New Issue: Orbital Catastrophe Ahead? Read Now

Experts Warn Climate Change Is Beginning to Disrupt Agriculture

With the added environmental stresses of climate change, prices of staple crops could double

Join Our Community of Science Lovers!

Every nation -- developed and otherwise -- is dependent upon a stable agricultural sector, and climate change threatens that stability, a panel of experts said yesterday.

World population is expected to swell by 50 percent by 2050. This alone is a challenge for the world's supply of vital grains, said Gerald Nelson, an agricultural economist and fellow at the International Food Policy Research Institute. But then you have to tack on the impacts of climate change.

The price of major grains like rice and wheat were already projected to also increase by roughly 50 percent by 2050, Nelson said. With the added environmental stresses expected of climate change, prices could instead double, according to IFPRI.


On supporting science journalism

If you're enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.


Global agriculture, he said, could adapt to climate change for about $7 billion annually, with most of the resources being devoted to research, new irrigation techniques and training small farmers for rises in sea level.

Agricultural management directly affects how the three major greenhouse gases -- carbon dioxide, methane and nitrous oxide -- are cycled through the environment. According to United Nations Environment Programme, "Agriculture, deforestation and other forms of land use account for nearly one-third of global greenhouse gas emissions."

The four-member panel was organized by the American Association for the Advancement of Science with support, the host noted, from Sen. Tom Harkin (D-Iowa). Panelists stressed the need for funding aimed at mitigating the damage to agricultural resources around the world potentially affected by climate change.

Accelerating cycles of drought and rain
Climate variability has already affected rains, droughts and temperatures in several parts of the United States, said Cynthia Rosenzweig, a senior research scientist with NASA's Goddard Institute for Space Studies. "We are already seeing climate change."

"We are seeing the expansion of drying," said Rosenzweig, as she brought up a slide showing precipitation measurements across the United States. The measurements, comparing values from 1958 through 2008, showed significant reductions in rainfall across large portions of the Northwest and Southeast. Idaho, Washington, Montana, Georgia and Florida had some of the most drastic changes in rainfall on the map.

However, the opposite is not good either, she said, adding that increased soil moisture in some areas could potentially harbor insects and other pests. And, in general, "crops do not like to have their feet wet."

Aside from concerns about rainfall, local temperature is also extremely important for crop performance.

The reproductive development in many important grains is a process sensitive to temperature, said Paul Gepts, a professor of agronomy at the University of California, Davis.

Some plants need cold winters
One of the potential side effects of climate change is a trend toward milder winters in some regions. Vital plants, Gepts said, require a cold winter in order to properly develop their seeds for the next season.

Rosenzweig agreed. Heat waves, at odd times of the year, affect the proper development of proteins within corn kernels, she said. "It is like scrambling eggs."

Gepts also presented a number of well-known strategies for mitigating some of the possible economic effects of climate change on agriculture. Aside from breeding plants to be more drought-, heat- and pest-resistant, he also suggested varying the types of crops maintained on a particular site on the basis of environmental suitability.

Should the a region experience a heat wave or extreme frost, Gepts said, then perhaps only the crops intolerant to those temperatures may be lost for a season and not the entire farm, protecting farmers from complete financially devastation.

Each member of the panel, which also included R. Cesar Izaurralde, a fellow at the Joint Global Change Research Institute, reaffirmed the belief that ripples in agricultural stability inevitably lead to civil unrest and a substantial threat to national security.

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500

Subscribe to Support Independent Journalism

Great science journalism requires human expertise, time, effort and creativity. And it costs money. That’s why I and the journalists here at Scientific American hope you’ll join our community.

When you subscribe, you are supporting staff and freelance journalists who are passionate about telling science stories that are true, important and compelling. Our editors and reporters are often experts in their fields, which means they understand the nuances of big discoveries and can untangle the breakthroughs from the hype. With a subscription, you are also supporting rigorous fact-checking to ensure the words we publish are precise and accurate. And you’re supporting original illustrations, graphics and photos that bring you closer to an advanced laboratory, an ice sheet in Antarctica or a space mission in orbit. You’re helping us craft other types of high-quality journalism as well: Our newsletters are carefully written, edited and curated by staffers you have or will come to know and love. Our Science Quickly podcast is based on original reporting, collaboration with editors and scientists and exacting production.

Subscriptions keep this engine running so we can continue to deliver thoughtful, rigorous and independent science journalism to you. In an era of viral misinformation, this work is crucial. If you value what we do, I hope you’ll consider joining us as a subscriber

Thank you,

Jeanna Bryner, Editor in Chief, Scientific American

Subscribe