So far it does appear that the current sea-ice area status is very close to what it was last year at this time. Also note, that the ice area in the Arctic Basin last year saw its greatest drop between the second week of July and third week of August. We may get some clues starting in the next few weeks.

What has the scientists scratching their heads is why this appears about to happen in the middle of winter. When the last Larsen ice shelf collapsed it was at the end of summer. The thought is that the warmer waters are chewing it up from underneath. This would highlight that what happens on the surface in winter is not the most important thing.

George Bush surprised world leaders with a joke about his poor record on the environment as he left the G8 summit in Japan.

George Bush proves to be quite an entertainer

The American leader, who has been condemned throughout his presidency for failing to tackle climate change, ended a private meeting with the words: “Goodbye from the world’s biggest polluter.”

He then punched the air while grinning widely, as the rest of those present including Gordon Brown and Nicolas Sarkozy looked on in shock.

http://www.telegraph.co.uk/news/worldnews/2277298/President-George-Bush-%27Goodbye-from-the-world%27s-biggest-polluter%27.html?funny=not

This man has a red button on his desk.

Two reasons are suggested. First, Antarctica is very dry. Gore’s book says that precipitation is less than 25mm per annum. Warmer surrounding waters may increase precipitation. Second, the ozone hole, which is far from fixed, is thought to have tightened the circulation patterns over the South Pole.

Dan, it’s my impression that what happens in winter is as may be, but what happens in summer is more significant. Also there have been constant reports on the BBC in the past day or so that the Wilkins ice shelf is hanging by a thread. So we’ll see how it all develops.

On the Arctic, it was generally expected that 2008 might pull back a bit from the big melt in 2007, just as 2006 was better than the record melt of 2005. But have a look at the third image in this post. That was a month ago.

Also the image in this article which I think was taken about a month later in the season seems to show a lot less ice in 2007 than the image you linked too. I think it’s a bit early to tell what the outcome for 2008 will be.

Today I heard a program on the Carteret Islands. Generally speaking the water is piling up a bit, or rather it is warming more and hence expanding more in the Western Pacific. They were suspecting El Nino, but amazingly that caused the water to go down considerably, from memory about 20cm. But they thought the El Nino might still be a problem, because of the effect it had on sediment transport.

I guess it goes to show how complicated things are.

Today in the Fin Review there was a story of the enormous wheat plantings this year. I worry that it’s going to come to grief.

BTW I’ve added an update to the post showing this image of Antarctica, meant to show how it was 35mya with isostatic rebound when it was ice free, with adjustment for sea level. Not quite the same as now, but it indicates where the problem is with West Antarctica.

So the interesting information you contribute is simply irrelevant, as far as I can see.

Roger and Barry, special thanks for contributing your expertise to our little blog.

Barry, the study Lynas mentions on fossil plants in the Transantarctic Mountains is by Francis and Hill, the very one you link to.

The implications Australian rainfall are particularly grim. This expansion is predicted by the current crop of Global Climate Models (GCMs), but they forecast a ~2 degree latitudinal expansion during the entire 21st century. Turns out, based on a analysis of a number of different meteorological features, that there has been closer to a 3 degree north and south expansion within just the last 30 years.

This tropical expansion is one of the principal drivers of the GCM-predicted decreased rainfall, of 10 to 40%, for southern Australia, western USA, southern Mediterranean Europe and South Africa. Unfortunately, it seems somewhat more likely now that tomorrow decided to make a house call today instead…

A recent meta-analysis and some comments on this can be found linked here:
http://www.aussmc.org/Tropics_expand.php

Regarding trees in Antarctica, a palaeobotanist colleague of mine at the University of Adelaide was one of the first to show clear fossil evidence of conifers (pines) growing along the Transantarctic Mountains during the mid-Pliocene about 3-2.5 million years ago.

http://palaios.sepmonline.org/cgi/content/abstract/11/4/389

At that time global temperatures were 2-3 degrees warming than present (a low-range projection for the 21st century). Sea levels were 25 m (give or take 10) higher than present – no prizes for guessing where most of that sea level contribution came from – Greenland, West Antarctica, thermal ocean expansion and a partial melt of East Antarctica.

Note that for Brian’s first slide, those temperatures are derived from polar ice core proxies (oxygen isotopes) and so are ~twice global temperatures. Globally averaged, the different between the depth of an ice and and a warm interglacial such as the Eemian was about 6C.

Things are going to change, they always have. The crazy people are the ones who believed they wouldn’t, and I suspect the real crazy ones are the ones that believe we can stop it. Perhaps the monkeys that built freeways will survive, perhaps they won’t. Time will tell.

Peter W I heard about that paper on the radio today so thanks for the link.

Have you ever seen any subglacial maps of west Antarctica and Greenland that show depth, all the maps that i have seen have simply shown the shapes of the land masses above the water line.

dylwah, I’ve seen both but unfortunately didn’t bookmark them and when I tried to find them again I couldn’t. The Greenland one was reconstructed by a blogger.

I have read recently that the middle of Greenland is about 300m below sea level, but is some of that is due to the weight of 3 kilometers of ice. Antarctica has 4 kilometers of ice, so there is plenty there.

Hey, I’ve just found one for Antarctica. Still can’t find one for Greenland.

good post and summary.

For a feel on how moulins may operate in a land-based ice sheet, think of a karst (limestone) landscape. The moulins are equivalent to sinkholes. The landscape opens up along fractures between weak points as stresses caused by altered loads due to melting have an influence. Underground rivers link sinkholes. Then the landscape becomes canyoned with occasional mesas before breaking up completely. Except, with ice, it’s much faster, taking years instead of millions of years.

A grounded ice-sheet below sea level (e.g. West Antarctica) will behave somewhat differently, because of the possibility of it becoming afloat and melting from above and below. Breaking up in sections similar to recent ice sheet collapses (Larsen B) is the MO in that case.

Partial melting of Greenland is an option if we miss the melting threshold but can moderate subsequent warming:

Amount of CO2 emissions irreversibly leading to the total melting of Greenland
Charbit, S.; Paillard, D.; Ramstein, G.
Geophys. Res. Lett., Vol. 35, No. 12, L12503
http://www.agu.org/pubs/crossref/2008/2008GL033472.shtml
The long-term response of Greenland to anthropogenic warming is of critical interest for the magnitude of the sea-level rise and for climate-related concerns. To explore its evolution over several millennia we use a climate-ice sheet model forced by a range of CO2 emission scenarios, accounting for the natural removal of anthropogenic CO2 from the atmosphere. Above 3000 GtC, the melting appears irreversible, while below 2500 GtC, Greenland only experiences a partial melting followed by a re-growth phase. Delaying emissions through sequestration slows significantly the melting, but has only a limited impact on the ultimate fate of Greenland. Its behavior is therefore mostly dependent on the cumulative CO2 emissions. This study demonstrates that the fossil fuel emissions of the next century will have dramatic consequences on sea-level rise for several millennia.

Unfortunately the full article is only available to subscribers