VOA标准英语2010年-Russia's Damaged Wheat: a Glimpse of t

Experts say it may be the latest warning of how climate change in some key farming regions could threaten world food supplies.

In the new study in the Proceedings¹ of the National Academy of Sciences, researchers examined six years of data from 227 farms in six major rice-producing countries in Asia. They looked at how rice production varied² depending on the weather, and extrapolated those effects over the past quarter-century.

They found that "higher nighttime temperatures lead to lower yield," says lead author Jarrod Welch at the University of California, San Diego (UCSD).

Hot nights in Louisiana

In the southern U.S. state of Louisiana, the nation's third-largest producer of rice, hot nighttime temperatures have made the plants susceptible³ to a bacterial⁴ disease. Rice farmer Clarence Berken says yields are off by 25 to 30 percent in some of his fields.

"Especially in a year like this year, when [the price] for our crop is about half of what it was two years ago, and input⁵ costs have basically stayed the same," he says, "it's really something that's worrisome."

There may be more to worry about in the future for Berken and rice farmers around the world, because nighttime temperatures are predicted to rise faster with climate change than daytime temperatures. Welch says the negative impact on productivity could make rice more expensive in the future.

"The numbers of people that depend on rice are astronomical," he says. "Something like 3 billion people eat rice every day. Six hundred million or so depend on it as their staple⁶ food. And those 600 million are among the world's poorest billion."

All major crops affected⁷

Rice consumers aren't the only ones put at risk by rising temperatures. Last fall, another major study looking at U.S. maize⁸, soybean and cotton production showed that yields go down for each day a crop is exposed to temperatures above a certain threshold. Depending on how fast the climate warms this century, the study predicted crop yield declines from 30 to 80 percent.

 

A view of a wheat field dried-out after weeks of searing heat and practically no rain in Voronezh region, south of Moscow, 02 Aug 2010

The current run-up in wheat prices caused by Russia's heat-damaged harvest may be a glimpse into the future, according to Lester Brown, head of the Washington-based think tank, the Earth Policy Institute. 

"This has been sort-of a textbook lesson in the effect of rising temperature on grain yields," he says. "If you're an agronomist⁹, if you're someone concerned about future food security, you have to worry about that projected possible rise in temperature."

Weather cycle

But many U.S. farmers like Clarence Berken in Louisiana are not convinced that we're headed for a hotter future.

"We've had heat waves in the past, and that will come and go," he says. "I think it's more cyclical than anything else."

He adds that whatever the future holds, the Louisiana State University research station is constantly developing new rice varieties that help him adapt to changing conditions.

"It used to take 10 years to come out with a variety. And now we've cut that basically in half," he adds. "The research station does an excellent job of doing those kinds of things that basically have kept us in business."

"There are limits"

Research into improving crop yields has always been the key to meeting the world's food needs, says Nina Fedoroff, a plant scientist at Penn State University and former advisor¹⁰ to the U.S. State Department.

But she says it's unequivocal that the climate is getting hotter, and "there are limits to what our current crops can do."

She says today's commercial crops have evolved in a temperate¹¹ climate and there is only so much breeders can do to adapt them to a hotter, drier environment.

"The breeding for drought resistance, for example, will not create crops that are significantly more productive than the ones we have today. They will be crops that suffer less of a beating when there's a spell of high temperature," she says.

Scientists will need to create crops that are significantly more productive because the world's population is expected to grow nearly 50 percent by mid-century. Fedoroff says major changes – perhaps including the introduction of entirely¹² new crops and methods of production – will be needed to meet the challenges.

Scientists have made huge productivity gains before, and they could do it again. But Fedoroff notes that despite the urgent needs, crop research remains¹³ seriously underfunded.

"In principle, the doom¹⁴ and gloom doesn't have to happen," she says. "In practice, will we actually rearrange our priorities enough to prevent it? I don't know."

1 proceedings   

n.进程，过程，议程；诉讼(程序)；公报

参考例句：

• He was released on bail pending committal proceedings. 他交保获释正在候审。
• to initiate legal proceedings against sb 对某人提起诉讼

2 varied   

adj.多样的，多变化的

参考例句：

• The forms of art are many and varied.艺术的形式是多种多样的。
• The hotel has a varied programme of nightly entertainment.宾馆有各种晚间娱乐活动。

3 susceptible   

adj.过敏的，敏感的；易动感情的，易受感动的

参考例句：

• Children are more susceptible than adults.孩子比成人易受感动。
• We are all susceptible to advertising.我们都易受广告的影响。

4 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。

5 input   

n.输入(物)；投入；vt.把(数据等)输入计算机

参考例句：

• I will forever be grateful for his considerable input.我将永远感激他的大量投入。
• All this information had to be input onto the computer.所有这些信息都必须输入计算机。

6 staple   

n.主要产物，常用品，主要要素，原料，订书钉，钩环；adj.主要的，重要的；vt.分类

参考例句：

• Tea is the staple crop here.本地产品以茶叶为大宗。
• Potatoes are the staple of their diet.土豆是他们的主要食品。

7 affected   

adj.不自然的，假装的

参考例句：

• She showed an affected interest in our subject.她假装对我们的课题感到兴趣。
• His manners are affected.他的态度不自然。

8 maize   

n.玉米

参考例句：

• There's a field planted with maize behind the house.房子后面有一块玉米地。
• We can grow sorghum or maize on this plot.这块地可以种高粱或玉米。

9 agronomist   

n.农学家

参考例句：

• The agronomist suggested growing rice on the dried river bed.那位农学家建议在干涸的河床上种水稻。
• She has elected to become an agronomist.她决心做一个农学家。

10 advisor   

n.顾问，指导老师，劝告者

参考例句：

• They employed me as an advisor.他们聘请我当顾问。
• The professor is engaged as a technical advisor.这位教授被聘请为技术顾问。

11 temperate   

adj.温和的，温带的，自我克制的，不过分的

参考例句：

• Asia extends across the frigid,temperate and tropical zones.亚洲地跨寒、温、热三带。
• Great Britain has a temperate climate.英国气候温和。

12 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

13 remains   

n.剩余物，残留物；遗体，遗迹

参考例句：

• He ate the remains of food hungrily.他狼吞虎咽地吃剩余的食物。
• The remains of the meal were fed to the dog.残羹剩饭喂狗了。

14 doom   

n.厄运，劫数；v.注定，命定

参考例句：

• The report on our economic situation is full of doom and gloom.这份关于我们经济状况的报告充满了令人绝望和沮丧的调子。
• The dictator met his doom after ten years of rule.独裁者统治了十年终于完蛋了。