Featured Research

from universities, journals, and other organizations

Crops Feel The Heat As The World Warms

Date:
March 16, 2007
Source:
Carnegie Institution
Summary:
Over a span of two decades, warming temperatures have caused annual losses of roughly $5 billion for major food crops, according to a new study. Researchers provide documentation that this decline is due to increases in global temperatures.

Over a span of two decades, warming temperatures have caused annual losses of roughly $5 billion for major food crops, according to a new study by researchers at the Carnegie Institution and Lawrence Livermore National Laboratory.

From 1981-2002, warming reduced the combined production of wheat, corn, and barley--cereal grains that form the foundation of much of the world's diet--by 40 million metric tons per year. Researchers provide documentation that this decline is due to increases in global temperatures.

"Most people tend to think of climate change as something that will impact the future," said Christopher Field, co-author on the study and director of Carnegie's Department of Global Ecology in Stanford, Calif. "But this study shows that warming over the past two decades has already had real effects on global food supply."

The study is the first to estimate how much global food production has already been affected by climate change. Field and David Lobell, lead author of the study and a researcher at Lawrence Livermore National Laboratory, compared yield figures from the Food and Agriculture Organization with average temperatures and precipitation in the major growing regions.

They found that, on average, global yields for several of the crops responded negatively to warmer temperatures, with yields dropping by about 3-5 percent for every 1 degree F increase. Average global temperatures increased by about 0.7 degrees F during the study period, with even larger changes in several regions.

"Though the impacts are relatively small compared to the technological yield gains over the same period, the results demonstrate that negative impacts are already occurring," said Lobell.

The researchers focused on the six most widely grown crops in the world: wheat, rice, maize (corn), soybeans, barley and sorghum--a genus of about 30 species of grass raised for grain. These crops occupy more than 40 percent of the world's cropland, and account for at least 55 percent of non-meat calories consumed by humans. They also contribute more than 70 percent of the world's animal feed.

The main value of this study, the authors said, was that it demonstrates a clear and simple correlation between temperature increases and crop yields at the global scale. However, Field and Lobell also used this information to further investigate the relationship between observed warming trends and agriculture.

"We assumed that farmers have not yet adapted to climate change--for example, by selecting new crop varieties to deal with climate change. If they have been adapting--something that is very difficult to measure--then the effects of warming may have been lower," explained Lobell.

Most experts believe that adaptation would lag several years behind climate trends, because it can be difficult to distinguish climate trends from natural variability. "A key moving forward is how well cropping systems can adapt to a warmer world. Investments in this area could potentially save billions of dollars and millions of lives," Lobell added.

The study will be published March 16 in the online journal Environmental Research Letters.


Story Source:

The above story is based on materials provided by Carnegie Institution. Note: Materials may be edited for content and length.


Cite This Page:

Carnegie Institution. "Crops Feel The Heat As The World Warms." ScienceDaily. ScienceDaily, 16 March 2007. <www.sciencedaily.com/releases/2007/03/070316072609.htm>.
Carnegie Institution. (2007, March 16). Crops Feel The Heat As The World Warms. ScienceDaily. Retrieved July 23, 2014 from www.sciencedaily.com/releases/2007/03/070316072609.htm
Carnegie Institution. "Crops Feel The Heat As The World Warms." ScienceDaily. www.sciencedaily.com/releases/2007/03/070316072609.htm (accessed July 23, 2014).

Share This




More Earth & Climate News

Wednesday, July 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

New Orleans Plans to Recycle Cigarette Butts

New Orleans Plans to Recycle Cigarette Butts

AP (July 21, 2014) New Orleans is the first U.S. city to participate in a large-scale recycling effort for cigarette butts. The city is rolling out dozens of containers for smokers to use when they discard their butts. (July 21) Video provided by AP
Powered by NewsLook.com
Shark Sightings a Big Catch for Cape Tourism

Shark Sightings a Big Catch for Cape Tourism

AP (July 21, 2014) A rise in shark sightings along the shores of Chatham, Massachusetts is driving a surge of eager vacationers to the beach town looking to catch a glimpse of a great white. (July 21) Video provided by AP
Powered by NewsLook.com
Spectacular Lightning Storm Hits London

Spectacular Lightning Storm Hits London

AFP (July 19, 2014) A spectaCular lightning storm struck the UK overnight Friday. Images of lightning strikes over the Shard and Tower Bridge in central London. Duration: 00:23 Video provided by AFP
Powered by NewsLook.com
A Centuries' Old British Tradition Is Far from a Swan Song

A Centuries' Old British Tradition Is Far from a Swan Song

AFP (July 19, 2014) As if it weren't enough that the Queen is the Sovereign of the UK and 15 other Commonwealth realms, she is also the owner of all Britain's unmarked swans. Duration: 02:18 Video provided by AFP
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:
from the past week

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