Skip to main content

Extreme heat and droughts -- a recipe for world food woes

By Michael Roberts, Special to CNN
updated 5:24 PM EDT, Mon August 13, 2012
The drought had a negative impact on corn in Le Roy, Illinois. Drought occurred in six Plains states between last May and August because moist Gulf of Mexico air "failed to stream northward in late spring," and summer storms were few and stingy with rainfall, said a report by the National Oceanic and Atmospheric Administration. The drought had a negative impact on corn in Le Roy, Illinois. Drought occurred in six Plains states between last May and August because moist Gulf of Mexico air "failed to stream northward in late spring," and summer storms were few and stingy with rainfall, said a report by the National Oceanic and Atmospheric Administration.
HIDE CAPTION
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
Extreme heat, drought ravage Midwest
<<
<
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
>
>>
STORY HIGHLIGHTS
  • Michael Roberts: Extreme heat and drought are signs of a changing climate
  • Roberts: Farmers and U.S. consumers will be fine; food prices will go up a bit in 2013
  • He says the crop losses will have the most effect on the world's poorest populations
  • Roberts: This summer's extreme heat may just become typical in 15 years

Editor's note: Michael Roberts is an associate professor of economics and Sea Grant Affiliate at the University of Hawaii, Manoa. He is currently on leave from the department of agricultural and resource economics at North Carolina State University.

(CNN) -- With extreme heat and the worst drought in half a century continuing to plague the farm states, there are important lessons to be learned for all of us -- farmers, consumers and the world's poorest populations alike -- about the effect of climate change.

The Agriculture Department announced this season's first major crop yield forecasts, and they weren't pretty: a nationwide average of 123.4 bushels of corn per acre, the lowest level since 1995. Soybean yield is expected to be low too, though not as bad as corn.

The United States, which is the world's largest producer and exporter of staple grains, is grappling with the biggest surprise in production shortfalls since the Dust Bowl of the 1930s. Certainly, this July surpassed July 1936 as the hottest month on record.

So, how will the devastation affect U.S. crop farmers?

Drought to push food prices higher
Ag. Secy. on drought relief distribution
Drought troubles in the United States
Obama on nation's drought

Drought, heat bring spiders out

Since mid-June, corn prices have risen about 60%, more than twice the projected decline in yield. This means that farm revenue will go up. About 90% of the corn acreage is backed by a generously subsidized federal insurance program, described by Steven Colbert as "Obamacare for the corn," so crop farmers will be just fine. Livestock farmers who use corn to feed their animals could see higher costs, but most have contracts with processors who provide their feed grains.

What about consumers? Will high commodity prices affect the prices of food you eat? Not much, actually.

Commodity prices account for just a tiny share of retail food prices. If you're a shrewd shopper, next year you may notice higher prices for meat, milk, eggs, and cheese and all types of processed foods. The USDA estimates that food prices will increase 3 to 4% in 2013. This is not going to radically change your life. People in rich countries like the U.S. are not going to eat much less or much differently as a result of modestly higher prices.

The crop losses will have the most effect on the world's poorest populations. About 2 billion people still live on $2 a day or less. Many of them live in urban areas of developing countries. Often, they must spend half or more of their income on food, the bulk coming from staple grains like corn, wheat and rice. For these people, a huge rise in grain prices is more than noticeable -- it can literally break their budget.

In 2008 and 2011, when corn prices went up to levels nearly as high as today's, the world saw a sharp rise in food riots. Many pointed to wheat prices as a catalyst for revolutions in the Middle East, including Egypt, Tunisia and Libya. It is not hard to see that food-related security problems overseas could cost us far more than the extra pennies we'll pay at the grocery store.

NASA scientist links climate change, extreme weather

The U.S. can ease price pains somewhat by suspending government rules that mandate biofuel production. In 2011, about 40% of U.S. corn crops were diverted to ethanol (a quarter, if we take into account that nutritional content is recycled back into feeds for animals in the form of distiller grains). But this seems untenable politically.

The larger and more important issue is whether this year's bad crop yield is an omen of what we should expect going forward.

Record high temperatures are occurring with far greater frequency than in decades past, and crop yields decline sharply in extreme heat. In research that Wolfram Schlenker and I have conducted using the Hadley III climate model, we project yield declines of about 20% over the next 20 years, holding all else the same. This summer's extreme heat may just become typical in 15 years.

Some have criticized these projections as too pessimistic, and they just might be. An atmosphere richer in carbon dioxide concentrations may allow plants to transpire less water during photosynthesis, and thus, improve drought tolerance. Farmers can adjust to earlier planting times, perhaps avoiding some extreme temperatures during the sensitive flowering period, and lengthening the growing season. And new drought-tolerant crop varieties have been developed.

This season was a good test of these adaptive strategies. It appears they didn't work. Carbon dioxide concentrations are much higher than they were in 1983 and 1988, when it was nearly as hot as this summer. And farmers planted much earlier than usual, many using new drought-tolerant varieties.

Record drought is good business for some

For now, we can take a little comfort that ample harvests in the Dakotas, Minnesota and parts of the South could make up for some of the decimated crops in the central Midwest this year.

But next year? And the years after? In the long term, a warming world will be a difficult challenge for our crops and all of us.

Complete coverage: drought

Follow us on Twitter @CNNOpinion.

Join us on Facebook/CNNOpinion.

The opinions expressed in this commentary are solely those of Michael Roberts.

ADVERTISEMENT
Part of complete coverage on
updated 8:37 AM EDT, Tue October 28, 2014
Errol Louis says forced to choose between narrow political advantage and the public good, the governors showed they are willing to take the easy way out over Ebola.
updated 2:03 PM EDT, Mon October 27, 2014
Eric Liu says with our family and friends and neighbors, each one of us must decide what kind of civilization we expect in the United States. It's our responsibility to set tone and standards, with our laws and norms
updated 7:45 AM EDT, Mon October 27, 2014
Sally Kohn says the UNC report highlights how some colleges exploit student athletes while offering little in return
updated 3:04 PM EDT, Sun October 26, 2014
Terrorists don't represent Islam, but Muslims must step up efforts to counter some of the bigotry within the world of Islam, says Fareed Zakaria
updated 9:02 AM EDT, Fri October 24, 2014
Scott Yates says extending Daylight Saving Time could save energy, reduce heart attacks and get you more sleep
updated 8:32 PM EDT, Sun October 26, 2014
Reza Aslan says the interplay between beliefs and actions is a lot more complicated than critics of Islam portray
updated 7:19 AM EDT, Mon October 27, 2014
Julian Zelizer says control of the Senate will be decided by a few close contests
updated 8:12 AM EDT, Fri October 24, 2014
The response of some U.S. institutions that should know better to Ebola has been anything but inspiring, writes Idris Ayodeji Bello.
updated 5:01 PM EDT, Wed October 22, 2014
Paul Callan says the grand jury is the right process to use to decide if charges should be brought against the police officer
updated 12:19 PM EDT, Thu October 23, 2014
Theresa Brown says the Ebola crisis brought nurses into the national conversation on health care. They need to stay there.
updated 6:35 PM EDT, Tue October 21, 2014
Patrick Hornbeck says don't buy the hype: The arguments the Vatican used in its interim report would have virtually guaranteed that same-sex couples remained second class citizens
updated 12:30 PM EDT, Fri October 24, 2014
The Swedes will find sitting on the fence to be increasingly uncomfortable with Putin as next door neighbor, writes Gary Schmitt
updated 12:32 PM EDT, Fri October 24, 2014
The Ottawa shooting pre-empted Malala's appearances in Canada, but her message to young people needs to be spread, writes Frida Ghitis
updated 9:48 PM EDT, Sat October 25, 2014
Paul Begala says Iowa's U.S. Senate candidate, Joni Ernst, told NRA she has right to use gun to defend herself--even from the government. But shooting at officials is not what the Founders had in mind
updated 6:08 PM EDT, Thu October 23, 2014
John Sutter: Why are we so surprised the head of a major international corporation learned another language?
updated 5:54 PM EDT, Thu October 23, 2014
Jason Johnson says Ferguson isn't a downtrodden community rising up against the white oppressor, but it is looking for justice
updated 12:21 PM EDT, Fri October 24, 2014
Sally Kohn says a video of little girls dressed as princesses using the F-word very loudly to condemn sexism is provocative. But is it exploitative?
updated 4:06 PM EDT, Tue October 21, 2014
Timothy Stanley says Lewinsky is shamelessly playing the victim in her affair with Bill Clinton, humiliating Hillary Clinton again and aiding her critics
updated 10:14 AM EDT, Thu October 23, 2014
Imagine being rescued from modern slavery, only to be charged with a crime, writes John Sutter
updated 12:00 PM EDT, Tue October 21, 2014
Tidal flooding used to be a relatively rare occurrence along the East Coast. Not anymore, write Melanie Fitzpatrick and Erika Spanger-Siegfried.
updated 7:35 AM EDT, Tue October 21, 2014
Carol Costello says activists, writers, politicians have begun discussing their abortions. But will that new approach make a difference on an old battleground?
updated 9:12 AM EDT, Tue October 21, 2014
Sigrid Fry-Revere says the National Organ Transplant Act has caused more Americans to die waiting for an organ than died in both World Wars, Korea, Vietnam, Afghanistan and Iraq
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT