Has global warming research misinterpreted cloud behavior?
June 9, 2008Climate experts agree that the seriousness of manmade global warming depends greatly upon how clouds in the climate system respond to the small warming tendency from the extra carbon dioxide mankind produces.
To figure that out, climate researchers usually examine natural, year-to-year fluctuations in clouds and temperature to estimate how clouds will respond to humanity¹s production of greenhouse gases.
When researchers observe natural changes in clouds and temperature, they have traditionally assumed that the temperature change caused the clouds to change, and not the other way around. To the extent that the cloud changes actually cause temperature change, this can ultimately lead to overestimates of how sensitive Earth's climate is to our greenhouse gas emissions.
This seemingly simple mix-up between cause and effect is the basis of a new paper that will appear in the Journal of Climate. The paper's lead author, Dr. Roy W. Spencer, a principal research scientist at The University of Alabama in Huntsville, believes the work is the first step in demonstrating why climate models produce too much global warming.
Spencer and his co-author, principal research scientist William (Danny) Braswell, used a simple climate model to demonstrate that something as seemingly innocuous as daily random variations in cloud cover can cause year-to-year variation in ocean temperature that looks like -- but isn't -- "positive cloud feedback," a warmth-magnifying process that exists in all major climate models.
"Our paper is an important step toward validating a gut instinct that many meteorologists like myself have had over the years," said Spencer, "that the climate system is dominated by stabilizing processes, rather than destabilizing processes -- that is, negative feedback rather than positive feedback."
The paper doesn't disprove the theory that global warming is manmade.
Instead, it offers an alternative explanation for what we see in the climate system which has the potential for greatly reducing estimates of mankind's impact on Earth's climate.
"Since the cloud changes could conceivably be caused by known long-term modes of climate variability -- such as the Pacific Decadal Oscillation, or El Nino and La Nina -- some, or even most, of the global warming seen in the last century could simply be due to natural fluctuations in the climate system," Spencer said.
While the paper's two peer reviewers, both climate model experts, agreed that the issue is a legitimate one, Spencer knows the new paper will be controversial, with some claiming that the impact of the mix-up between cause and effect will be small.
"But we really won't know until much more work is done," Spencer said.
"Unfortunately, so far we have been unable to figure out a way to separate cause and effect when observing natural climate variability. That's why most climate experts don't like to think in terms of causality, and instead just examine how clouds and temperature vary together.
"Our work has convinced me that cause and effect really do matter. If we get the causation wrong, it can greatly impact our interpretation of what nature has been trying to tell us. Unfortunately, in the process it also makes the whole global warming problem much more difficult to figure out."
Source: University of Alabama
Nov 01, 2009 |
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Now this sounds like science. I salute the courage of those willing to speak out against the oppressive demands for conformity on AGW. Based on the flimsiest evidence and the advantage to certain groups we are about to stifle the US and global economy. It's time to step back and let cooler heads prevail.
Let me ask you something.
Has the world been baked to a crisp and risen dramatically in temperature every time a volcano has erupted?
Its not to hard to find out more information about these things on the web, try it some time.
"Exactly, and the amount of CO2 dumped into the atmospehre after a volcano eruption is in the order of a million times as much as all human activity since we began using fossil fuels,..."
Uh, no. CO2 produced by humans in a year is like 150 times all the CO2 produced by volcanoes in that year. You are a victim of a piece of viral nonsense.
falling.
http://www.aip.or...dex.html
The most importatn part of the main article is
"But we really won't know until much more work is done," Spencer said.
Which is in reference to the cause-effect relationship, ralated to the MJO, he claims to have found. Whichever way, the result for climatology is very small and cannot readjust know results from the palsoclimate record.
While you deniers can say what you want, the earth is warming as plants, animals move north and soon all the glaciers will have melted stopping the flows to many river systems which will seriously cut food production.
While I'm not fond of some of the science of GW, it is undeniably happening. While CO2 isn't as large a factor I believe we still need to tax fossil fuels, cut their use for health, national/economic security reasons.
To not tax them, especially oil to pay the costs of the Persian Gulf military and oil wars costs and giving our enemies like Iran, Russia, oil dictators and terrorist $1T in 2 yrs if we don't I think is treason. Better our gov tax it and give us tax breaks and help switching to more eff and alt energy sources than big oil, our enemies get it. Coal's costs are just as bad though from poisoning, destroying everything from land, water and air.
For instance I'd like to see a halt to jets flying above 28k' for a week or month to see what the lack of contrails does to the weather, GW.
I forgot to mention CO2 acidifying the oceans is a huge threat.