Planting trees might not be such a good idea in the fight against global warming—least not in high latitudes (纬度). That’s the im

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问题     Planting trees might not be such a good idea in the fight against global warming—least not in high latitudes (纬度). That’s the implication of new research that finds that forests in parts of Canada, Siberia, and Scandinavia could absorb enough sunlight to warm those areas some 10 degrees Fahrenheit (5.5 degree Celsius) over the next century compared to if those forests don’t exist. They run counter to long-standing arguments that planting trees anywhere in the world is an effective way to combat global warming. The new study supports the practice in rain forest zones, where more trees absorb more carbon dioxide from the atmosphere. Tropical plants also produce more water vapor, adding to the thick cloud cover that reflects sunlight back into space. But the dark canopies(树冠) of northern forests absorb the sun’s rays and cover the snow that would reflect light, creating a  regional warming effect.
    "If you look down from an airplane, where you have seasonal snow cover and you don’t have a forest, it’s all white, and that snow is highly reflective," said study co-author Govindasamy Bala, an atmospheric scientist at Lawrence Livermore National Laboratory. "If you plant new trees, the canopy covers that snow and very little sunlight is reflected. That’s why when you plant trees there is a potential for locally warming a place."
    Forest preservation and reforestation efforts are still critical for lessening global warming, Bala and colleagues caution. But "our first hypothesis was that the benefit of planting trees cannot be uniform everywhere". In addition to their conclusion about northern forests, the team found that planting more trees in mid-latitude locales-including most of the United States and Europe—may have little effect on climate change.
    "Planting trees in the tropics gives you the maximum benefit if you want to slow down global warming," said Bala, "From the perspective of biodiversity and conservation, tropical forests are the most biologically important real estate anywhere." So from that perspective it’s good news to highlight efforts for protecting those forests.
    Bala’s team notes that their research is only a first step toward understanding the roles of forests in complex climatic processes. They also stress that widespread deforestation would cause ecological destruction and is not a feasible option for keeping global warming in check. "The destruction of ecosystems(生态系统) to prevent global  warming," the team wrote in their paper, "would be a counterproductive and ridiculous strategy."

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答案planting trees in high latitudes

解析 由于题干中关键词different to the traditional idea与文中counter to long-standing arguments相呼应,可定位到原文首段第三句They run counter to long-standing arguments that planting trees anywhere in the world is an effective way to combat global warming.(这与长久以来人们认为的在世界任何地方植树都会有利地反击全球变暖的观点相左。)根据上下文的指代关系,可知,本句中的they即指文章首句Planting trees might not be such a good idea in the fight against global warming—at least not in high latitudes,根据题干的语法要求,可得答案。
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