July 30, 2014
Climate Change and Pollution Threaten Global Food Supply
by Robert Kropp
A study by Massachusetts Institute of Technology concludes that reductions in crop yields due to
climate change can be offset somewhat by stronger ozone pollution controls.
Global food supply threatens to be one of the worst effects of climate change. The world's
population is projected to grow to nine billion people, and along with the changing dietary
requirements of citizens of developing nations, food demand is expected to increase by as much as
50% by 2050.
At the same time, extreme drought and
other long-term weather effects due to climate change are likely to reduce global food supply. And,
according to a new study out of the Massachusetts Institute of Technology, air pollution—especially ozone
pollution—will combine with climate change to make reductions in the yields of important crops even
In the report, the authors
state, “we present an integrated analysis of the individual and combined effects of 2000–2050
climate change and ozone trends on the production of four major crops (wheat, rice, maize and
soybean) worldwide based on historical observations and model projections, specifically accounting
for ozone–temperature co-variation.” The four crops studied in the report account for more than
half the calories consumed by humans globally.
As the report points out, global warming
due to climate change is expected to reduce agricultural yields by more than ten percent. However,
the effect will be compounded to a considerable degree by ozone pollution: “the team found that 46
percent of damage to soybean crops that had previously been attributed to heat is actually caused
by increased ozone,” MIT states.
In areas of the world where malnutrition is a threat,
rates could rise from the current level of 18% to 27% if decisive pollution controls are not
enacted; if they are, then malnutrition is likely to increase due to climate change, but the rate
could be as much as halved.
Agricultural production is “very sensitive to ozone
pollution,” report co-author Colette Heald said. She added that the findings of the report ““show
how important it is to think about the agricultural implications of air-quality regulations. Ozone
is something that we understand the causes of, and the steps that need to be taken to improve air
Commenting on the findings, Denise Mauzerall of Princeton University said, “The
increased use of clean energy sources that do not emit either greenhouse gases or conventional air
pollutants, such as wind and solar energy, would be doubly beneficial to global food security, as
they do not contribute to either climate change or increased surface-ozone concentrations.”
SRI World Group, Inc. All Rights Reserved.