[Antarctic] Ice shelf collapse was unprecedented event in last 10,000 years

New Zealand Herald ^ | August 4, 2005

[Publius6961]

The author makes a pretty compelling argument that global warming is in fact part of the natural cycle and is the precursor for the cyclical onset of a new ice age. Man has little to nothing to do with it.

It shouldn't take much to mount a "compelling" argument.

Only a moron or a total fool can look at the graphs in post 88 and use the phrase "Climate Change" as an intellectual weapon.

And "climate change", of course, is the reincarnated silly advertising substitute for both "global cooling" and "global warming" which have continuously embarrased the bottom of our gene pool, some masquerading as scientists, for 50 years, now.

[cogitator]

Did you read post 77? It includes the abstract from the paper that inspired the article.

This excerpt: "Some smaller Antarctic ice shelves have undergone periodic growth and decay over the past 11,000 yr (refs 7-11), but these ice shelves are at the climatic limit of ice shelf viability(12) and are therefore expected to respond rapidly to natural climate variability at century to millennial scales(8, 9, 10, 11)."

The Larsen Ice Shelf was not quite as sensitive, hence it was more long-lived.

[cogitator]

I wasn't trying to be flip. The Holocene climate has been stable enough that it's possible to address the entire period at once. It would have been weird if the time-series had started 13,000 years ago; why choose a starting point that lies within the last glacial epoch? You'll note that the abstract for the paper repeatedly refers to the Holocene -- they weren't trying to address ice shelf characteristics in other periods, when the climate regime was significantly different than "modern-day", i.e., the Holocene.

[slowhandluke]

If you read the abstracts posted in #77, you'll see that the Larsen Ice Shelf was a "northern" shelf, and thus more sensitive to changes in global climate that the more southerly shelves. The Arctic vortex circulation, which contributes to the formation of the ozone hole, helps keep the actual continent somewhat more isolated from the trends in climate over the rest of the globe.

I did notice this in post #77,

We infer from our oxygen isotope measurements in planktonic foraminifera that the Larsen B ice shelf has been thinning throughout the Holocene, and we suggest that the recent prolonged period of warming in the Antarctic Peninsula region(13, 14), in combination with the long-term thinning, has led to collapse of the ice shelf.

The use of 'long term thinning' in combination with 'recent warming' begs the question of the relative impact of either. Long term thinning can't go on forever before a catastrophic break up event would happen, whether or not there is a temporary warming event. There's no discussion of why there's been long term thinning, but I'd guess that there was a warm event a long time ago (end of the last ice age, maybe) and it's just taken that long for the shelf to melt.

Maybe there's something there, but the conclusions stated in post #77 aren't clear about whether it's long term or short term effects that are the primary cause.