Skip to main content

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

By Michael Roberts, Special to CNN
August 13, 2012 -- Updated 2124 GMT (0524 HKT)
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
July 11, 2014 -- Updated 1315 GMT (2115 HKT)
Michael Werz says in light of the spying cases, U.S. is seen as a paranoid society that can't tell friends from foes.
July 11, 2014 -- Updated 1317 GMT (2117 HKT)
Eric Liu explains why in his new book, he calls himself "Chinese American" -- without a hyphen.
July 11, 2014 -- Updated 1512 GMT (2312 HKT)
John Bare says hands-on learning can make a difference in motivating students to acquire STEM skills.
July 11, 2014 -- Updated 1320 GMT (2120 HKT)
Karl Alexander and Linda Olson find blacks and whites live in urban poverty with similar backgrounds, but white privilege wins out as they grow older.
July 10, 2014 -- Updated 1620 GMT (0020 HKT)
Frida Ghitis says a poll of 14 Muslim-majority nations show people are increasingly opposed to extremism.
July 10, 2014 -- Updated 1828 GMT (0228 HKT)
Ruben Navarrette says spending more on immigation enforcement isn't going to stop the flow of people seeking refuge in the U.S.
July 10, 2014 -- Updated 2048 GMT (0448 HKT)
Faisal Gill had top security clearance and worked for the Department of Homeland Security. That's why it was a complete shock to learn the NSA had him under surveillance.
July 10, 2014 -- Updated 1841 GMT (0241 HKT)
Kevin Sabet says the scientific verdict is that marijuana can be dangerous, and Colorado should be a warning to states contemplating legalizing pot.
July 9, 2014 -- Updated 2047 GMT (0447 HKT)
World War I ushered in an era of chemical weapons use that inflicted agonizing injury and death. Its lethal legacy lingers into conflicts today, Paul Schulte says
July 10, 2014 -- Updated 1137 GMT (1937 HKT)
Tom Foley and Ben Zimmer say Detroit's recent bankruptcy draws attention to a festering problem in America -- cities big and small are failing to keep up with change.
July 10, 2014 -- Updated 1201 GMT (2001 HKT)
Mel Robbins says many people think there's "something suspicious" about Leanna Harris. But there are other interpretations of her behavior
July 9, 2014 -- Updated 1753 GMT (0153 HKT)
Amy Bass says Germany's rout of Brazil on its home turf was brutal, but in defeat the Brazilian fans' respect for the victors showed why soccer is called 'the beautiful game'
July 9, 2014 -- Updated 2107 GMT (0507 HKT)
Aaron Carroll explains how vaccines can prevent illnesses like measles, which are on the rise
July 9, 2014 -- Updated 0008 GMT (0808 HKT)
Aaron Miller says if you think the ongoing escalation between Israel and Hamas over Gaza will force a moment of truth, better think again
July 8, 2014 -- Updated 1903 GMT (0303 HKT)
Norman Matloff says a secret wage theft pact between Google, Apple and others highlights ethics problems in Silicon Valley.
July 8, 2014 -- Updated 2237 GMT (0637 HKT)
The mother of murdered Palestinian teenager Mohammed Abu Khder cries as she meets Palestinian president Mahmoud Abbas in Ramallah, West Bank on July 7, 2014.
Naseem Tuffaha says the killing of Israeli teenagers has rightly brought the world's condemnation, but Palestinian victims like his cousin's slain son have been largely reduced to faceless, nameless statistics.
ADVERTISEMENT