Beam me to Planet Gore !
Posted on 04/17/2008 6:21:08 PM PDT by Aristotelian
· Meltwater plays only small role in glacier flow · Study casts doubt on 'lubrication' theory
Fears that the rapid draining of water from the top of Greenland's ice sheet may be contributing to the rise of global sea levels have been allayed by new research. Though scientists confirmed that the water can drain away faster than Niagara Falls, it did not seem to accelerate the movement of the ice sheet into the ocean as previously thought.
Receding ice sheets are of major concern to climate scientists because the melting water could lead to a rise in sea levels. In addition, the melting can encourage feedback mechanisms that amplify the warming effects of greenhouse gases in the atmosphere: ice and snow reflect sunlight, so less of them means more heat is absorbed by the Earth. Observations have already shown that the speed at which glaciers at the edge of Greenland are moving into the sea has doubled in the past two decades.
Thousands of lakes form on top of Greenland's glaciers every summer due to the increased sunlight and warmer air. Satellite observations have shown that these lakes often disappear, often in as little as a day, but no one knew where the water was going or how quickly it moved.
(Excerpt) Read more at guardian.co.uk ...
Another nail in the global warming coffin.
The ice sheets have been steadily retreating since the end of the last Ice Age, around 12,500 years ago. Sea level rose more than 100 meters since then.
Florida was three times bigger, the Gulf of Mexico was inhabited, and what’s now Long Island Sound was a valley with a river going through it and people probably living there. Some native American tribe is thinking about doing archeology in the Sound.
We must learn to adapt to Earth’s changes if we are to survive over the short term, 80,000 years or so.
Buying Gorebulbs and solar panels will not stop the oscillation of the ice sheets, look up Milankovitch Theory.
It’s the Guardian. Nothing to read here folks, move along, move along. Even the New Scientist (which was once a solid light read for science) has become a joke. Virtually everything from psychology to food relates to “warming”. Thankfully, the ill-educated have not invaded the physics sections yet, and it’s possible they never will - since those sections actually have some real science.
Note that it has taken 18,000 years to melt 60% of the ice from the last ice age. The remaining ice is almost entirely at the north and south poles and is isolated from warmer weather. To melt the ice of Greenland and Antarctica would take thousands of years under any realistic change in climate. In the case of the East Antarctic Ice Sheet, which accounts for 80% of the Earth’s current ice, Sudgen argues that it existed for 14,000,000 years, through wide ranges in global climate. The IPCC 2001 report states “Thresholds for disintegration of the East Antarctic ice sheet by surface melting involve warmings above 20° C... In that case, the ice sheet would decay over a period of at least 10,000 years.” [31] The IPCC is the United Nations’ scientific committee on climate change; its members tend to be the minority that predicts global warming and its statements tend to be exaggerated by administrators before release. Given that the IPCC tends to exaggerate the potential for sea level rise, it is clear that no scientists on either side of the scientific debate on global warming fear the melting of the bulk of Antarctica’s ice.
See. “What If All the Ice Melts?” Myths and Realities by Wm. Robert Johnston
last updated 29 December 2005
http://www.johnstonsarchive.net/environment/waterworld.html
Thank you very much for that!
Okay...
Although variations of the Milankovitch theory can account for some aspects of climate change, there are serious failures that require attention. In particular, we will discuss the status of the "causality problem", the apparent fact that major shifts in climate occur prior to the Milankovitch driving force [Gondring: a fatal flaw, according to climate-change dissenters who point to the 800-year-lag in COfont size=-1>2 behind temp, without considering the fact that we could be reversing the forcing], and the spectral peak problem, in which the spectral shapes predicted by the Milankovitch theory do not match those in the spectrum and the bispectrum of the data. The standard Milankovitch theory ascribes all climate change to the same mechanism: summer insolation in the northern hemisphere. Variations in cloud cover are ignored, even though the net forcing of clouds is (at the present time) approximately 30 Watts per square meter -- substantially greater than the rms variations in insolation (18 Watts per square meter). Thus changes in cloud cover could be more important than changes in the standard Milankovitch parameters. We will discuss mechanisms that link variations in the orbital inclination of the Earth to changes in cloud cover, and how these address the causality problem, the spectral problems, and several other failures of the Milakovitch theory. How can we reconcile the failures of the Milankovitch approach with its obvious successes (e.g. in accounting for the 23 kyr cycle in sapropels, and the atmospheric oxygen variations in the Vostok data)? The answer is that climate is multi-dimensional. Insolation certainly affects climate. But we should not make the logical mistake of therefore assuming it accounts for the 100 kyr cycle of glaciation that has dominated for the past 800 kyr.
Orbital changes occur over thousands of years, and the climate system may also take thousands of years to respond to orbital forcing. Theory suggests that the primary driver of ice ages is the total summer radiation received in northern latitude zones where major ice sheets have formed in the past, near 65 degrees north. Past ice ages correlate well to 65N summer insolation (Imbrie 1982). Astronomical calculations show that 65N summer insolation should increase gradually over the next 25,000 years, and that no 65N summer insolation declines sufficient to cause an ice age are expected in the next 50,000 - 100,000 years ( Hollan 2000, Berger 2002).
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Your clip focuses on the 100 KY signal. It correlates better to the 40KY cycle.
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Milutin Milankovitch
Using these three orbital variations, Milankovitch was able to formulate a comprehensive mathematical model that calculated latitudinal differences in insolation and the corresponding surface temperature for 600,000 years prior to the year 1800. He then attempted to correlate these changes with the growth and retreat of the Ice Ages.
To do this, Milankovitch assumed that radiation changes in some latitudes and seasons are more important to ice sheet growth and decay than those in others. Then, at the suggestion of German Climatologist Vladimir Koppen, he chose summer insolation at 65 degrees North as the most important latitude and season to model, reasoning that great ice sheets grew near this latitude and that cooler summers might reduce summer snowmelt, leading to a positive annual snow budget and ice sheet growth.
But, for about 50 years, Milankovitch's theory was largely ignored. Then, in 1976, a study published in the journal Science examined deep-sea sediment cores and found that Milankovitch's theory did in fact correspond to periods of climate change (Hays et al. 1976). Specifically, the authors were able to extract the record of temperature change going back 450,000 years and found that major variations in climate were closely associated with changes in the geometry (eccentricity, obliquity, and precession) of Earth's orbit. Indeed, ice ages had occurred when the Earth was going through different stages of orbital variation.
Since this study, the National Research Council of the U.S. National Academy of Sciences has embraced the Milankovitch Cycle model.
...orbital variations remain the most thoroughly examined mechanism of climatic change on time scales of tens of thousands of years and are by far the clearest case of a direct effect of changing insolation on the lower atmosphere of Earth (National Research Council, 1982).
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As with any theory being actively discussed (no consensus!) we can pick pro-and-con papers. I think that Milankovitch is not perfect, but does explain a lot, while typical AGW theories cannot predict past climate changes at all. The issue is complex, when you look at the record over several million years the climate oscillates whenever the poles ice up. Multiparameter oscillators are hard to model. There have been some recent papers with models supporting AGW, but if you read the paper you can see that the researcher is using the 2006 UN climate history data, which does not go back far and minimizes the Medieval Warm Period and Maunder Minimum. In particular there was a paper that dimissed solar influences, but did not include data from the Maunder Minimum since they used the UN data.
Look at his pdf of additional data as well.
Of course they correlate well. That’s not disputed, is it?
Indeed so .... at least for sentient individuals who are paying attention, but it is unlikely that facts will ever shake the faith of the committed loony left.
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