A commonplace observation of weather fluctuating between a severe heat wave and a fairly cool day may be what dooms us to climat

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问题     A commonplace observation of weather fluctuating between a severe heat wave and a fairly cool day may be what dooms us to climate catastrophe, in two ways. On one side, the variability of temperatures from day to day and year to year makes it easy to miss, ignore or obscure the longer-term upward trend. On the other, even a fairly modest rise in average temperatures translates into a much higher frequency of extreme events — like the devastating drought now gripping America’s heartland — that do vast damage.
    Then how should we think about the relationship between climate change and day-to-day experience? Almost a quarter of a century ago James Hansen, the NASA scientist who did more than anyone to put climate change on the agenda, suggested the analogy of loaded dice. Imagine, he and his associates suggested, representing the probabilities of a hot, average or cold summer by historical standards as a die with two faces painted red, two white and two blue. By the early 21st century, they predicted, it would be as if four of the faces were red, one white and one blue. Hot summers would become much more frequent, but there would still be cold summers now and then. And so it has proved.
    But that’s not all: really extreme high temperatures, the kind of thing that used to happen very rarely in the past, have now become fairly common. Think of it as rolling two sixes, which happens less than 3 percent of the time with fair dice, but more often when the dice are loaded. And this rising incidence of extreme events, reflecting the same variability of weather that can obscure the reality of climate change, means that the costs of climate change aren’t a distant prospect, decades in the future. On the contrary, they’re already here, even though so far global temperatures are only about 1 degree Fahrenheit above their historical norms, a small fraction of their eventual rise if we don’t act.
    The great Midwestern drought is a case in point. This drought has already sent corn prices to their highest level ever. If it continues, it could cause a global food crisis, because the U. S. heartland is still the world’s breadbasket. And yes, the drought is linked to climate change: such events have happened before, but they’re much more likely now than they used to be. Now, maybe this drought will break in time to avoid the worst. But there will be more events like this.
    Will the current drought finally lead to serious climate action? History isn’t encouraging. The deniers will surely keep on denying, especially because conceding at this point that the science they’ve trashed was right all along would be to admit their own culpability for the looming disaster. And the public is all too likely to lose interest again the next time the dice comes up white or blue.
The great Midwestern drought is mentioned in Paragraph 4 to show______.

选项 A、its connection to global food crises
B、its causal linkage to climate change
C、the urgent need for climate action
D、the rising occurrence of weather extremes

答案B

解析 解答此题关键在了解第三、四段间关系。第三段指出极端事件发生频率上升,即气候变化代价的已然发生。紧接着第四段以中西部大旱所带来的危害为例加以证明,可见[B]选项正确。
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