VOA慢速英语:Study Links Climate Change to Changes in Crop Yields

A new study says climate change has reduced the world's wheat and maize production. The study says rice and soybean yields have also decreased in some places -- but increased in others. In the words of the researchers: "For soybeans and rice, winners and losers largely balanced out."
一项新的研究发现气候变化已经降低全世界小麦和玉米的产量。研究还称大米和大豆产量在某些地方也降低了——而另外一些地方却在增加。正如研究人员所说：“对于大米和大豆，产量增加的和产量减少的很大程度上互相抵消。”

The researchers studied climate trends and global crop production from between nineteen eighty and two thousand eight. They found that climate changes "are already exerting a considerable drag on yield growth" and may have affected food prices.
研究人员研究了1980——2008年间气候趋势和全球作物产量的关系。他们发现气候变化“巨大地阻碍作物产量的增长”，可能已经影响食品价格。

The study used computer models linking crop yields to weather. Yield is the amount produced for each hectare or acre. The researchers compared the results to what the yields might have been without climate changes. They found that corn production decreased by almost four percent and wheat production decreased by five and a half percent.
研究利用计算机模型将作物产量跟气候联系起来。产量是每公顷或每英亩生产的数量。研究人员把结果跟气候没有变化地区的作物产量相比。他们发现，玉米产量减少了约4%，而小麦产量减少了5.5%。

Warming temperatures were reported in almost all of Europe, much of Asia and some of South America and Africa. During the study period most countries had greater temperature changes from year to year than they have had historically. But the study says the United States was an important exception -- at least so far.
几乎所有欧洲地区，大部分亚洲地区，部分南美地区和非洲地区都有报道气候变暖。在研究的这段期间，大部分国家每年的气候变化比历史上的气候变化更大。但是研究称，美国是一个特殊的例外——到目前为止气候变化最小。

Corn and wheat yields in most of North America remained about the same. Russia's wheat yields decreased the most. The largest loss in corn yields were in China and Brazil.
北美大部分地区的玉米和小麦产量依然保持不变。俄罗斯的小麦产量下降幅度最大。中国和巴西的玉米产量损失最大。

The report is in the journal Science.
报道发表在《科学》杂志上。

One of the researchers was economist Wolfram Schlenker at Columbia University in New York and the National Bureau of Economic Research. He says the report can serve as a planning tool for policy makers.
其中一名研究人员是来自纽约哥伦比亚大学和国家经济研究局的经济学家Wolfram Schlenker。他说这个报道可以作为决策者的规划工具。

WOLFRAM SCHLENKER: "If you are worried about rising food prices, it might be good to funnel some research into breeding for heat tolerance and maybe even drought tolerance."
Wolfram Schlenker：“如果你担心食品价格上涨，你可以集中进行育种耐暑性甚至耐旱性种类的作物研究。”

Jeffrey Stark is with a public policy organization called the Foundation for Environmental Security and Stability. This group is supported by the United States Agency for International Development. Mr. Stark recently described the effects of climate change on pastoralists in Uganda. They travel with their cattle to find grasslands and water.
Jeffrey Stark在国家政策机构——环境安全和稳定机构工作。这个团体受到美国国际开发署的支持。Mr. Stark最近描述了乌干达气候变化对牧民的影响。他们带着他们的牛到处找草原和水。

JEFFREY STARK: "We did hear repeatedly that there have been increasing temperatures, drying wetlands, less frequent but more intense rain, hail storms and, most significantly, uNPRedictable shifts in seasonal patterns. The pastoralists in the cattle corridor have to travel farther in search of pasture and water."
Jeffrey Stark：“我们的确一再听到气温在升高，湿地变干枯，较不频繁但更加密集的降水和冰雹风暴，最重要的是，季节模式的变化不可预测。这里的牧民们不得不把牛赶到更远的地方寻找草地和水。”

And that search, he says, can bring them into contact and conflict with farmers who have problems of their own.
他说，这种寻找会使他们跟有自身问题的农民进行接触和发生冲突。