Research from Avery Cohn, assistant professor of environment and resource policy at the Fletcher School, claims that climate change expected over the next decade may cause food production in a key agricultural region of Brazil to decline by up to 13%. This decline reflects both reductions in crop yield and how crop failures and farmers' decisions together lead to cultivating less land and growing only one crop in a season instead of two.
Changes in rainfall and temperature affect not just whether crops are abundant at harvest, but also whether they live that long. Previous research has failed to account for losses from crops dying before they can be reaped, it may have underestimated the effects of climate change on the food supply.
The study focused on Mato Grosso, a state in Brazil that supplies 10% of the world's soybeans. Published in the journal Nature Climate Change, suggests that an increase in temperature of 1 degree Celsius in Mato Grosso will lead to a 9-13% reduction in soy and corn production. Most of that decrease would be due to the combination of crop failure and farmers' decisions to sow fewer crops, rather than lower yields on the crops harvested.
The researchers found that hot and wet conditions were associated with the largest losses and cool and dry conditions with the largest gains. They used satellite data from 2002 to 2010 to track land use and compared the changes to climate data.