B
Global warming will significantly increase the frequency of lightning strikes, according to a US research.
The research, published in Science, was carried out with the help of data from a US network of lightning detectors. The teams says they have calculated how much each extra degree in temperature will raise the frequency of lightning. "For every two lightning strikes in 2000, there will be three lightning strikes in 2100," said David Romps, at the University of California, Berkeley.
As well as triggering more wild fires, he said, this would alter the chemistry of the atmosphere.
The team's work reveals a new method of working out the relationship between temperature and lightning storms, by estimating the heat energy available to "fuel" storm clouds. "As the planet warms, there will be more of this fuel around, so when thunderstorms get triggered, they will be more energetic," said Prof Romps.
He and his colleagues calculated that every 1℃rise in global temperature would lead to an increase in the frequency of lightning strikes by 12%.
They validated their calculations against a year of data from the US National Lightning Detector Network, which detects an electromagnetic pulse every time lightning strikes in the US. "The resulting data is exquisite," said Dr Romps. "The position and time of every lightning strike is very accurately recorded."
As well as triggering half of the wildfires in the US, each lightning strike— a powerful electrical discharge— sparks a chemical reaction that produces a "puff" of greenhouse gases called nitrogen oxides." Lightning is the
dominant source of nitrogen oxides in the middle and upper troposphere（对流层）," said Prof Romps.
And by controlling this gas, it indirectly regulates other greenhouse gases including ozone and methane. Prof Romps said that this was an example of a large response to "what sounds like only a few degrees of warming".
A scientist at the UK Met Office said it was important to understand future lightning patterns, but cautioned that there were still uncertainties in the researchers' model that needed to be tested further. The Met Office added that the application of this forecast to other parts of the world could be limited by the fact that rainfall patterns were very uncertain in many regions.
The best title for the passage should be          .

A．Global warming causes more wildfires

B．A new research on the effects of global warming

C．Climate change will make lightning strike more

D．The relationship between temperature and lightning

According to Prof. Romps,          .

A．it remains to be seen whether the lightning will trigger wildfires

B．the research is working out the causes of the wildfires

C．they detected an electromagnetic pulse every time lightning strikes in the US

D．lightning plays a major role in creating nitrogen oxides in the middle and upper troposphere

What did the UK Met Office think of the result of the research?

A．The researchers’ model was not convincing enough.

B．The rainfall patterns stayed stable in many areas over a long time.

C．The result wouldn’t be applied to other parts of the world.

D．No research would be needed to make sure of the result.