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Studies have shown that higher temperatures from climate change an d weather extremes will r-educe food production.But scientists are finding that rising levels of carbon dioxide and other pla-net-warming gasses t hreaten food quality.

The researchers grew rice plants in a controlled environment.They se t carbon dioxide levels to what scientists are predicting for our planet b y the end of the century.They found that the resulting rice crops had lowe r than normal levels of vitarmins?minerals and prolein.The researchers said the effects of planet-warming gasses would be most severe for the po orest citizens in some of the least developed countries, mainly in Southea st Asia. These people generally eat the most rice and have the least com plex diet,they noted.Scientists estimated that almost 150 millionprople might be at risk of having little protein or zinc in their diet by 2050.

One of these scientists，Sam Myers of Harvard University in the Ame rican state of Massachusets, said the findings like this are an example o f the surprises climate change creates.“My concern is, there are many m ore 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 chan ge all the natural systems that living organisms have grown to depend o n over millions of years without having effects come back to affect our own health.

The new study suggests away to lower the nutritional harm of dim at echange. One way, Kobayashi said is to grow different forms of rice that have shown to be more resistant to higher carbon dioxide levels.