Aerosols cool more than expected - Researchers measure smog's effect on global warming.

news@nature.com ^ | 21 December 2005 | Quirin Schiermeier

[neverdem]

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Published online: 21 December 2005; | doi:10.1038/news0051219-11

Aerosols cool more than expected

Researchers measure smog's effect on counteracting global warming.

Quirin Schiermeier

Hot times: cities would be even warmer if not covered by a blanket of smog. © Punchstock

Cleaning the air could accelerate global warming, according to a new study.

The particles in the soot and haze from industrial and domestic fires, called aerosols, cause respiratory diseases and other health problems for people in polluted areas, including many Asian cities.

But aerosols also dim the sky over land and sea, and so cool the planet. By scattering and absorbing sunlight - how much depends on the particles' size and optical properties - they prevent the Earth from heating up more than it already has owing to the greenhouse effect.

The balance between the two effects has been a wildcard in climate predictions. In its last report, published in 2001, the Intergovernmental Panel on Climate Change (IPCC) could put only a broad range of possible values on aerosol cooling.

Now researchers at the UK Met Office in Exeter and the Geophysical Fluid Dynamics Laboratory in Princeton, New Jersey, have provided the first calculation based on observations, rather than models.

The team concludes that the cooling effect of aerosols is probably at the high end of IPCC estimates. So cleaning the air will lead to substantial warming. Without aerosols for example, since 1900 the planet might have warmed at least an additional 0.3 °C above the 0.7 °C rise that actually happened.

Dark skies

The team, led by Met Office researcher Nicolas Bellouin, calculated the amount of aerosols in the air using data from NASA's Terra and Aqua satellites and observations made from aircraft. The researchers then calculated how much light that material would absorb. They publish the results in Nature this week¹.

The result is the most comprehensive measurement of soot so far. "This is a very timely addition to modellers' work," says Meinrat Andreae, an atmospheric scientist at the Max Planck Institute of Chemistry in Mainz, Germany.

Recent models have pointed to a huge range of effects from aerosols, he says. Observations will help sort out the confusion.

In a recent model of his own, Andreae concluded that without aerosol cooling, global temperatures could rise between 6 and 10 °C by 2100 - well beyond current IPCC predictions². Aerosols partly disguise the sensitivity of our climate to rising levels of greenhouse gases, he says.

Heating up

Soot and haze could be even more cooling than Bellouin's team calculates, says Andreae. Aerosols affect other climate properties, such as cloud formation, the effects of which have yet to be measured.

Industrial aerosol emissions have dropped in the United States and Europe since 1990. Worldwide, however, Asia's economic growth is feeding a modest upward trend in their output. But Asian emissions are growing less sharply than was expected, thanks to policies such as a switch to clean energy in the industrial areas around Beijing and Shanghai.

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References

1. Bellouin N.,

   Boucher O.,

   Haywood J.&

   Reddy M. S. . Nature, 438. 1138 - 1141 (2005). | Article |

2. Andraea M.. O.,

   Jones C. D.,

   Cox P. M., . Nature, 435. 1187 - 1190 (2005). | Article |

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[neverdem]

This story got plenty of coverage, not. I came across this Bloomberg story buried in the NY Times' Science section. IIRC, Bloomberg stories can't be posted, just linked. Pollution May Slow Warming; Cleaner Air May Speed It, Study Says

[MNJohnnie]

Unbelievable. Guess they are going to cling to this lie as long as humanly possible. We KNOW sunspots cycles have effected global weather historically but there is NO political propaganda to be made for High Priests of Narcissists in the Church of Environmental Extremism so they cling to a failed dogma of Man Made Global Warming Infallibility! This goes beyond stuck on stupid.

[sgtbono2002]

So now we are going to stop Global warming with Smog.

LMAO These guys come up with new crap every day.

[Fzob]

Cleaning the air could accelerate global warming, according to a new study.

Cool, can I go back to burning leaves in the fall in a old 55 gal drum. I used to love the smell.

[moog]

I just knew that factory was responsible for that snowstorm. BUT did ANYONE listen to me?? NO!!!!!

The Abominable Snowman told me himself.

[blackie]

Another myth exposed. *sigh*

[RegulatorCountry]

Will I get a Kyoto credit for burning trash in the fireplace? I need a new SUV to help save the planet.

[moog]

55 gal drum.

Got an old bass one you can use if you want.

[Eastbound]

Aerosols. Aerosols. Hmmmmmm! Where have I heard that word before? Has a familiar ring to it.

[Slings and Arrows]

So now we're back to Global Cooling as the Eco-Bogeyman Of The Day? That's just so...70's.

[RegulatorCountry]

"So now we're back to Global Cooling as the Eco-Bogeyman Of The Day? That's just so...70's."

And world socialism is still the answer. Anybody surprised?

[EGPWS]

Aerosols cool more than expected - Researchers measure smog's effect on global warming.

Let God sort it out and allow us to do what is best for us locally.

Or do we consider humanity as powerful as the creator in determining our demise or Utopia in terms of his creation, which ever comes first?

[Kimmers]

Soooo does this mean the ladies with big hair should keep their cans of Aqua-Net?

[Gabz]

I was wondering if someone would mention that tidbit :)

[VOA]

bump

[Hugin]

"could accelerate...a wildcard...could put only a broad range...the first calculation based on observations, rather than models...is probably at the high end...might have warmed at least an additional 0.3 °C...global temperatures could rise between 6 and 10 °C...could be even more cooling..."


In other words, they are still guessing.

[Always Right]

My idea to fix global warming is to legalize CFC's again to open up that massive Ozone hole. This will let those evil CO2 gases to escape from the earth's atmosphere and save the planet.

[Nathan Zachary]

"So now we are going to stop Global warming with Smog. LMAO These guys come up with new crap every day.

China is a leading the world in global warming prevention, LoL! Any bet's on that headline popping up soon?

Volcanic activity has always acted as a 'global cooler' throughout the ages, as well as a global heater. Puny mankind has no effect on the climate at all. Geothermal activity periodically warms the oceans, which in turn warms the atmosphere. Global warming and cooling has been going on since the beginning of time as a result of this, as well as cosmic influences.

These lunatic "scientists" just can't seem to figure this out. To think mankind can control the climate is absurd, but it is a good way to shake money out of the pockets of gullible populations.

[Nathan Zachary]

"Will I get a Kyoto credit for burning trash in the fireplace? I need a new SUV to help save the planet."

I burn six cords every winter. That aught to be worth millions in credits! I could sell them to the Canadians. :o)

[4mycountry]

Without aerosols for example, since 1900 the planet might have warmed at least an additional 0.3 °C above the 0.7 °C rise that actually happened.

Whoop-de-twang. Geez...