Climate change makes crops shrink

Income from the most important crops has fallen since 1981 due to the climate

Dried corn LLNL
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Global warming has long had an impact on food production: Every year 40 million tons less wheat, barley and maize are harvested worldwide due to increasing heat and drought, according to a recent study. Since 1981, climate-related crop losses for the main crops alone have amounted to around five billion US dollars.

"There is clearly a negative reaction of global yields to rising temperatures, " said David Lobell, researcher at the US Lawrence Livermore National Laboratory and lead author of the study. "Although the impacts are still relatively small compared to technology-related yields at the same time, the results clearly demonstrate that the adverse effects of climate change on crops are already occurring globally."

Warming is already having an effect

Lobell and his colleague Christopher Field, head of ecology at the Carnegie Institution, studied climate effects on six of the world's most widely grown crops: wheat, rice, corn, soybeans, barley, and sorghum. The combined production of these plants accounts for 40 percent of the world's acreage. The researchers compared the FAO's global yield figures with average temperatures and precipitation in their respective regions.

This study is the first to demonstrate whether and how much global food production is already affected by climate change. "Most people think of climate change as something that will affect the future. But this study shows that the warming of the past two decades has already had real effects on global food resources, "said Field.

Adjustments urgently needed

Average annual temperatures have risen by about 0.7 degrees between 1980 and 2002, in some regions even more. The scientists found that global yields on some crops were negative for warmer temperatures. According to the researchers, the significance of the study lies in the fact that at a global level, they clearly show a simple correlation between harvest losses of around three to five percent and a rise in temperature of around one degree. display

"One key to progress is the adaptability of plants to a warmer world, " explains Lobell. "Investing in this area could potentially save billions of dollars and save millions of lives." However, most experts predict that such adjustments will lag several years behind climate trends, as it is difficult to distinguish real climate trends from short-term "weather caprices",

(Lawrence Livermore National Laboratory, 19.03.2007 - NPO)