Sugarcane can cool climate, study finds

     LOS ANGELES, April 18 (Xinhua) -- Sugarcane（甘蔗） has the effect of cooling temperatures(温度), thus playing role in stemming global warming, a new study has found.

    Sugarcane does so by reflecting sunlight back into space and by lowering the temperature of the surrounding air as the plants " exhale¹（呼出）" cooler water, according to the study conducted by researchers at the Carnegie Institution's Department of Global Ecology.

    The researchers used data from hundreds of satellite images over 733,000 square miles (about 1,173 square kilometers) in Brazil, where sugarcane is widely grown. They measured temperature, reflectivity (also called albedo), and evapotranspiration -- the water loss from the soil and from plants as they exhale water vapor².

    The findings showed that expansion of sugarcane in areas previously³ occupied by other Brazilian crops cools the local climate.

    Converting from natural vegetation to crop/pasture on average warmed the cerrado by 2.79 Fahrenheit⁴ (1.55 Centigrade, but that subsequent conversion⁵ to sugarcane, on average, cooled the surrounding air by 1.67 Fahrenheit (0.93 Centigrade), the researchers said in the study published in the April issue of Nature Climate Change.

    "We found that shifting from natural vegetation to crops or pasture results in local warming because the plants give off less beneficial water. But the bamboo-like sugarcane is more reflective and gives off more water -- much like the natural vegetation," said lead researcher Scott Loarie. "It's a potential win-win for the climate -- using sugarcane to power vehicles reduces carbon emissions⁶, while growing it lowers the local air temperature."Brazilians are world leaders in using biofuels for gasoline. About a quarter of their automobile⁷ fuel consumption comes from sugarcane, which significantly reduces carbon dioxide emissions that otherwise would be emitted from using gasoline.

    The researchers emphasized that the beneficial effects are contingent⁸ on the fact sugarcane is grown on areas previously occupied by crops or pastureland, and not in areas converted from natural vegetation. It is also important that other crops and pastureland do not move to natural vegetation areas, which would contribute to deforestation.

    So far most of the thinking about ecosystem⁹ effects on climate considers only impacts from greenhouse gas emissions. But according to co-researcher Greg Asner, "It's becoming increasingly clear that direct climate effects on local climate from land-use decisions constitute significant impacts that need to be considered core elements of human-caused climate change."（本文由在线英语听力室整理编辑）

1 exhale   

v.呼气，散出，吐出，蒸发

参考例句：

• Sweet odours exhale from flowers.花儿散发出花香。
• Wade exhaled a cloud of smoke and coughed.韦德吐出一口烟，然后咳嗽起来。

2 vapor   

n.蒸汽，雾气

参考例句：

• The cold wind condenses vapor into rain.冷风使水蒸气凝结成雨。
• This new machine sometimes transpires a lot of hot vapor.这部机器有时排出大量的热气。

3 previously   

adv.以前，先前（地）

参考例句：

• The bicycle tyre blew out at a previously damaged point.自行车胎在以前损坏过的地方又爆开了。
• Let me digress for a moment and explain what had happened previously.让我岔开一会儿，解释原先发生了什么。

4 Fahrenheit   

n./adj.华氏温度；华氏温度计(的)

参考例句：

• He was asked for the boiling point of water in Fahrenheit.他被问到水的沸点是华氏多少度。
• The thermometer reads 80 degrees Fahrenheit.寒暑表指出华氏80度。

5 conversion   

n.转化，转换，转变

参考例句：

• He underwent quite a conversion.他彻底变了。
• Waste conversion is a part of the production process.废物处理是生产过程的一个组成部分。

6 emissions   

排放物( emission的名词复数 )； 散发物（尤指气体）

参考例句：

• Most scientists accept that climate change is linked to carbon emissions. 大多数科学家都相信气候变化与排放的含碳气体有关。
• Dangerous emissions radiate from plutonium. 危险的辐射物从钚放散出来。

7 automobile   

n.汽车，机动车

参考例句：

• He is repairing the brake lever of an automobile.他正在修理汽车的刹车杆。
• The automobile slowed down to go around the curves in the road.汽车在路上转弯时放慢了速度。

8 contingent   

adj.视条件而定的；n.一组，代表团，分遣队

参考例句：

• The contingent marched in the direction of the Western Hills.队伍朝西山的方向前进。
• Whether or not we arrive on time is contingent on the weather.我们是否按时到达要视天气情况而定。

9 ecosystem   

n.生态系统

参考例句：

• This destroyed the ecosystem of the island.这样破坏了岛上的生态系统。
• We all have an interest in maintaining the integrity of the ecosystem.维持生态系统的完整是我们共同的利益。