Skip to comments.Climate Effects of Atmospheric Haze a Little Less... Hazy
Posted on 09/11/2009 10:35:25 PM PDT by neverdem
Scientists have used a new approach to sharpen the understanding of one of the most uncertain of mankind's influences on climate - the effects of atmospheric "haze," the tiny airborne particles from pollution, biomass burning, and other sources.
High resolution (Credit: NOAA)
The new observations-based study led by NOAA confirms that the particles ("aerosols") have the net effect of cooling the planet - in agreement with previous understanding - but arrives at the answer in a completely new way that is more straightforward, and has narrowed the uncertainties of the estimate. The findings appear in this week's Journal of Geophysical Research - Atmospheres.
The researchers, led by NOAA scientist Daniel M. Murphy of NOAA's Earth System Research Laboratory in Boulder, Colo., applied fundamental conservation of energy principles to construct a global energy "budget" of the climate's "credits" and "debits" - heating and cooling processes - since 1950, using only observations and straightforward calculations without the more complicated algorithms of global climate models. They then calculated the cooling effect of the aerosols as the only missing term in the budget, arriving at an estimate of 1.1 watts per square meter. A watt is a unit of power.
The results support the 2007 assessment by the Intergovernmental Panel on Climate Change (IPCC) that estimated aerosol cooling at 1.2 watts per square meter. But the new study places that estimate on more solid ground and rules out the larger cooling effects that were previously thought to be possible.
"The agreement boosts our confidence in both the models and the new approach," said Murphy. "Plus, we've been able to pin down the amount of cooling by aerosols better than ever."
The narrower bounds on aerosol effects will help in predicting climate change and accounting for climate change to date.
In balancing the budget for the processes perturbing the heating and cooling of the Earth, Murphy and colleagues found that since 1950, the planet released about 20 percent of the warming influence of heat-trapping greenhouse gases to outer space as infrared energy. Volcanic emissions lingering in the stratosphere offset about 20 percent of the heating by bouncing solar radiation back to space before it reached the surface. Cooling from the lower-atmosphere aerosols produced by humans balanced 50 percent of the heating. Only the remaining 10 percent of greenhouse-gas warming actually went into heating the Earth, and almost all of it went into the ocean.
The new study tackled what the IPCC has identified as one of the most uncertain aspects of the human impacts on climate. Aerosols, which can be either solid or liquid, have complex effects on climate. Sulfate particles formed from pollution can cool the Earth directly by reflecting sunlight. Soot from biomass burning absorbs sunlight and warms the Earth. Aerosols can also affect the formation and properties of clouds, altering their influence on climate. The net effect of all these direct and indirect factors is a cooling by aerosols, which has partially offset the warming by greenhouse gases.
Authors of the study are Daniel M. Murphy, Susan Solomon, Robert W. Portmann, and Karen H. Rosenlof of NOAA's Earth System Research Laboratory; Piers M. Forster of the University Leeds, UK; and Takmeng Wong of the NASA Langley Research Center. NOAA understands and predicts changes in the Earth's environment, from the depths of the ocean to the surface of the sun, and conserves and manages our coastal and marine resources.
Look Ma, no models.
.................. The net effect of all these direct and indirect factors is a cooling by aerosols, which has partially offset the warming by greenhouse gases. ...........
“I ain’t be no scientist, but when I looks into a hazy air downwind from a belching power plant, I don’t need no hat;
Yet, when after it rains, and da sun shines, I needs ma hat ‘cause the sun be stronger an’ warmer!
I don’t know what counts as the fancy named “aerosols”
But, I’d like to repost my response to an earlier Global Warming FR thread:
I BELIEVE THAT MAN IS RESPONSIBLE FOR WARMING OF THE GLOBE!
But, not as you might think.
I hear abour sun cycles, and that is proper!
But think about recent mankinds influence on the amount of sunlight hitting the surface of the earth.
In past decades man heated homes with wood, peat, coal - all spewing their particulates into the air... Today #2 oil and natural gas are high efficiency clean fuels.
Trains and boats spewed their coal fired effluents into the air, with huge pollution. Today, these are all highly efficient diesel electric engines.
Up to the 1950s all metal working industries relyed on the coke fueled cupola to melt metal, belching millions of tons of particulates in the air. Today, these are all electric furnaces, and whatever industrial smokestacks exist, they are all fitted with scrubbers to eliminate particulates in the air.
Todays automobile spews 5% of noxious gases as compared to 1970s lead gassed autos before the catalytic converter.
Yes, I believe that mankind has caused the planet to warm in the past fifty years.
Not because of harmless carbon dioxide, but because of our highly successful efforts to clean up the atmosphere, which now allows so much more of the suns energy to warm the surface of the earth.
(Ive never seen a scientist espouse my theory of air cleanliness creating more solar warmth, but I truly believe that industrial mankinds efforts to clean our atmosphere are resulting in the warming or our planet.)
??So, what are these scientific “aerosols”??
Does letting more sunlight get through the atmosphere cause more sunburn, and more ground warming???
Thanks for posting.
examiner.com cannot be posted to FR. Copyright complaint.
That's too bad. Why not require excerpts?
Funny how this same time period coincides with the global movement to regulate and control such aerosols; so warming is still our fault -- even if we leave CO2 completely out of the equation.
Many studies show that over the past 50 years or so, less sunlight has been getting to earth - see global dimming. Aerosols, soot and dust have been blamed, particularly that injected into the upper atmosphere by commercial jet travel.
.................Many studies show that over the past 50 years or so, less sunlight has been getting to earth - see global dimming. Aerosols, soot and dust have been blamed, particularly that injected into the upper atmosphere by commercial jet travel..........................
You can’t convince me that a few thousand jets, with 85% fuel efficiency, does more atmospheric harm more than counteracting 500 million automobiles that spew 95% less effluents than 30 years ago.
What about all the industrialized world power plants and smokestacks, now all equipped with scrubber systems; what about all the world’s metalworking industries converting from coke spewing cupola stacks to electric furnaces.
Or, are you trying to tell us that “global dimming” is in the process of replacing “global warming” as the new science of fantasy?
“Algore, please pick up the red courtesy phone!”