By
the time today’s elementary schoolers graduate from college, the U.S.
corn belt could be forced to move to the Canadian border to escape
devastating heat waves brought on by rising global temperatures. If
farmers don’t move their corn north, the more frequent heat waves could
lead to bigger swings in corn prices—”price volatility”—which cause
spikes in food prices, farmers’ incomes and the price livestock farmers
and ethanol producers pay for corn.

   

A study published April 22 in the journal Nature Climate Change shows for the first time climate change’s outsized influence on year-to-year swings in corn prices.

   

Researchers
from Stanford and Purdue universities found that climate change’s
impact on corn price volatility could far outweigh the volatility caused
by changing oil prices or government energy policies mandating biofuels
production from corn and other crops.

   

“Frankly,
I was surprised that climate had the largest effect of these three
influences,” said Noah Diffenbaugh, an assistant professor of
environmental Earth system science at Stanford’s School of Earth
Sciences and a fellow at the Stanford Woods Institute for the
Environment. “These are substantial changes in price volatility that
come from relatively moderate global warming.”

   

The
study, based on economic, climatic and agricultural data and
computational models, finds that even if climate change stays within the
internationally recognized target limit of 3.6 F above pre-industrial
levels, the temperature changes could still make damaging heat waves
much more common over the U.S. corn belt.

   

“Severe
heat is the big hammer,” Diffenbaugh said. “Even one or two degrees of
global warming is likely to substantially increase heat waves that lead
to low-yield years and more price volatility.”

   

The
researchers calculate that when climate change’s effects are coupled
with federal mandates for biofuel production, corn price volatility
could increase sharply over the period from 2020 to 2040. Increasing
heat waves will lead to low-yield years, and government-mandated corn
sales to ethanol producers limit the market’s ability to buffer against
low-yield years.

   

“By
limiting the ability of commodity markets to adjust to yield
fluctuations, biofuels mandates work in exactly the wrong direction,”
said Thomas Hertel, a professor of agricultural economics at Purdue
University who participated in the study.

   

“Our
results suggest that energy policy decisions are likely to interact
with climate change to affect corn price volatility, and that the market
effect of a binding biofuel mandate is likely to intensify as the
climate warms,” Diffenbaugh said.

   

Diffenbaugh
and Hertel also explored the potential of farmers to adapt to the
changing climate. They found that, unless corn farmers increase their
crops’ heat tolerance by as much as 6 degrees Fahrenheit, the areas of
high corn production would have to move northward from the current U.S.
corn belt to near the Canadian border in order to avoid excessive heat
extremes.

   

“Our
goal was to explore the interacting influences of climate, energy
markets and energy policy,” said Diffenbaugh. “It is clear from our
results that those policy decisions could strongly affect the impacts
that climate change has on people. And, importantly, we also identify
potential opportunities for reducing those impacts through adaptation.”

   

Source: Stanford University