题型：阅读理解 题类：模拟题 难易度：普通
上海市崇明区2019届高三英语第二次模拟考试试卷（音频暂未更新）
The Earth is facing a climate crisis, but it's also getting greener and leafier. According to new research, the rise is largely due to China and India.
A study by National Aeronautics and Space Administration (NASA), based on extensive satellite photographs and published in the journal Nature Sustainability, has revealed that the two countries with the world's biggest populations are also responsible for the largest increase in greenness.
Since 2000, the planet's green leaf area has increased by 5 percent, or over 2 million square miles. That's an area equivalent to the sum total of the Amazon rainforests, NASA says. But researchers stressed that the new greenery does not neutralize deforestation and its negative impacts on ecosystems elsewhere.
A third of the leaf increase is thanks to China and India, due to the implementation of major tree-planting projects alongside a vast increase in agriculture.
Using the data from a NASA sensor, researchers discovered that China is the source of a quarter of the increase in green leaf area, despite possessing only 6.6 percent of the world's vegetated area (植被区). Forests account for 42 percent of that increase, while croplands make up a further 32 percent. China's increase in forest area is the result of forest preservation and expansion programs, NASA said, established to fight against the impacts of climate change, air pollution and soil erosion (水土流失). India has contributed a further 6.8 percent rise in green leaf area, with 82 percent from croplands and 4.4 percent from forests.
Rama Nemani, a co-author of the study and a researcher at NASA's Ames Research Center, said in a statement, "When the greening of the Earth was first observed, we thought it was due to a warmer, wetter climate and fertilization from the added carbon dioxide in the atmosphere, leading to more leaf growth in northern forests, for instance." "Now, with the data that lets us understand the phenomenon at really small scales, we see that humans are also contributing," Nemani said. "This will help scientists make better predictions about the behavior of different Earth systems, which will help countries make better decisions about how and when to take action."
Thomas Pugh, a professor at the University of Birmingham's School of Geography, Earth and Environmental Sciences, said the NASA report expands scientists' understanding of the causes behind global greening. But he also cautioned that a direct line cannot be drawn between an increase in global greening and a decrease in negative impacts of climate change.
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