久久亚洲国产成人影院-久久亚洲国产的中文-久久亚洲国产高清-久久亚洲国产精品-亚洲图片偷拍自拍-亚洲图色视频

  Home>News Center>World
         
 

'Pollutants keeping global warming at bay'
(China Daily/The Guardian)
Updated: 2005-12-23 06:15

Cutting air pollution could trigger a greater surge in global warming than previously thought, suggesting future rises in sea level and other environmental consequences have been underestimated, climate scientists reported yesterday.

The warning comes after researchers investigated the effect of fine particles known as aerosols on climate change. Aerosols particles smaller than one-hundredth of a millimetre are churned out from factory chimneys, from the burning of fossil fuels and forest fires, although sea salt and dust particles swept up by desert storms add to levels detected in the atmosphere.

Because the particles are so light, they remain aloft for long periods, where they cool the Earth by reflecting radiation from the sun back out to space. Higher levels of aerosols lead to the formation of brighter clouds made up of smaller water droplets, which reflect still more of the sun's warming radiation.

Cutting down on aerosols by improving air quality means that the Earth will in future be less shielded against the sun's rays.

Writing in the journal Nature, scientists at the Meteorological Office and the US Government's National Oceanic and Atmospheric Administration report that climate models used to predict future global warming have badly underestimated the cooling effect of aerosols.

"We found that aerosols actually have twice the cooling effect we thought," said Nicolas Bellouin, a climate modeller at the Met Office. The consequence is that as air quality improves and aerosol levels drop, future warming may be greater than we currently think."

Bellouin's study suggests that even by conservative estimates, climate models have got the impact of aerosols on the climate wildly wrong. "The discrepancy between the models and our observations is not good news," he said.

The scientists used images from a US satellite called Modis to look at how much sunlight aerosols in the atmosphere reflect back to space on cloud-free days. Using another satellite called Toms, they were able to separate readings for the effect of smaller aerosols produced by natural processes from those produced by human activity.

Scientists had assumed that the amount of sunlight reflected by aerosols from industry and fuel burning was tiny compared to the extra reflective cloud cover they caused, but Bellouin's research suggests the processes are equally important. Bellouin says climate scientists will have to plug the new information into their models before they can be sure of the implications for global warming.

One possibility is that while the latest study shows scientists have underestimated the so-called direct effect of aerosols reflecting the sun's rays, they may have overestimated the indirect effect they have on cloud cover, meaning the overall error of climate models would not be serious.

Earlier this year, Peter Cox at the Centre for Ecology and Hydrology in Winfrith, Dorset, warned that if the cooling effect of aerosols turned out to be greater, it could trigger faster global warming.

"It's quite a bizarre thing, because the last thing you want to suggest to people is that it would be a good idea to have dirty air, but as far as climate change is concerned, that's right. Everyone would be getting asthma, but the environment would be cooler.

"That said, the direct effects of air quality, particularly in urban areas, are so important to human health, that it would be crazy to think of anything other than health damage," he said.

The Guardian

(China Daily 12/23/2005 page1)



Rebels kill 8 policemen in ambush in Peru
Public transport strike in New York
Torrential monsoon rains in southern thailand
 
  Today's Top News     Top World News
 

Japan FM's 'China threat' remarks criticized

 

   
 

Reforms of SOEs will push ahead next year

 

   
 

China to embark on road of peaceful rise

 

   
 

Optimism increases in epidemic battle

 

   
 

China and OPEC start energy dialogue

 

   
 

China becomes a net auto exporter

 

   
  New York's 3-day transit strike ends
   
  Saddam's claims of abuse denied in court
   
  Japan rejects alternative to criticized war shrine
   
  White House is lying, Saddam tells court
   
  Union heads could face jail over New York strike
   
  Saddam claims he was 'beaten by Americans'
   
 
  Go to Another Section  
 
 
  Story Tools  
   
  News Talk  
  Are the Republicans exploiting the memory of 9/11?  
Manufacturers, Exporters, Wholesalers - Global trade starts here.
Advertisement
         
主站蜘蛛池模板: 狠狠色丁香婷婷综合 | 伊人久久综合热青草 | 国产精品一区伦免视频播放 | 日韩免费一级毛片欧美一级日韩片 | 亚洲国产精选 | 国产一区二区三区精品视频 | 欧美黄视频在线观看 | 国产亚洲欧洲一区二区三区 | 亚洲精品成人久久久影院 | 不卡无毒免费毛片视频观看 | 国产成人亚洲精品91专区高清 | 亚洲波多野结衣日韩在线 | 在线观看日本免费视频大片一区 | 美女福利视频午夜在线 | 日本69xxxxxxxxx69| 精品在线小视频 | 黄色网址视频在线观看 | 国产精品亚洲综合网站 | 成人午夜在线视频 | 毛片免费在线观看 | 精品国产一区二区三区久久影院 | 国产三级小视频在线观看 | 我想看三级特黄 | 99久久精品国产自免费 | 精品久久久久国产免费 | 自拍偷自拍亚洲精品10p | 日本一级毛片片在线播放 | 欧美日韩一区二区不卡三区 | 一本综合久久国产二区 | 久久九九视频 | 日本一区二区三区不卡在线视频 | 欧美亚洲国产激情一区二区 | 特级a毛片| 毛片看看| 中文国产日韩欧美视频 | 国产精品18久久久久久小说 | 欧美一级人与动毛片免费播放 | 中文精品久久久久国产不卡 | 特级一级毛片视频免费观看 | 国产成人久久精品区一区二区 | 精品色综合 |