dalem

I conflated two points - my comment about modeling was intended to speak to your question about the general worth of models, not Hansen's data specifically.

See my reply above. I'd really need access to the raw numbers and my education of almost 20 years ago to do a statistical teardown of such a curve. I "see" a slight upwarding from the 1970s, you don't - it's certainly a shallow one, I'll give you that, but it's there.

But again, the important things to remember, for you and for me, are

1) There is really no good, solid data for solar output much earlier than 1950. It's really speculative and correlative before that (sunspots, growth rings, etc.) so in my opinion that part of the chart shouldn't even exist because it implies similar data throughout.

2) There is no proof that there is, or should be, a simple, linear relation between solar output and global temperature. I happen to think that it's the first and best candidate and should be studied extensively so we can determine its relevance, certainly before we start crying about CO2 and the like.

-dale

ArmchairGeneral

All righty. Sounds reasonable.

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Debbie

From Discovery--------

Shifting Layers Over Arctic Blamed for Ice Melt
Marlowe Hood, AFP

Jan. 2, 2008 -- The dramatic loss of the Arctic ice cap may have been triggered by disruption to the thermal layers of atmosphere stacked over Earth's far north, according to Swedish research to be published Thursday.

The study, published in Nature, offers a new explanation for the rise in the Arctic's surface temperature, which over the past century has been nearly two degrees Celsius (3.6 Fahrenheit), or twice the global average.

Until now, the big suspect in "Arctic amplification" has been reflectivity of sunlight.

When the Sun's rays hit snow or ice, most of that solar energy bounces back into space -- but as those melting surfaces give way to dark-blue sea, the heat is absorbed instead.

This self-reinforcing process, called a feedback, is an established factor in accelerating warming in snow and ice.

But Stockholm University scientists led by Rune Graversen believe a possibly bigger cause for Arctic warming could be changes in heat transport in the middle of the troposphere, an atmospheric band that extends 10 kilometers (seven miles) above Earth's surface.

In polar regions, the layers of relative heat above the surface are usually stable. But Graversen says that over the last two decades or so there have been changes in Arctic atmospheric circulation which have brought in heat and moisture.

The moisture is particularly important, as it helps form persistent low cloud over the Arctic.

Moisture-laden clouds at this altitude tend to absorb heat from the Sun, thus bringing a warming effect close to the surface. In contrast, high-altitude clouds, which mainly comprise icy crystals, reflect heat back into space, and thus cool the surface.

The circulatory shifts have an especially big impact in summer, says Graversen.

In 2007, summer sea ice in the Arctic shrank to about four million square kilometers (2.4 million square miles), a 23 percent decrease from the previous record low of 5.3 million square kilometers in 2005.

A second study, also in Nature, meanwhile, shows that the capacity of vegetation to absorb carbon dioxide (CO2) appears to be ebbing, with potentially serious consequences for global warming.

Currently, about 50 percent of all the CO2 produced by burning fossil fuels is soaked up -- "sequestered" -- by land masses, mainly through forests, and by oceans.

Remarkably, that percentage has remained stable even as the output of man-made greenhouse gases has increased.

Up to now scientists have assumed that longer growing seasons were a silver lining of climate change because the warmer temperatures gave photosynthesising plants more time to remove the most important of these gases -- CO2 -- from the atmosphere.

This view has been bolstered by satellite images showing a clearly visible "greening trend," notably in the northern hemisphere.

But Shilong Piao of France's National Center for Scientific Research (CNRS), found that over the past 20 years the planet's biomass above the 20th parallel released nearly as much CO2 in the fall or autumn as it soaked up during the spring.

"If future autumn warming occurs at a faster rate than in spring, the ability of norther ecosystems to sequester carbon may be diminished earlier than previously suggested," he warns.

While Piao's study draws a clear link between rising temperatures and reduced carbon uptake, projecting future trends is very difficult, cautions John Miller, a expert on carbon cycles at the University of Colorado, in a commentary, also published in Nature.

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JAD_333

Debbie, I'll call you and raise another one...

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reasonmclucus

The relation between changes in solar radiation and global temperature is non-linear. Water heats and cools slower than land masses. Thus Sea Surface Temperatures will not increase as quickly as solar output increases and will not begin heating the atmosphere or transporting heat from the equator to polar regions until some time after the solar output increase. Similarly, when solar output declines SSTs will remain elevated for some time afterward.

As solar output increases the ground covered by snow will decline allowing the sun to warm the ground that had previously been snow covered which in turn will create higher air temperatures which will melt more snow. When solar output declines the ground covered by snow will increase resulting in more reflection of light back into space and less heating of the air by the ground.

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Steve Culpepper

Global Warming or Not, one thing I do know in a very certain manner. All the purveyors of so called "Carbon Credits" and all the Tree Hugging Initiatives in the World will not stop and turn around on a dime the very basis of the World Economy --- OIL. Ain't gonna happen.

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SCUL