A farmer works in a millet field while cattle graze nearby on the outskirts of Bengaluru, India, on June 9, 2017.

Climate change has been linked to the suicides of almost 60,000 people over the last three decades in India, a study published Monday has revealed.

For temperatures above 20 degrees Celsius, an increase of a single degree causes approximately 70 suicides, according to a researcher at the University of California, Berkeley. The link is understood to only occur during India's agricultural growing season, when excess heat means a lower crop harvest.

Warming temperatures over the past 30 years have been responsible for an estimated 59,000 suicides in India, Tamma Carleton, PhD student in agricultural economics at Berkeley and author of the study wrote.

The link to farming is significant. More than half of India's working population is employed in the sector, which is known for its suicide rate.

Some believe that this boils down to financial inclusion. Villages in rural communities where farming is widespread often have traditional money lenders who charge far higher rates than formal banks. When crop yields are down and farmers are forced to borrow money, they fall into debt. Indian farming is dependent on seasonal monsoon rains, and with these becoming increasingly erratic in recent years, the farmer suicide rate is thought to have responded to in kind.

According to the Indian National Crime Records Bureau in a report on suicide among farmers, 'Bankruptcy or Indebtedness' and 'Farming Related Issues' are reported as major causes of suicides, accounting for 38.7 percent and 19.5 percent respectively during 2015.