Guest essay by Eric Worrall
A new study claims every degree of temperature above 20C increase the likelihood an Indian farmer will commit suicide. Just one problem with this claim: Indian agricultural yields are rising (see graph above).
Crop-damaging temperatures increase suicide rates in India
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.
Read more: http://www.pnas.org/content/early/2017/07/25/1701354114
Unfortunately the full study is paywalled, so we don’t get to see the magic by which the authors process a rising agricultural yield into a climate threat. But the base OECD dataspeaks for itself.
Even if temperature is a negative, other factors such as global greening, CO2 induced drought resilience, improved agricultural technology and Prime Minister Modi’s efforts to improve rural access to cheap energy are more than compensating for any negative factors.