Crop-damaging temperatures increase suicide rates in India

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 114; no. 33; pp. 8746 - 8751
• Main Author: Carleton, Tamma A.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences 15.08.2017
• Series: From the Cover
• Subjects: Acclimatization; Acclimatization - physiology; Agricultural production; Agriculture; Climate; Climate change; Crop damage; Crop yield; Crops; Damage; Developing countries; Developing Countries - statistics & numerical data; Environmental impact; Hot Temperature; Humans; Income - statistics & numerical data; India; LDCs; Population studies; Seasons; Social Sciences; Suicide; Suicide - statistics & numerical data; Suicides & suicide attempts; Temperature; agriculture; weather impacts; climate; suicide; India
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.1701354114

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. I study India, where one fifth of global suicides occur and suicide rates have doubled since 1980. Using nationally comprehensive panel data over 47 y, I demonstrate that fluctuations in climate, particularly temperature, significantly influence suicide rates. For temperatures above 20 °C, a 1 °C increase in a single day’s temperature causes ∼70 suicides, on average. This effect occurs only during India’s agricultural growing season, when heat also lowers crop yields. I find no evidence that acclimatization, rising incomes, or other unobserved drivers of adaptation are occurring. I estimate that warming over the last 30 y is responsible for 59,300 suicides in India, accounting for 6.8% of the total upward trend. These results deliver large-scale quantitative evidence linking climate and agricultural income to self-harm in a developing country.