题型:阅读理解 题类:常考题 难易度:普通
湖北省襄阳市2017-2018学年高二下学期英语期末考试试卷
A new study shows that rising levels of planet-warming gases may reduce important nutrients in food crops.
Researchers studied the effects of one such gas—carbon dioxide—on rice. The researchers grew rice plants 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. The researchers said the effects of planet-warming gases 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.
In the experiment, scientists grew 18 kinds of rice in fields in China and Japan. They pumped carbon dioxide gas over the plants in an effort to create the atmosphere of the future. 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)an rice grown under normal conditions. However, vitamin E levels increased by about 13 percent on average.
The results are bad news, “especially for the nutrition of the poorer population in less-developed countries,” said the University of Tokyo's Kazuhiko Kobayashi, who helped to write the report. That includes about 600 million people in Indonesia, Cambodia, Myanmar, Bangladesh, Laos and other nations, mainly in Southeast Asia, the report said.
One of the scientists is Sam Myers of Harvard University in the American state of Massachusetts. He said that findings like this are an example of the surprises climate change create. “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. One way, Kobayashi said, is grow different forms of rice that have shown to be more resistant to higher carbon dioxide levels.
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