More than 5,450 square kilometres have burned across California in the past two weeks, as firefighters continue to battle some of the state’s worst wildfires. Meanwhile, the southern states of the US have experienced their first devastating hurricane this year.
The California fires include some that rank among the largest ever seen in the state. They followed a heatwave that caused blackouts, with Death Valley National Park hitting 54.4℃ in August, the highest temperature ever recorded on Earth.
“Exceptionally hot weather over the past two weeks certainly played an important role in drying out vegetation to this extreme degree,” says Daniel Swain at the University of California, Los Angeles. But the drying of fuel also started earlier, he notes. Last winter was dry in north California, and spring brought heatwaves.
There are several unusual aspects to the current fires. They expanded dramatically in the absence of the usual driver for large and fast-moving fires in the state: powerful, dry winds. “That makes the enormous area burned in such a short time all the more astonishing, since they’re essentially spreading on account of their own intensity,” says Swain.
The ignition (点火) of fires by dry lightning is also rare for the region, says Stephen Pyne at Arizona State University. He says this is California’s fourth major fire year in a row, when historically the state has seen between seven and 12 years between big fire seasons.
In the Gulf of Mexico, it is severe hurricanes that are the problem. Hurricane Laura made landfall in the US on Thursday 27 August amid official warnings of an “unsurvivable” storm surge (风暴潮), widespread flooding and catastrophic wind damage.
The storm is the first of four hurricanes in the Atlantic this year. About four-fifths of oil and gas production in the Gulf of Mexico has been shut down. The energy heartland of the south-western US was previously battered by Hurricane Harvey in 2017. Researchers later found that the heavy rainfall from the storm was made three times more likely by climate change.
Climate change is almost certainly at work in California too. “It is perfectly clear that climate change is increasing the likelihood and intensity of heatwaves in California,” says Swain.
Although the California Department of Forestry and Fire Protection had 14,000 people fighting the fires, observers say it is impossible to have enough crews to stop fires this big.
Authorities last month agreed a five-year plan to do just that. With climate change locked in for the next 30 years, the long-term answer is to reduce carbon emissions (碳排放), says Thomas Smith at the London School of Economics.
28. What is unusual about the current California fires?
A.They are driven by powerful winds. |
B.Dry lightning contributes partly to the fires. |
C.They started from north California last winter. |
D.Death Valley National Park is affected most seriously. |
29. How severe is Hurricane Laura in the Gulf of Mexico?
A.It has affected oil and gas production. |
B.It is as big as Hurricane Harvey in 2017. |
C.It is the fourth strongest in the Atlantic this year. |
D.It brings unsurvivable natural disasters to the area. |
30. What is a headache for California?
A.The fires may last 30 years. |
B.The five-year plan doesn’t work. |
C.It is hard to put out the fires currently. |
D.It is impossible to reduce carbon emissions. |
31. Which of the following can be the best title for the text?
A.Extreme weathers and fire seasons |
B.Wildfires and hurricanes hit the US |
C.Climate change tops risks for world |
D.Record-breaking wildfires in California |