Jul 31, 2017

Crop-damaging temperatures increase suicide rates in India

Tamma A. Carleton
Proceedings of the National Academy of Sciences
  • States that more than three quarters of the world’s suicides occur in developing countries, yet little is known about the drivers of suicidal behavior in poor populations
  • Looks at India, where one fifth of global suicides occur and suicide rates have doubled since 1980
  • Uses nationally comprehensive panel data over 47 years
  • Demonstrates that fluctuations in climate, particularly temperature, significantly influence suicide rates
  • Finds that for temperatures above 20 °C, a 1 °C increase in a single day’s temperature causes ∼70 suicides, on average
  • Finds that this effect occurs only during India’s agricultural growing season, when heat also lowers crop yields
  • Finds no evidence that acclimatization, rising incomes, or other unobserved drivers of adaptation are occurring
  • Estimates that warming over the last 30 years is responsible for 59,300 suicides in India, accounting for 6.8% of the total upward trend
  • Results deliver large-scale quantitative evidence linking climate and agricultural income to self-harm in a developing country