Greenland's ice sheet: Climate change outlook gets a little more dire

[Vergent]

http://www.csmonitor.com/Environment/2012/0313/Greenland-s-ice-sheet-Climate-change-outlook-gets-a-little-more-dire

[PhillipS]

http://www.csmonitor...ittle-more-dire

Thank you for that link - it was an interesting article. I didn't feel it was new information but rahter corroboration of earlier studies and projections.

The statement in the article I found most sobering was:

During much of the past decade, the ice sheet lost mass at a rate of between 191 billion and 240 billion tons a year, according to another study, based on ICESat satellite data.

That's about 30 tons of Greenland meltwater annually for every man, woman and child on this planet. Water is heavy, of course, so that works out to only around 7,500 gallons per person - but that's still a lot of melting.

One frequent comment heard from skeptics and pseudo-skeptics is that it will take thousands of years to melt the Greenland and Antarctic ice sheets. True enough if the melting is uniform and ofthe same order of magnitude as today's melting. But what they ignore is the solid evidence of past cataclysmic ice sheet breakups.

The Washington Scablands were formed when part of the Cordilleran Ice Sheet disintegrated and released the waters of Lake Missoula in massive deluges. Similar ice sheet breakups drained Lake Agassiz and Lake Ojibway. Ice, near its melting point, has little structural integritiy. Anyone who has clear icy sidewalks and driveways knows it's a lot easier at 30 F than at 0 F. As Greenland warms more of the ice at the margins of the ice sheet becomes vulnerable to flow (deformation) and collapse. Evidence for this is seen in the acceleration in the glaciers' movement.

[salbers]

Recall that the GRACE data suggests an increase in the rate of Greenland Ice Sheet melting during the past decade or so.

http://ess.uci.edu/researchgrp/velicogna/files/rignot_etal_grl2011.pdf

[Jonger]

The ice sheet could lose 20 percent of its mass over the next 500 years from temperature increases associated with so-called business-as-usual greenhouse-gas emissions through century's end. In this case, the study indicates, the ice sheet could vanish in 2,000 years.

Well that's probably worse case scenario, since hydrocarbon fuel supply will basically be history in 50 years. There will be tar sands and other reserves left, but those will be so expensive that a switch to renewable or extreme reduction will have to take place.

[PhillipS]

The ice sheet could lose 20 percent of its mass over the next 500 years from temperature increases associated with so-called business-as-usual greenhouse-gas emissions through century's end. In this case, the study indicates, the ice sheet could vanish in 2,000 years.

Well that's probably worse case scenario, since hydrocarbon fuel supply will basically be history in 50 years. There will be tar sands and other reserves left, but those will be so expensive that a switch to renewable or extreme reduction will have to take place.

Unless you know of some peer-reviewed studies I'm not familiar with - a lot of people share your opinion but it all amounts to wishful thinking. True, the world's supply of high grade fossil fuels (such as anthracite coal and 'sweet' crude oil) will run out but there are still massive quantities of lower grade fossils fuels suchas lignite and high-sulfure coal, and the tar sands you mentioned, Here's a study on projected fossil fuel use that was done in 2002 (so it's somewhat dated) which concludes petroleum use for another 98 years, natural gas for another 166 years, and coal for another 230 years.

A more recent study is the 2007 Survey of Energy Resources. From the Executive Summary document:

Moreover, at this point in time the depletion argument can only be applied to ‘conventional’ oil production: supplies from other sources (such as natural bitumen, extra-heavy oil, oil shale, derivatives of coal and natural gas), will increasingly come into play, meeting at least part of the potential deficit in liquid fuels availability. Oil will not finally run out for very many years, if ever.

Both government and industry are subsidizing billions of dollars of research and development for technologies to extract every possible tone of fossil fuels. And in exploration to locate remaining fossil fuel resources. The recent surge in fracking to access deep natural gas fields is an example of this technology development and exploration effort. But the BP Deep Horizon disaster showed the risks associated with efforts to exploit previously unrecoverable fossil fuel resources.

The bottom line is there are ample fossil fuel reserves to reach 600 ppm CO2 if they are exploited. That CO2 level would commit the Earth to several degrees of warming higher than today's temperatures. That warming would, in turn, increase the rate of ice sheet melting (and sea level rise) and would increase the release of CO2 and CH4 from thawing permafrost and hydrate deposits - further adding to the atmospheric GHG levels and forcing additional warming.

[WeatherRusty]

The ice sheet could lose 20 percent of its mass over the next 500 years from temperature increases associated with so-called business-as-usual greenhouse-gas emissions through century's end. In this case, the study indicates, the ice sheet could vanish in 2,000 years.

Well that's probably worse case scenario, since hydrocarbon fuel supply will basically be history in 50 years. There will be tar sands and other reserves left, but those will be so expensive that a switch to renewable or extreme reduction will have to take place.

Current fossil fuel usage is currently pushing CO2 concentration up at a rate of about 2ppm per year. That rate will surely only increase under BAU given the industrialization of the developing world. It is quite likely CO2 will have doubled it's pre-industrial concentration of 280ppm in 50 years or so to reach 560ppm.

All the numbers usually mentioned, from the lower range of climate sensitivity to the most dire, are based on a doubling of CO2. If we burn enough stuff to bring about a doubling of CO2, and we will the way it looks now, the science had better be grossly in error or the next several century's inhabitants are in for a very difficult time.

[cooling climate]

Current fossil fuel usage is currently pushing CO2 concentration up at a rate of about 2ppm per year. That rate will surely only increase under BAU given the industrialization of the developing world. It is quite likely CO2 will have doubled it's pre-industrial concentration of 280ppm in 50 years or so to reach 560ppm.

All the numbers usually mentioned, from the lower range of climate sensitivity to the most dire, are based on a doubling of CO2. If we burn enough stuff to bring about a doubling of CO2, and we will the way it looks now, the science had better be grossly in error or the next several century's inhabitants are in for a very difficult time.

Dear oh dear " the science had better be grossly in error ". What science or do you mean AGW tilted prediction models, what a load of horses--t.

All of these climate threads are full of the same horses--t.LOL.

[PhillipS]

Dear oh dear " the science had better be grossly in error ". What science or do you mean AGW tilted prediction models, what a load of horses--t.

All of these climate threads are full of the same horses--t.LOL.

Your unsupported opinion is noted. And you might as well spend your time LOLing since you don't appear to be spending any time studying the actual science involved. Let me guess - reality makes your head hurt.

I'm curious - did you really think that your post would help the pseudo-skeptical position in any way? That those of us who have spend years reading peer-reviewed climate research to deepen our understanding of what we are seeing around the world would read your post and say "Omigod, he's right! Thanks to CC the veil has lifted!"? Just askin'.

[WeatherRusty]

Dear oh dear " the science had better be grossly in error ". What science or do you mean AGW tilted prediction models, what a load of horses--t.

All of these climate threads are full of the same horses--t.LOL.

A doubling of CO2 produces a radiative forcing of 3.7W/m^2 as determined by the physics of radiative transfer theory. The HITRAN Database of infrared atmospheric propagation commissioned by the U.S. Air Force provides for this determination. It is good enough for military infrared equipment and weaponry such as heat seeking missiles. The physics which informs us that a forcing of 3.7W/m^2 will induce a gray body warming of slightly less than 1.2C of Planck Response is rock solid science. No computer modeling required.

The determination of equilibrium climate sensitivity has been estimated by various independent means, such as the study of how past climate change has responded to estimated forcings, climate response in the aftermath of volcanic eruptions and yes, computer modeling. Most of those studies arrive at a sensitivity expressed as the final equilibrium temperature response after all feedback to fall somewhere in the range of 1.5C to about 6C. 2C to 4.1C is now considered the best estimate with about 2.8C most likely.

Those numbers are for one single doubling of CO2 or it's equivalent in additional radiative forcing.

If you think all the physical science which leads to the conclusion we have a problem on our hands is horses__t, then you must be unaware of the depth and breadth of the scientific basis for AGW. Computer modeling is a tool which helps scientists test how changing certain parameters affects climate in the long term. AGW is not based upon computer modeling, it is based on physics and the study of how past climates have changed and consequently how climate is likely to change in the future.

I highly recommend the following website if you wish to learn the history of how we came to understand why increasing atmospheric CO2 will cause a global warming: SEE