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Estimates in a study published Monday indicate that climate change
has led to failing harvests that push farmers into poverty and cause
more than 59,000 suicides in India over the last 30 years.
University of California, Berkeley, researcher Tamma Carleton
discovered that warming a single day by 1 degree Celsius, or 1.8 degrees
Fahrenheit, during India's agricultural growing season leads to roughly
65 suicides across the country, whenever that day's temperature is
above 20 degrees Celsius, or 68 degrees Fahrenheit. Warming a day by 5
degrees Celsius has five times that effect.
Published in the Proceedings of the National Academy of Sciences
(PNAS), the study helps explain India's evolving suicide epidemic, where
suicide rates have nearly doubled since 1980 and claim more than
130,000 lives each year.
While high temperatures and low rainfall during the growing season
impact annual suicide rates, similar events have no effect on suicide
rates during the off-season, when few crops are grown, implicating
agriculture as the critical link.
Finding that 7 percent of this upward trend can be attributed to
warming that has been linked to human activity, Carleton acknowledged
that "it was both shocking and heartbreaking to see that thousands of
people face such bleak conditions that they are driven to harm
themselves."
More than 75 percent of the world's suicides are believed to occur in
developing countries, according to a UC Berkeley news release, with
one-fifth of those in India alone.
Using methods that she developed in a previous paper published in the
journal Science, Carleton, a doctoral fellow at UC Berkeley's Global
Policy Laboratory and a Ph.D. candidate in agriculture and resource
economics, projected that today's suicide rate will only rise as
temperatures continue to warm. "Without interventions that help families
adapt to a warmer climate, it's likely we will see a rising number of
lives lost to suicide as climate change worsens in India."
More than half of India's working population is employed in
rain-dependent agriculture, long known to be sensitive to climate
fluctuations such as unpredictable monsoon rains, scorching heat waves,
and drought. Heat drives crop loss, which can cause ripple effects
throughout the Indian economy as poor harvests drive up food prices,
shrink agricultural jobs and draw on household savings. During these
times, it appears that a staggering number of people, often male heads
of household, turn to suicide.
Carleton tested the links between climate change, crop yields and
suicide by pairing the numbers for India's reported suicides between
1967 and 2013, using a dataset prepared by the Indian National Crime
Records Bureau, along with statistics on India's crop yields, and
climate data. To isolate the types of climate shocks that damage crops,
she focused on temperature and rainfall during June through September, a
critical period for crop productivity that is based on the average
arrival and departure dates of India's summer monsoon.
She cautioned that her estimates of temperature-linked suicides are
probably too low, because deaths in general are underreported in India
and because national law held that attempted suicide was a criminal
offense until 2014, further discouraging reporting.
In response to rising suicide rate, the Indian government has
established a crop insurance plan equivalent to 1.3 billion U.S.
dollars.
Advocating protecting rural workers from major economic shortfalls in
time of warming, forecast to reach 3 degrees Celsius by 2050, through
policies like crop insurance or improvements in rural credit markets,
Carleton warned that "without interventions that help families adapt to a
warmer climate, it's likely we will see a rising number of lives lost
to suicide as climate change worsens in India."
