Featured Research

from universities, journals, and other organizations

Toll Of Climate Change On World Food Supply Could Be Worse Than Thought

Date:
December 4, 2007
Source:
Earth Institute at Columbia University
Summary:
Global agriculture, already predicted to be stressed by climate change in coming decades, could go into steep, unanticipated declines in some regions due to complications that scientists have so far inadequately considered, say three new scientific reports. The authors say that progressive changes predicted to stem from 1- to 5-degree C temperature rises in coming decades fail to account for seasonal extremes of heat, drought or rain, multiplier effects of spreading diseases or weeds, and other ecological upsets.

Parched ground cracks in a wheat field during the hot European summer of 2006.
Credit: iStockphoto/Susan Stewart

Global agriculture, already predicted to be stressed by climate change in coming decades, could go into steep, unanticipated declines in some regions due to complications that scientists have so far inadequately considered, say three new scientific reports. The authors say that progressive changes predicted to stem from 1- to 5-degree C temperature rises in coming decades fail to account for seasonal extremes of heat, drought or rain, multiplier effects of spreading diseases or weeds, and other ecological upsets. All are believed more likely in the future. Coauthored by leading researchers from Europe, North America and Australia, they appear in a recent issue of the Proceedings of the National Academy of Sciences (PNAS).

Related Articles


"Many people assume that we will never have a problem with food production on a global scale. But there is a strong potential for negative surprises," said Francesco Tubiello, a physicist and agricultural expert at the NASA/Goddard Institute of Space Studies who coauthored all three papers. Goddard is a member of Columbia University's Earth Institute.

In order to keep pace with population growth, current production of grain--from which humans derive two-thirds of their protein--will probably have to double, to 4 billion tons a years before 2100. Studies in the past 10 years suggest that mounting levels of carbon dioxide in the air--believed to be the basis of human-caused climate change--may initially bolster the photosynthetic rate of many plants, and, along with new farming techniques, possibly add to some crop yields.

Between now and mid-century, higher temperatures in northerly latitudes will probably also expand lands available for farming, and bring longer growing seasons. However, these gains likely will be canceled by agricultural declines in the tropics, where even modest 1- to 2-degree rises are expected to evaporate rainfall and push staple crops over their survival thresholds. Existing research estimates that developing countries may lose 135 million hectares (334 million acres) of prime farm land in the next 50 years. After mid-century, continuing temperature rises--5 degrees C or more by then--are expected to start adversely affecting northern crops as well, tipping the whole world into a danger zone.

The authors of the PNAS studies say that much of the previous work is oversimplified, and as a consequence, the potential for bigger, more rapid problems remains largely unexplored. "The projections show a smooth curve, but a smooth curve has never happened in human history," said Tubiello. "Things happen suddenly, and then you can't respond to them." For instance, extreme-weather events of all kinds, including heat waves or sudden big storms, could easily wipe out crops on vast scales if they occur for even a few days during critical germination or flowering times.

Tubiello says this is already happening on smaller scales. During a heat wave in the summer of 2003, temperatures in Italy soared 6 degrees C over their long-term mean, and the corn yield in the rich Po valley dropped a record 36%. Nearly all the world's pastures are rain-fed; in Africa, droughts in the 1980s and 1990s wiped out 20% to 60% of some nations' herds. Such events on larger scales could arise with little or no warning in the near future, the authors suggest.

Higher temperatures may also prompt outbreaks of weeds and pests, and affect plant or animal physiology--factors also left out of most projections. One of the new PNAS studies, "Crop and Pasture Response to Climate Change," says that more recent modeling suggests cattle ticks and bluetongue (a viral disease of sheep and cattle) will move outward from the tropics to areas such as southern Australia. Other new models suggest that higher temperatures will limit the ability of modern dairy-cow breeds to convert feed into milk, and lead to declines in livestock fertility and longevity. As temperatures rise in northerly latitudes, the ability of crop pests to survive winters is expected to improve, enabling them to attack spring crops in regions where they were previously kept at bay during this vulnerable time.

The authors say that farmers may temporarily mitigate some effects of changing climate by moving toward adaptations now. Adaptations already being considered or set up include regional climate-forecasting systems that enable farmers to switch to different crops or change the timing of plantings; introduction of new varieties or species that can withstand anticipated conditions; and improved flood-mitigation and water-storage facilities. One of the PNAS studies, "Adapting Agriculture to Climate Change," says that such adaptations might help tropical farmers cut damages wrought by rises of 1.5 to 3 degrees, and temperate-region farmers, damages from 1- to 2-degree rises. This would buy a few decades of time for nations to agree on ways to slow or reverse the warming itself. "After that, all the bets are off," said Tubiello.

The other authors are based at the Food and Agriculture Organization, in Rome; Austria's International Institute for Applied Systems Analysis; France's National Agronomy Research Institute; Australia's Commonwealth Scientific and Industrial Research Organization; Pennsylvania State University; Arizona State University; and Wageningen University in the Netherlands.


Story Source:

The above story is based on materials provided by Earth Institute at Columbia University. Note: Materials may be edited for content and length.


Cite This Page:

Earth Institute at Columbia University. "Toll Of Climate Change On World Food Supply Could Be Worse Than Thought." ScienceDaily. ScienceDaily, 4 December 2007. <www.sciencedaily.com/releases/2007/12/071203173031.htm>.
Earth Institute at Columbia University. (2007, December 4). Toll Of Climate Change On World Food Supply Could Be Worse Than Thought. ScienceDaily. Retrieved December 19, 2014 from www.sciencedaily.com/releases/2007/12/071203173031.htm
Earth Institute at Columbia University. "Toll Of Climate Change On World Food Supply Could Be Worse Than Thought." ScienceDaily. www.sciencedaily.com/releases/2007/12/071203173031.htm (accessed December 19, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Friday, December 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Navy Unveils Robot Fish

Navy Unveils Robot Fish

Reuters - Light News Video Online (Dec. 18, 2014) The U.S. Navy unveils an underwater device that mimics the movement of a fish. Tara Cleary reports. Video provided by Reuters
Powered by NewsLook.com
Kids Die While Under Protective Services

Kids Die While Under Protective Services

AP (Dec. 18, 2014) As part of a six-month investigation of child maltreatment deaths, the AP found that hundreds of deaths from horrific abuse and neglect could have been prevented. AP's Haven Daley reports. (Dec. 18) Video provided by AP
Powered by NewsLook.com
When You Lose Weight, This Is Where The Fat Goes

When You Lose Weight, This Is Where The Fat Goes

Newsy (Dec. 17, 2014) Can fat disappear into thin air? New research finds that during weight loss, over 80 percent of a person's fat molecules escape through the lungs. Video provided by Newsy
Powered by NewsLook.com
The Hottest Food Trends for 2015

The Hottest Food Trends for 2015

Buzz60 (Dec. 17, 2014) Urbanspoon predicts whicg food trends will dominate the culinary scene in 2015. Mara Montalbano (@maramontalbano) has the story. Video provided by Buzz60
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:

Strange & Offbeat Stories


Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins