[Tanada]

$this->bbcode_second_pass_quote('Cid_Yama', '[')url=http://neo.sci.gsfc.nasa.gov/Search.html;jsessionid=23BE072D47BC3B1A73F4C9C4C1EF86BD?coverage=global&duration=day&startMonth=&startDay=&startYear=&endMonth=&endDay=&endYear=&sourceDatasetId=&maxLat=&minLon=&maxLon=&minLat=&size=full&palette=rgb&format=JPEG&w=&h=&ssn=&ssw=&sse=&sss=&datasetId=CERES_INSOL_E&x=33&y=10]Solar insolation data[/url]

[Tanada]

For those following this thread I highly recommend the brief paper on Glaciation and climate change you can find HERE.

Please pay close attention to the graph on page 11, it shows continental type glacier formation begins when summer insolation falls below a critical value of about 455 or 457 W/m^s, and every time the critical insolation exceeds 470 W/m^2 or so the ice sheets melt. Depending on how large the ice sheet is the lag between exceeding 470 and onset of melt changes, the greater the glaciation the more time it takes.

Zooming in on Greenland in the link Cid_Yama supplied above it appears that from June 26 to July 3 most of the island ranged from 410 to 550 W/m^2. If you now turn to page 13 of the document I linked too above and look at our current CO2 levels you will see that the critical value has decreased from 457 to 440, which places a lot more of the island in the deglaciation range than it would be without the CO2 forcing we already have in place today. If we add another 50% to our current CO2 levels which would place us around 550 ppm then the critical insolation value falls below 410, and ice on all of Greenland would become a melt situation. If you add in the forcing from other GHG components we are already past 450 ppm equivalent. That lowers the critical insolation threshold down to about 430 W/m^2

I think Greenland is at or above threshold now, or it will be in the very near future. How fast can it all melt? Nobody knows.

[katkinkate]

$this->bbcode_second_pass_quote('Snowstorm', '.').. Climate change may just make Greenland may be one of the best locations to be for peak oil, ever increasing growing season and land area from melted glaciers. ...

[dohboi]

Thanks for the link, tanada. I'll look into it more deeply when I have some time.

The dynamic that seems to be playing a large role in the melt is black carbon (soot).

Here as elsewhere, it turns out that GHG caused warming is acting as a trigger setting off powerful feedbacks.

As I understand it, the warming from AGW makes it likely that at least all of last year's snow/ice melt. This brings to the surface of the snow all the soot that was mixed in from the last year (at least). Now the albedo of the surface has changed to something darker that it would have been with out the initial melt. This increase in heat retention from the added surface darkness further accelerates the melting, bringing yet more soot to the surface as the snow melts around it...so you have an accelerating dynamic.

A recent study reviewed over at realclimate concluded that this change in albedo from soot accumulating at the surface (once AGW kicks off the process) accounts for most of the current melting.

Another thing affecting the lower altitudes that will accelerate as the Arctic sea ice melts is increased rain. On the other hand, increased snow may have a dampening effect.

[Tanada]

New video report here. It now seems that the ice sheet is shrinking 1.5 meters per year in altitude around the southern periphery.

[Homesteader]

When viewing the video it was a bit of a shock to see the layer of black particulates on the ice.

[Cid_Yama]

The quote, "just 10 years ago, the ice sheet was 45 feet higher than it is today." says all that needs to be said.

[Lore]

I don't get it? The climate was suppose to be cooling for the last 10-years. Why the ice-sheet melt... go figure?

[dissident]

The ice sheet melt should be drilled into the public mind at every opportunity. The denialist idiots like to bleat about 1998 being the warmest year and that there has been cooling ever since. Well, the melting ice cube picture is something simple enough for people to visualize and understand. Can't have melt without warmer temperatures and there is no way around this (forget about soot since air quality has been improving quite a bit). The ice is a great indicator that filters out the meaningless variability that is endlessly cited as explaining everything by the denialists.

[rangerone314]

I kind of wish the ice sheets would undergo a rapid melt that would actually start seriously flooding a few coastal areas, like Shanghai and New York. It might serve to elevate people's thinking a little.

[eXpat]

NASA data: Greenland, Antarctic ice melt worsening
$this->bbcode_second_pass_quote('', 'W')ASHINGTON – New satellite information shows that ice sheets in Greenland and western Antarctica continue to shrink faster than scientists thought and in some places are already in runaway melt mode.

British scientists for the first time calculated changes in the height of the vulnerable but massive ice sheets and found them especially worse at their edges. That's where warmer water eats away from below. In some parts of Antarctica, ice sheets have been losing 30 feet a year in thickness since 2003, according to a paper published online Thursday in the journal Nature.

Some of those areas are about a mile thick, so they've still got plenty of ice to burn through. But the drop in thickness is speeding up. In parts of Antarctica, the yearly rate of thinning from 2003 to 2007 is 50 percent higher than it was from 1995 to 2003.

These new measurements, based on 50 million laser readings from a NASA satellite, confirm what some of the more pessimistic scientists thought: The melting along the crucial edges of the two major ice sheets is accelerating and is in a self-feeding loop. The more the ice melts, the more water surrounds and eats away at the remaining ice.

"To some extent it's a runaway effect. The question is how far will it run?" said the study's lead author, Hamish Pritchard of the British Antarctic Survey. "It's more widespread than we previously thought."

[VZR1800]

$this->bbcode_second_pass_quote('rangerone314', 'I') kind of wish the ice sheets would undergo a rapid melt that would actually start seriously flooding a few coastal areas, like Shanghai and New York. It might serve to elevate people's thinking a little.

[dissident]

And the lemmings keep on running to the cliff....

[VZR1800]

$this->bbcode_second_pass_quote('dissident', 'A')nd the lemmings keep on running to the cliff....

[Cid_Yama]

It may be that those who have been right all along would just like to have the opportunity to rub their noses in it before we all die.

Unfortunately you will have the media going on and on about how 'no one knew' or 'no could have possibly known' or 'it was just impossible to predict' even though many of us have been warning about this for years.

Frankly, I get my satisfaction in knowing that they will suffer the consequences of their actions, that no one skates on this one. Perfect Dharma.

[Tanada]

$this->bbcode_second_pass_quote('rangerone314', 'I') kind of wish the ice sheets would undergo a rapid melt that would actually start seriously flooding a few coastal areas, like Shanghai and New York. It might serve to elevate people's thinking a little.

[Lore]

$this->bbcode_second_pass_quote('VZR1800', '')$this->bbcode_second_pass_quote('dissident', 'A')nd the lemmings keep on running to the cliff....

[DryObserver]

Try painting all of the asphalt roofs and roads white, thereby changing the albedo for a substantial part of the Earth's surface (that is presently dark gray to black). That won't stop everything, but if you start in warmer cities and towns you can break the "heat island" effect that afflicts urban areas, thus reducing air-conditioning demand (and its associated emissions). That will help save money that can be used to paint more dark roofs and roads in those regions. Once you're done with those cities, whether Barcelona or Baghdad, Atlanta or Athens, Madrid or Miami, move on to others. Assuming the North Atlantic Current doesn't fail and we don't get a snap ice age (really about the happiest outcome you could get in a true runaway heat up of the planet), then we'll have other balmy candidates soon enough.

And yes, I have been talking about that suggestion one on and offline for a couple of years now and yes, Dr. Steven Chu (Energy Secretary and Nobel Laureate) has also been talking it up of late. But in the meantime, there it is.

[DrGray]

$this->bbcode_second_pass_quote('DryObserver', 'T')ry painting all of the asphalt roofs and roads white, thereby changing the albedo for a substantial part of the Earth's surface (that is presently dark gray to black).

[lowem]

Painting the roads in any shade is crazy - it would wear off immediately.
Just about as crazy as solar or conductive roads.