degrees Celsius on any day causes 201 deaths; an increase of 4 degrees Celsius on any day causes 268 deaths; and an increase of 5 degrees Celsius on any day causes 335 deaths. It further states that "annual crop yields fall by 1.3% per standard deviation in growing season temperatures."

All in all, Carleton estimates that Global Warming is responsible for 59,300 suicides in India over the last 30 years, showing agriculture's extreme vulnerability to temperature changes, rainfall, and farm suicides. Non-farmers too face distress, as crop losses ripple though economy, spiking up food prices and bringing down demand for agricultural labour.

"These are consequences of climate change that are already being felt today, underscoring the urgency of developing sound climate change policy. These devastating impacts of climate change are a problem faced by our generation, not a problem that we can afford to defer to future years," says Carleton, who studies the many ways that the climate affects global economic and social stability.

Suicide, she continues, is a heartbreaking indicator of human hardship. Carleton says she was struck by reports that indicated many suicides in India occur through ingestion of pesticides.

"This fact demonstrates that many of those in distress have livelihoods that are closely tied to agriculture, and encouraged me to investigate whether climatic effects on suicide rates were occurring because of damages to agricultural incomes."

The finding that suicide phenomenon is affected by a changing climate implies that it is essential to quantify its effect and consider this relationship as we build climate policy for the future, Carleton notes.

While high temperatures and low rainfall during the growing season substantially impact annual suicide rates, Carleton's study finds that similar climate events have no effect on suicide rates during the off-season, when few crops are grown, "implicating agriculture as the critical link."

Going forward in times of global warming

Even as India gradually warmed while experiencing economic growth, Carleton finds no evidence that people in India have been able to come to terms with a warming climate. The relationship between temperature and suicide is the same across different populations within India, and at different points in time.

"Without substantial investments in adaptive technologies and behaviours, this finding means that it's likely we will see a sustained rise in suicide rates as climate change continues to unfold in India, she warns.

To mitigate that, India must needs to implement immediate measures at farmers', communities', and policy levels.

First is the realization that changing climate is driving farm suicides. Second, Carleton suggests, are policies that " seek to reduce suicides by weakening the link between a risky climate and agricultural incomes."

Although Carleton's study doesn't fully go into what measures work, she suggests a range of options: crop insurance, which protect farm incomes from the vagaries of the climate, could be successful in reducing suicides. Access to low-interest loans through well-functioning rural credit markets may also help limit the damage caused by warming temperatures, as farmers can access quality seed without incurring debt burdens that become insurmountable.

Other possible adaptive responses could include farm-based solutions to protect yields against warming temperatures, such as crop switching to increase heat tolerance, or investment in irrigation technologies to combat rainfall variability. "I hope that future research will help to fill this important gap in our understanding of how we can work to slow the tragic rise in suicide in India," the author adds.

This Author

G.B.S.N.P Varma is a freelance journalist based in India, with an interest in climate science, environment, and ecology.