for local people to breathe, but could be contributing to freakish weather in
Canada and the United States, a team of scientists reported yesterday.
haze over many Chinese cities. But they drift upward over the Pacific, where
they are causing more large clouds to form higher in the atmosphere where it is
colder, says Renyi Zhang, an atmospheric scientist at Texas A&M University.
argue in a paper published yesterday in the Proceedings of the National Academy
of Sciences. More intense storms over the Pacific will change the air-flow
patterns around the globe, they say.
interview.
This raises the possibility that pollution is contributing to the kind ofbizarre weather and storms coastal cities like Vancouver have been experiencing,
including the December blow that devastated Stanley Park with hurricane-force
winds, Dr. Zhang says.
weather pattern will have on the continental United States and Canada, he says.
"You are probably going to have extreme weather, cold winters or warmwinters. I just can't say. The impact needs to be further evaluated," he
said.
going to change the weather everywhere and you are going to change the climate,
basically."
collected between 1984 and 2005, as well as climate models. He says he knows it
is controversial to suggest that winter storms may in part be man-made.
believe we have made a link to the pollution in China. People may have different
opinions."
What are aerosols? They are particles -- either solid or liquid --
suspended in the atmosphere. Some are natural, like sea salt. Others, like soot,
are man-made, produced when coal is burned. They can affect how clouds form,
what they look like and how often it rains.
are changing the nature of clouds over the Pacific Ocean, which may affect
global weather patterns. Scientists don't see anything similar in the Atlantic
Ocean, perhaps because North American industry is cleaner.
climate system. Aerosols in clouds may actually be helping to cool the planet by
reflecting more sunlight back into space. So if China and India send less soot
into the sky, it might accelerate the pace of global warming. Finding out
more. In April, NASA launched CloudSat (right) and CALIPSO, two satellites
equipped to investigate the role clouds play in climate. They will work in
conjunction with three satellites already in orbit to learn more about how
aerosols affect clouds and weather.