共用题干
Global Warming

1 Smoke is clouding our view of global warming,protecting the planet from perhaps
three-quarters of the greenhouse（温室）effect.That might sound like good news, but
experts say that as the cover diminishes in coming decades,we are facing a dramatic
increase of warming that could be two or even three times as great as official best
guesses.
2 This was the dramatic conclusion reached last week at a workshop in Dahlem,Berlin,
where top atmospheric scientists got together,including Nobel prize winner Paul Crutzen
and Swedish scientist Bert Bolin,former chairman of the UN's Intergovernmental Panel on
Climate Change(IPCC).
3 IPCC scientists have suspected for a decade that aerosols（浮质）of smoke and other
particles from burning rainforest,crop waste and fossil fuels are blocking sunlight and
counteracting the warming effect of carbon dioxide（二氧化物）emissions.Until now,they
reckoned that aerosols reduced greenhouse warming by perhaps a quarter,cutting
increases by 0.2℃．So the 0.6℃of warming over the past century would have been 0.8℃
without aerosols.
4 But the Berlin workshop concluded that the real figure is even higher一aerosols may have
reduced global warming by as much as three-quarters,cutting increases by 1.8℃.If so,
the good news is that aerosols have prevented the world getting almost two degrees warmer
than it is now.But the bad news is that the climate system is much more sensitive to
greenhouse gases than previously guessed.
5 As those gases are expected to continue accumulating in the atmosphere while aerosols
stabilize or fall,that means"dramatic consequences for estimates of future climate
change",the scientists agreed in a draft report from the workshop.

The increase of greenhouse gases_________.
A:will influence future climate change
B:was somewhat surprising
C:will rise rapidly
D:was known to us all
E:was much higher than had been expected
F:will drop dramatically