CORVALLIS, Ore. - The warming of Earth’s climate threatens to increase global food insecurity and halt more than two decades of progress toward curbing global hunger, according to a major assessment by 31 researchers.
Worldwide, climate change is likely to destabilize cropping systems, interrupt transportation networks and trigger food shortages and price hikes, says the report, unveiled last week by U.S. agriculture secretary Tom Vilsack at the UN’s COP-21 climate conference in Paris.
While the pace of these changes depends on a multitude of factors, their effects will become more pronounced by mid-century, the researchers found. Under the least optimistic scenario—based on high carbon emissions and low international cooperation—agricultural yields could go down by as much as 15 percent and food prices could rise more than 30 percent by 2050.
“A lot has been written about the impacts of climate change on agriculture in developing countries,” said John Antle, an agricultural economist in the College of Agricultural Sciences at Oregon State University who led the study’s socioeconomic modeling.
“What’s different about this study is that it brings the impact of food insecurity home to the United States,” Antle said.
While developing countries, particularly in tropical regions, will suffer the most, the United States - the world’s largest exporter of food - will also feel the shocks, he said. Hunger is not expected to rise in the world’s richest country, but climate-driven changes are expected to lower long-term agricultural productivity, with an impact on a major sector of the U.S. economy.
Climate is, of course, the most important influence on agriculture. The crops in various regions of the world are adapted to particular regimes of temperature, season length and rainfall. When those parameters change with a changing climate, agricultural systems are disrupted.
What’s less recognized, say the researchers, is that climate change also disrupts global systems for transporting, storing, packaging and delivering food, making it harder for people to get enough of the right kind of food, especially in regions that already are food-insecure.
The percentage of the world’s undernourished people has been cut nearly in half since 1990-91, from 19 percent to 11 percent, according to the U.N.’s Food and Agriculture Organization.
“The challenge we now face,” Vilsack said in a statement, “is whether we can maintain and even accelerate this progress despite the threats from climate change.”
Earth’s climate is getting warmer because of increased carbon dioxide and other “greenhouse” gases in the atmosphere. Two hundred years ago the atmosphere held about 280 parts per million of carbon dioxide. Now it holds about 400 parts per million, and as a result, Earth’s average temperature has risen about 0.8 degrees C (1.4 degrees F).
The report reviews and synthesizes recent research by global and regional modeling teams that projects impacts of climate change on agricultural production, consumption, prices and trade.
One of these teams is the Agricultural Model Intercomparison and Improvement Project. Antle is a co-leader of that project, which uses detailed regional data to assess the vulnerability of poor rural populations to economic disruptions linked to climate. Antle leads the project’s regional economic assessment teams in Africa and South Asia.
“These assessments have helped us develop a range of plausible outcomes from the variety of responses to different levels of climate change,” Antle said.
“Agriculture has adapted to various shifts in climate over time, but I think the concern now is how rapidly things are changing,” he said. “We have a growing global population and increasing pressure on water, soil and other resources. Even without climate change, feeding the world would likely get harder.”
The researchers also said that appropriate technological, economic and policy decisions could greatly mitigate the destabilizing effects of climate.
“Climate Change, Global Food Security and the U.S. Food System” is the result of a 3-year study commissioned by the U.S. Department of Agriculture as part of President Obama’s Climate Action Plan. Its 31 contributors represent universities and other research institutions in four countries.
The Paris climate conference continues through Friday, Dec. 11.