The Australian has carried its war on science another step, step 35 according to Deltoid. This time they have published an article Revealed: Antarctic ice growing, not shrinking by Greg Roberts, plus another Change is a cold certainty. If you’ve read my post on the Wilkins ice bridge I can tell you there is nothing new here, move on.
The first article is a muddle of mixing up sea ice east and west, ice sheets east and west, and not a mention of the Antarctic Peninsula. The second is more informative, but contains some straight errors. On the day I heard quoted scientist Ian Allison saying multiple times on the ABC that overall the continent was in fact losing ice. Harry Clark does a good job on these articles, on the Australian’s promotion of the Ian Plimer book and what he calls “a truly monstrous piece of distortion by Christopher Pearson.” Incredibly, Pearson sees Plimer as the watershed in the AGW debate:
As far as the progress of what passes for national debate is concerned, in all likelihood 2009 will be seen as the turning point and divided into the pre and post-Plimer eras.
But he is just warming up when he said that. Unless you particularly want to keep up with the antics of the Oz tribe, I recommend you give the whole thing a miss.
Of much more interest, I think, is an article in the New Scientist which states that “the West Antarctic ice sheet has collapsed and regrown over 60 times in the past few million years” and reports on a new technique studying how such events occurred.
This research involves drilling two holes into the conglomerate and mud at a point in the south-east of the Ross ice shelf. This image shows the drill point together with the elevation profile of the continent along the red line:
Figure 1: Andrill team drilling site in Antarctica
The Andrill (Antarctic Geological Drilling project) team are trying to reconstruct how the West Antarctic ice sheet (WAIS) collapsed and regrew with a view to developing a new improved model of ice sheet dynamics. They are particularly interested in how the warming water attacks the WAIS, the bedrock of which is largely under water. Richard Alley, who helped write the relevant section of the last IPCC report explains:
Those older models’ biggest weakness, he says, “is this business of warm water getting at the edge of the ice sheet and triggering changes that propagate inward”.
They have focussed on the Piliocene period, roughly 2-5 million years ago. They say in a paper published In Nature (behind the pay wall) that:
their model successfully reproduces the sequence of ice sheet collapses and expansions seen over the last 5 million years in the Andrill cores.
Along the way they had a look at what happened over 12,000 years about 1,080 million years ago:
Figure 2: Collapse and regrowth of WAIS from 1,084,000 years ago
They point out that when there was no ice sheet on West Antarctica CO2 levels were around 400 or 450ppm. DeConto and David Pollard of Pennsylvania State University are about to run their model into the future.
“I think that the numbers over the next 100 years or so are going to raise a few eyebrows,” DeConto warns.
Having cogitated on this issue for a while I’d venture a few comments.
During the middle of the period under study came the closure of the Panama Isthmus about 3 million years ago. While this is not as significant as the opening of the Drake passage between the Antarctic Peninsula and South America much earlier, which isolated the Antarctic continent, the joining of South and North America produced the important thermohaline circulation of modern times. I’m not sure how much difference that makes but it must be important in how heat is distributed around the planet.
Secondly, since the Pliocene we have been more in ice ages than out. During this time one would expect the East Antarctic ice sheet to have grown steadily. So the elevation should be higher and the ice sheet more stable than it was even a few million years ago. I suspect that the Greenland ice sheet (worth 7 metres of sea level rise) and the WAIS (5 metres) would proceed in tandem. After that further warming of a degree or a little more may not produce much decay in the EAIS (worth 57 mtetres). When it becomes seriously unstable, watch out.
It is probable, however, that if the WAIS collapsed completely there would be some significant net ice loss on the EAIS.
Finally, there is some comfort in the notion that the WAIS has collapsed and regrown 60 times in the past few million years while leaving the EAIS largely intact. The turnaraound happened with relatively mild climate forcings compared with what has been happening since mid last century. The notion that decaying ice sheets involve “runaway” processes is perhaps over-emphasised. Turning them around is no doubt difficult but it happened 125,000 years ago after a 4-6 metres sea level rise.
The Andrill research is to me a first step in getting a better handle on the processes of ice sheet decay and growth. It’s unlikely to be the last word.
In conclusion I’ll post an image of the subglacial topography I have used before:
Figure 3: Subglacial topography of Antarctica
The image is calibrated in feet. Blue is under sea level, green above. The Andrill team stress that WAIS is mainly about sea in contact with ice, the EAIS is about atmospheric processes.
Update: Here is an image of the sea ice extent and trends from The National Snow and Ice Data Center at the University of Colorado:
Figure 4: Antarctic sea ice September maximum 2008
Please note that Greg Roberts seems to give more credence to a Russian sea captain than to legitimate scientists.
I hope Brian that you will put all of this material in one publication one day soon.
Perhaps the way it plays out is that the Arctic collapses first raising sea levels by metres. This works to stress the southern floating ice physically and the increased circulation of water from the extra depth and surface area works on reducing that ice mass, which further increases the depth and surface exposure. Of course all of that cold lower salinity water flowing out of the arctic works to provide very variable Pacific Ocean weather conditions, which gives some news papers something to write home about, any way they choose. I think that we will be finding out how it works all too soon.
Hey Brian,
I was waiting for this post, after reading this article the other week. It is comforting… in a kind of “wow, sea levels will rise twice as fast as forecast over the next 100 years, but at least we shouldn’t end up in Waterworld(tm)” way.
On a completely OT topic, did you also see this article about solar storm predictions (following up on another of your recent ‘Doom’ threads). Now all we need is some kind of globally organised response protocol to protect our fragile power grids with less than 24 hours notice…
On The Royal Society (UK) site, there’s an interesting paper by James Hansen, Makiko Sato, Pushker Kharecha, Gary Russell, David W Lea & Mark Siddall
Climate change and trace gases More comprehensive than is usual, and meeting the RS’s famously rigorous scientific standards, it has a lengthy discussion on the Antarctic, ice-sheets, causes of palaeoclimate fluctuations and – a plus from my point of view – the much-ignored black carbon (carbon particulate build-up) of which they state:
Appended is an excellent bibliography.
There is also a series of “for Joe Public” (but still good) reviews of Antarctic ice & Climate Change on the ABC’s website (my link through Antarctic ice growth linked to ozone hole )
A quick review of current theories at every level from “top Class A international” to “for Joe Public” indicates that to say there are multiple, well-substantiated viewpoints on both “ice growing” and “ice melting” theories is a gross understatement! The jury is still out is the most accurate assessment, unless one is a disciple of a specific point of view.
Since 2004, there has also been a growing volume of research on coral re-growth (new & ancient) as temperatures rise (including rapid temperature rises), especially in Qld’s and the Caribbean’s tropical reefs. Like the Antarctic Ice debate, there are rigorous studies to show how resiliently coral adapts, even in rapid temperature rises; as there are equally serious studies of “doomed” coral. Far more than the Antarctic ice debate, this is descending into abusive, especially from “true believers” in the latter. The former has been supported by studies published this year, eg
Then there’s ‘Lucky escape’ for Barrier Reef coral
I read a similar one re research into cores of ancient Caribbean reefs with similar findings (?Huffington Post), but forgot to bookmark it & can’t find it.
As with the Antarctic ice controversy, the jury is still out on coral reefs, and whether global warming will see them adapt & regrow as the climate warms, or bleached & destroyed.
What’s worse about The Australian article is that it was based on a draft report (out for scientific comment), and there was no way one would pick the content of the article from a balanced summary of that draft.
Here is what I said to Philip Sutton in an email about the Andrill work:
To add a further note – the lot would not go this century but both could be far enough advanced that to stop it would be like trying to stop a bus with a tennis racquet.
The 400-450 ppm ice free scenario for the West Antarctic shelf (if we stabilised there) would, I think, be a slow process compared to a much warmer scenario because of the lag in feedback and warming processes. Melting may be avoidable in an overshoot scenario that hits 480-500 then drops substantially because of this lag. The 480-500 is the best we could do at the moment, without a global shift in a decade effort. However, none of this has been tested with good scientific models. The climate models are up to testing this, but not the ice sheet models (yet) with any confidence.
Anything we do from here (including nothing) is a massive gamble. Our policymakers should wake up to this fact.
Thanks, Roger, for your knowledge and insight, as always.
BilB, my stuff isn’t that good. And I have a day job, kind of.
Andos, I usually leave the antics of the Oz to Deltoid and others. But this one seemed relevant to other stuff I was interested in.
Thanks for the link. I get the dead tree version of the new Scientist. I swear there is more on the internet site than they print.
DeeCee, I looked at the Hansen article last year in relation to sea level change.
Thanks for the link to the Antarctic sea ice growth and the ozone hole. I’ve added an image of the September 2008 maximum at the end of the post above from the NSIDC in Colorado. I’m not sure what the controversy is. The overall sea ice growth isn’t much and it is reducing around West Antarctica and the Antarctic Peninsula, which are the areas of concern. And where the land ice is losing mass. What the Andrill research is telling us, it seems to me, is that the WAIS can collapse completely while the EAIS is relatively intact.
See also my Wilkins ice bridge post Figures 8a and 9.
I’d like to do a post on corals when I get time to research it more. From memory Ken Caldeira said that after each major extinction event corals took 4 million years to grow back into substantial reefs. So they are both fragile and adaptable and must have existed or at least survived in seas more acidic than the present.
Thanks for your posts, Brian; they keep my aging brain active. If I stumble over more of the research on corals, I’ll post them. I find most of the CC articles chasing the latest palaentological & ancient history research.
BTW: I think it bears emphasising that natural systems are in dynamic equilibrium; a state which copes with variations; often quite wide and/ or quite large and/or quite sudden. (As an example) Some European migrants to Australia had to cope with a very rapid shift from very cold to very hot climates: earlier settlers who moved from “Little Ice Age” UK, striking tropical heat usually within a month of leaving England, and Sydney’s blazing “Foundation Drought” summers within 10 months; German Kulturkampf migrants who came from mountainous German states to live in Brisbane’s Turkish Bath summers (Nundah). Horror stories about the fatal effects of rising global temperatures, therefore, ignore the fact that many of our own migrant’s stories show that humans adapt to much greater & more sudden climate change. Animals they brought with them – horses, sheep, cattle, dogs, cats, rabbits, foxes, deer, birds, fish etc – also rapidly adapted to the same hotter climate (too bl*ody well, in many cases).
One of the flaws I find in much CC “research” (and almost all hysterical beat-ups) is a false assumption that natural systems are in static equilibrium and that comparatively small and slow global warming will lead to mass extinctions; when all around them in Australia is overwhelming evidence that this is not so.
Yah, I was referring to the NS article on Andrill.
I, too, get the dead tree version but I can’t resist browsing the website too since once I read the magazine the news is generally 2 weeks old anyway.
A spirited ‘debate’ on ABC radio Breakfast show today between Plimer and coral specialist Dr Charlie Veron. It can’t be much fun taking on an emminent geology professor with creditable runs on the board vis-a-vis tackling Creationists, but Veron with only one hour’s access to ‘the book’ (Heaven and Earth) didn’t take a backward step. The book is now reported to be already into a third print run (15000) with an obscure Western Victoria publisher.
Bloody unfair on Dr Veron, and I don’t think he handled it too well, but eve so he came down to a key point straight away – where’s the peer review?
Dee Cee #6,
Actually, that construction on impacts is not quite right. These days dynamic equilibrium is out, and metastable, oscillating and chaotic are better descriptions of various states in complex systems. You’re right about high variability but this does not mean that large shifts in such systems are required to produce mass extinctions etc. It depends on how close that system is to a critical threshold or change of state. The rapidity of a shift is also important. Under global warming, many of the extremes will be shifted with the mean (the whole envelope of variability shifts) meaning that new extremes can result in signficant vulnerability.
You’re right to observe that some systems are resilient, but others aren’t. The “this has always happened to natural systems so they’re not vulnerable” is very close to one of the arguments that Plimer, for one, is running. The IPCC Working Group II Fourth Assessment Report (www.ipcc.ch and follow the links) contains many reasons as to why this is not a sound assumption. Many human systems are also not resilient to even small shifts. The European heat wave in 2003, recent extreme fires in SE Australia, and communities vulnerable to glacier instability are good examples.
What I think you’re seeing in the media is a conservative view that all observed changes are bad. Often a better ecological and environmental understanding can help interpret whether this is true or not – and sometimes we just don’t know.
Humans are one of the most adaptable pests on the planet, but many of our systems that exist in large variability today appear to be quite vulnerable to even small shifts. Water infrastructure in south-eastern Australia is a further example (I’m not attributing these shifts – just using them as illustrations).
I don’t think you’ll find too many assumptions of static equilibrium in the serious refereed literature. Surviving examples should be dwindling and should be rejected unless a transparent assumption is made because dynamic methods are not available.
wiful, I thought Charlie Veron did quite well. See my comment on the other thread.