A new study shows that rising levels of planet-warming gasses may reduce important nutrients in food crops.
Other studies have shown that higher temperatures from climate change and weather extremes will reduce food production. But scientists are finding that rising levels of carbon dioxide and other planet-warming gasses threaten food quality.
Researchers studied the effects of one such gas- carbon dioxide-on rice. They grew 18 kinds of rice in fields in China and Japan in a controlled environment. They set carbon dioxide levels to what scientists are predicting for our planet by the end of the century. They found that the resulting rice crops had lower than normal levels of vitamins, minerals and protein.
Rice grown under high carbon dioxide conditions had, on average, 13 to 30 percent lower levels of four B vitamins and 10 percent less protein. The crops also had 8 percent less iron and 5 percent less zinc (锌) than rice grown under normal conditions.
The researchers said the effects of planet-warming gasses would be most severe for the poorest citizens in some of the least developed countries. These people generally eat the most rice and have the least complex diets, they noted. Scientists estimated that almost 150 million people might be at risk of having too little protein or zinc in their diet by 2050.
One scientist, Sam Myers of Harvard University of Massachusetts, US, said that findings like this are an example of the surprises climate change creates. "My concern is, there are many more surprises to come, "he said.
Myers noted that pollution, loss of some species, destruction of forests, and other human activities are likely to produce unexpected problems. He said that you cannot completely change all the natural systems that living organisms have grown to depend on over millions of years without having effects come back to affect our own health.
The new study suggests a way to lower the nutritional harm of climate change-to grow different forms of rice that have shown to be more resistant to higher carbon dioxide levels.