”It’s beginning to look a lot like….Venus”

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”It’s beginning to look a lot like….Venus”

Post by Ted » Mon May 09, 2005 5:59 am

Earth Has Become Brighter, but No One Is Sure Why

NY TIMES
Reversing a decades-long trend toward "global dimming," Earth's surface has become brighter since 1990, scientists are reporting today.
The brightening means that more sunlight - and thus more heat - is reaching the ground. That could partly explain the record-high global temperatures reported in the late 1990's, and it could accelerate the planet's warming trend.


Less Reflection, More Light


Forum: The Environment
"We see the dimming is no longer there," said Dr. Martin Wild, a climatologist at the Swiss Federal Institute of Technology in Zurich and the lead author of one of three papers analyzing sunlight that appear in today's issue of the journal Science. "If anything, there is a brightening."
Some scientists have reported that from 1960 to 1990, the amount of sunshine reaching the ground decreased at a rate of 2 percent to 3 percent per decade.
In some places, the brightening of the 1990's has more than offset the dimming, Dr. Wild said. In other places, like Hong Kong, which lost more than a third of its sunlight, the dimming has leveled off, but skies remain darker than in the past. In a few places, like India, the dimming trend continues, he said.
The new papers also call attention to a major gap in the understanding of climate. Scientists do not exactly know what caused the dimming and the brightening, or how they affect the rest of the climate system.
Earth reflects about 30 percent of the incoming sunlight back into space. Slight changes in the reflectivity, possibly caused by changes in cloud cover and air pollution, can have as much impact on the climate as heat-trapping greenhouse gases like carbon dioxide.
Some scientists say that the dimming and the brightening might explain why for many years temperatures on Earth lagged what was predicted by many climate models and then shot upward more recently.
"I think what could have happened is the dimming between the 60's and 80's counteracted the greenhouse effect," Dr. Wild said. "When the dimming faded, the effects of the greenhouse gases became more evident. There is no masking by the dimming anymore."
But Dr. Rachel T. Pinker, a professor of meteorology at the University of Maryland who led the team that wrote one of the other papers, said the picture might not be so simple. More sunlight should increase evaporation rates, leading to more clouds, and the additional cloud cover could then increase Earth's reflectivity, limiting the warming effect.
"I think that's a complex issue," Dr. Pinker said. "There are many feedbacks involved."
The findings of Dr. Wild and his colleagues are based on data through 2001 from a network of ground-based sensors that directly measure the sunlight hitting the ground. But the sensors are not evenly distributed, with the greatest number in Europe, few in Africa and South America, and none covering the 70 percent of Earth's surface that is water.
Dr. Pinker's team analyzed satellite data from 1983 to 2001 that covered the globe. Its findings about brightening, which basically agree with Dr. Wild's, rely on computer models to estimate how much sunlight reaches the surface.
Finally, a team led by Dr. Bruce A. Wielicki of NASA's Langley Research Center in Virginia reports that measurements from the agency's Aqua satellite show a slight decrease in the amount of light reflected off Earth since 2000, which corresponds to a brightening on the surface.
The NASA findings conflict with measurements, reported last year, suggesting that Earth had resumed dimming since 2000. Those measurements looked at the illumination of the dark side of the Moon by light reflected off Earth.
Dr. Philip R. Goode, a professor of physics at the New Jersey Institute of Technology who was one of the researchers behind last year's report, said it was not clear why the findings differed so markedly. "We've been working with them to understand the origins of the differences," Dr. Goode said of the Wielicki group.
Dr. Wielicki said his data supported a report last month by a team led by Dr. James E. Hansen of the Goddard Institute for Space Studies in New York. In a paper published on Science's Web site, Dr. Hansen and his colleagues said much of the excess heat generated by global warming has been stored in the oceans. Even if no more greenhouse gases are added to the atmosphere, they said, Earth will continue to warm by 1 degree Fahrenheit over the coming decades, as the heat in the oceans is released into the air.
Dr. Wielicki said the amount of energy coming from the Sun matched the gain in heat in the oceans reported by Dr. Hansen. "It is consistent with the ocean heat storage that the oceanographers are seeing," Dr. Wielicki said, "and it is consistent with the climate models' predictions of what the heat storage should be."
Dr. Robert J. Charlson, a professor of atmospheric sciences at the University of Washington and an author of a commentary that accompanied the three papers, said, "This set of papers, taken together, calls attention for more emphasis on research in these topics."
But he added, "Unfortunately, impediments have come up." Four years' worth of data from the Earth Radiation Budget Satellite is unanalyzed, he said, because there is no money for scientists to work with it.
Another satellite, the Deep Space Climate Observatory, which was scheduled to be launched on a space shuttle, awaits in storage. Proposed budget cuts in earth science research at NASA could limit the analysis of data from other satellites, Dr. Charlson said.
http://www.nytimes.com/2005/05/06/science/06bright.html

Of course the Global Warming crowd will jump all over this, but I’m part pf the “Show me the Data from 2000 years Ago Crowd”
I did see a rather interesting NOVA that explained the “Oceanic Pump”—The warm water of the Gulf Stream flows North is then pumped back down to the Caribbean, though the melting of the Ice Shelves adds more fresh water, decrease the salinity and in doing so impedes the Gulf Stream Cycle.
Much of this has to do with the fresh water upsetting existing undersea currents of salt water.
I have to agree that the melting Ice Shelves are in theory capable of effecting the salinity levels of the Caribbean, but as for humans being solely responsible for warming trends, I’m not yet convinced.
t

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Post by Ralph » Mon May 09, 2005 6:03 am

I've noticed the same. This report preempted the publishing of my own findings.
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Post by Corlyss_D » Tue May 10, 2005 2:59 am

Interesting story, Ted. Here's TCS's take on it:


Things Look Brighter on Planet Earth

By Tim Worstall Published 05/06/2005

Another day, yet another report on global warming and climate change, this time a joint one from the Pacific Northwest National Laboratory (PNNL) and the Swiss Federal Institute of Technology, published in Science. The essential point that I take from this (and other, similar, research papers) is that the true position we're in is that we don't really quite know the truth yet, at least not all of it.

The authors are talking about albedo, that is, how much of sunlight falling on the earth gets absorbed and how much gets reflected. It's one of those points that is important to the science of understanding climate change and as this paper shows, one that we don't really know enough about yet (although this paper does get us further down the road to understanding it).

From the press release on it at the PNNL site we get this:

Ever since a report in the late 1980s uncovered a 4 to 6 percent decline of sunlight reaching the planet's surface over 30 years since 1960, atmospheric scientists have been trying out theories about why this would be and how it would relate to the greenhouse effect, the warming caused by the buildup of carbon dioxide and other gasses that trap heat in the atmosphere.

And then this:

Data analysis capabilities developed by ARM research were crucial in the study, which reveals the planet's surface has brightened by about 4 percent the past decade. The brightening trend is corroborated by other data, including satellite analyses that are the subject of another paper in this week's Science.



As I say above, the first thing I take from this is that we do not, in fact, know everything about this subject yet. The IPCC report is, quite clearly, not the last word on the subject, for if it were, no one would be able to find something to publish on the subject, right?



My second observation ties in neatly with my rather economically minded manner of looking at the world, back to that old second thing about the subject, that there are always opportunity costs (or, if you prefer, there is no such thing as a free lunch). While there is a hesitance to ascribe the effect found purely to changes in pollution it is at least considered:



The report's authors stopped short of attributing a cause to the cycle of surface dimming and brightening, but listed such suspects as changes in the number and composition of aerosols-liquid and solid particles suspended in air-and how aerosols affect the character of clouds.



As we know, the air has been getting cleaner these past two decades, we pump less dust, particulate matter, sulfur dioxide and other pollutants into the atmosphere, and while this is in itself a good thing, it is important to remember that there is nothing, absolutely nothing, that does not have side effects. A cleaner atmosphere means more sunlight reaching the ground, thus more heating of the atmosphere and thus more global warming. No, this doesn't mean that we should start pumping out more soot to reverse the process, I mean it as an example of the fact that we must always consider the fact that whatever we do, whenever, there are always going to be both good and bad effects. What matters is that we take decisions in full knowledge and acknowledgment of all of the effects, and work towards those solutions which have positive effects on balance.



A similar thing could be said, for example, about solar variability itself. If it is true that the observed warming is caused by factors outside our control, by the sun's variability itself, this doesn't actually mean that there is no problem. It means that what we do about it might change, but not that we should do nothing.



Commenting on the report, one of the authors states:



"The atmosphere is heated from the bottom up, and more solar energy at the surface means we might finally see the increases in temperature that we expected to see with global greenhouse warming,"

Which is a comment that can be taken two ways. One is that here is a solution to the rather uncomfortable problem that all of our models get the actual amount of warming wrong, which might be unkindly described as clutching at straws; the other is that the paper is a useful reminder that the science is not, contrary to perceived opinion, settled yet.

Before I get swamped by screams of outrage, by those calling me a greenhouse denialist, please, get a grip. It is quite obvious that there is a thing called the greenhouse effect, the differences between Venus, Mars and Earth are the only evidence one needs for that contention. I've said before and will no doubt have to say it again, I'm broadly of the Lomborg persuasion, that there is a general change in the climate going on, that humans are at least partially responsible for it and the important thing is to find out exactly what is going on and then work out how to deal with it. Papers like this add another level of complexity to this process, but do not obviate the need for such a process, rather they reinforce the notion that we should indeed be doing what we are, researching the problem as best we can.



I have no doubt that some will look at this paper and decide that we all died yesterday unless we smash capitalism, others will be less rational. Me? Scientists doing science, using the Ultimate Resource, the human mind, to understand more about the world around us. Something that will, in time, actually lead us to the solution(s) to the problems that face us.

But the most important and obvious lesson to take is that the IPCC report is not, as yet, the final word on the science of what is going on. There are more things for us to find as yet...for if the IPCC report were the done and dusted last word on the subject, why would Science be publishing this paper?


The author is a TCS contributing writer living in Europe. Find more of his writing here.



Copyright © 2005 Tech Central Station - www.techcentralstation.com
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Post by Ralph » Tue May 10, 2005 4:23 am

Today will be the first this year that I go to my office in shorts.
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Post by Barry » Tue May 10, 2005 8:42 am

Ralph wrote:Today will be the first this year that I go to my office in shorts.
I beat you to it by a few weeks :). We had a brief hot spell in April.
"If this is coffee, please bring me some tea; but if this is tea, please bring me some coffee." - Abraham Lincoln

"Although prepared for martyrdom, I preferred that it be postponed." - Winston Churchill

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http://www.davidstuff.com/political/wmdquotes.htm
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Ted

Post by Ted » Tue May 10, 2005 9:23 am

Today will be the first this year that I go to my office in shorts.
That’s nice Ralph, boxers or briefs?

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Post by jbuck919 » Tue May 10, 2005 10:08 am

Ted Baylis wrote:
Today will be the first this year that I go to my office in shorts.
That’s nice Ralph, boxers or briefs?
He's a lawyer, for heaven's sake. Briefs, of course.

There's nothing remarkable about it. All one has to do is hit the right keys at the right time and the instrument plays itself.
-- Johann Sebastian Bach

Ted

Post by Ted » Tue May 10, 2005 10:10 am

J
Very good one!
t

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Post by Ralph » Tue May 10, 2005 1:12 pm

Har har, hardee har har!
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"Only two things are infinite, the universe and human stupidity, and I'm not sure about the former."

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Post by Corlyss_D » Tue May 10, 2005 5:22 pm

jbuck919 wrote: He's a lawyer, for heaven's sake. Briefs, of course.
:lol: :lol: :lol: :lol: :lol:
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Post by Ralph » Tue May 10, 2005 8:35 pm

And Corlyss is amused? A traitor to our guild.
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