Monday
May122014
by 
Bishop Hill
Bishop Hill Knock me down
May 12, 2014 Climate: Surface Climate: WG2 Well this is a turn up for the books. A new paper by Rignot et al has looked at the West Antarctic Ice Sheet and found that it is going to collapse!
With disastrous consequences!
And it will be awful!
Terrible!
(But it could take a thousand years).
Update on May 13, 2014 by
Bishop Hill
Bishop Hill
Revkin's take on the paper is a bit calmer than most.
Reader Comments (45)
The government must raise a new green tax immediately! Won't they think of the children!!!
Mailman
The message by Obama was death by 2100 so who cares about 1,000 years hence.
CAGW is impossible to discern for the casual onlooker.
On a more serious note, are these clowns tied to the clowns from RC (Stig and co)?
Mailman
At the current rate of sea ice growth in Antarctica I'm more worried about ships never getting to Antarctic again.
https://sunshinehours.files.wordpress.com/2014/05/antarctic-sea-ice-extent-for-day-128-from-1979-infilled.png
The paper is less alarmist that your post would suggest ('significant' contribution to sea level in next 'decades', but no time scale for collapse), while the press release is more alarmist than your post suggests (a 'conservative' estimate 'centuries', not a thousand years).
Your post might be better highlighting this discrepancy.
Also, it would be good to work out whether the new measurements (yes, there is data in the paper) add anything to understanding of the West Antarctic ice sheet.
Also, I presume 'West Antarctic Pensinsula' is a typo.
JK, if you think the paper itself is 'less alarmist', try the Guardian's take on it. The usual screaming headlines to grab attention, then the 1,000 years 'estimate'. *Sigh*.
http://www.theguardian.com/environment/2014/may/12/western-antarctic-ice-sheet-collapse-has-already-begun-scientists-warn
All this while current Antarctic ice extent is at a record for the time of year. There's a word for them, but Bish' would snip it. I'll let you guess for yourself.
Better send that Australian guy back down there to investigate.
I hope it doesn't happen on a Tuesday, that would be inconvenient.
I gotta go with Goddards take on this.
Warmer waters melt ice at zero degrees, but freezes slightly less salty water quicker at -2 deg C?
Life is always easy when you can claim its 'going to happen ' long after your no longer around to be asked why it did not.
Its unfair to say those working in climate 'science' never learn , for they have certainly learned to make sure their predications of doom are so far ahead that they never have to answer for the BS they spouted in the first place , has they have been when they made the 'mistake' of using short time lines.
Still if you can 'know' the wind speed from a thousand years ago, 'knowing ' all the ice is going to melt a 1000 years from now is easy stuff.
It's fun being a skeptic you get to mock all the alarmist nonsense, Imagine being an alarmist and having to be serious about all the doom and gloom of every announcement.
Cheshirered,
Yes, I think the paper is less alarming that the Guardian coverage would lead you to believe.
I think it's worth highlighting that point.
Unless I've misunderstood, the main conclusion of the paper is 'We find no major bed obstacle upstream of the 2011 grounding lines that would prevent further retreat of the grounding lines farther south.' I think that assessing whether or not this is true would make a useful contribution to knowledge.
You say
but I just don't see what that has to do with the validity of the measurements or conclusions of the paper (or the press release, come to that). Unless, when you write 'Antarctic ice extent' you are referring to the mass of the Antarctic ice sheet as a whole, and not Antarctic sea ice? So far as I know it's only true of sea ice extent, but in that case I'm not really sure why you raise the point?
Will this wind be so mighty...?
@ JK.
I'm really comparing the timing and integrity offered up by a MSM paper, the Guardian, through a screaming headline that - if you read the full text, is clearly revealed to be materially misleading, with observed reality of a current record Antarctic sea ice extent.
Fact: Record ice extent for this time of the year.
Media claim: The ice sheet is melting and will raise sea levels 13 feet.
It's not surprising anymore coming from them, but it's pretty disgusting misdirection all the same. (In my opinion)
You can see the difference surely?
Clearly the Guardian and BusinessInsider etc did not read the papers but read a press release produced by the scientists. It would be interesting to see that press release to see who is responsible for the silly hype.
Anthony reports that Revkin has 'called out' the guardian. I wonder if any of our climate scientists will have the integrity to do so. Tamsin gave a talk on this very subject today.
I'm curious: if this is the ice sheet rather than the (record extent) sea ice, how can 'global warming' cause a melting let alone a collapse when temperatures are below freezing? (The latest recorded high at Casey Station in -9.4°C).
May 13, 2014 at 12:16 AM | Aynsley Kellow
I think their theory is that the glacier is being undermined by warm seawater and the grounding line (where the glacier becomes an ice shelf) is retreating landwards.
In their alarmist view, if this happens for long enough the whole glacier will launch itself into the ocean like a ship being launched. The 'slipway' is clear is my understanding of the 'no major upstream bed obstacle'.
It takes a special kind of feeble mentality to get into such a lather about something that might happen in 1,000 years' time.
It is also precisely the mentality which is the main criterion for the post of Environment Correspondent for The Guardian.
The end of the earth?
Not another doom laden scenario - again?
Gulp! Well, yes-siree.
The Antarctic western shelf, is a complex geological area, for obvious reasons investigation of the underlying geology is hampered but is a fascination and it's rather complicated, here's a simplified over-view from Penn state of all places.
"Intraplate hotspot" now, if things got going down there under the ice cap, that, would be a 'gas' and a half, fireworks galore! Plus, the emissions - aerosols and particulate matter - would probably blanket the earth for N years [who knows?]...................with a super volcano - and two cratons, moving around two plates, it's not a case of if - but when.
And lots of CO2 but none of it man made emissions.
A lot of people seem to think that ice only disappears when temps are above freezing. I once stayed in northern China in a city where temps were around -20°C for a week. If snowed about 250mm at start of week and by end of next week it was all gone through sublimation, without the temp rising above -15°C.
Changes in air humidity/dryness and snowing/sublimation will have far greater impact on ice loss or accretion in polar areas than than any relatively small volumes that fall off the edges sides.
Slightly warmer (but still sub zero) air holds far more water vapour and so increases rate of both snow deposition and sublimation - but the relative changes in rates of each is anybodies guess being based on localised and largely unknown climate changes equivalent to wetter/dryer cycles elsewhere.
"I'm curious: if this is the ice sheet rather than the (record extent) sea ice, how can 'global warming' cause a melting let alone a collapse when temperatures are below freezing?"
It's not really about global warming causing melting. It's about the balance between ice accumulation from precipitation in the middle of an ice sheet versus its loss around the edges (generally by calving rather than melting). Generally, the ice accumulation increases with the area of the ice sheet, while the rate of ice loss varies with the speed of the flow, and with the length and height of the boundary. When ice flows off an ice sheet into the sea, the depth of the sea at the point it starts floating defines the height of the boundary where it is considered lost. Deeper sea results in a greater thickness of ice crossing the boundary and hence more/faster ice loss. For a glacier with a constant width, the constant flow of ice from inland will result in the boundary advancing until the sea depth increases enough for the ice loss to balance it. If the sea bed is getting deeper as you move out from the coast, the ice extent is stable. Basically, it's a simple function of the rate.
But if the sea bed rises to a ridge as you move out to sea, you can get an unstable condition. The further the ice retreats, the more surface area is exposed to the sea at the boundary, and therefore the faster the ice is lost. This positive feedback triggers an unstoppable retreat until the sea bed at the boundary changes slope again.
There are a lot of difficulties with the model. It's not a constant flow rate - it tends to be highly non-uniform and turbulent across the edge of the ice sheet. The sea boundary is not a smooth line but a fractal, so the length as well as the height can change in all sorts of complicated ways. The slope and thickness can change unpredictably. The bed friction can change unpredictably. The precipitation inland will change unpredictably. It's not a simple process to model.
If it's the same paper I saw some days ago at WUWT, then it's arguably quite a handy 'pro-sceptic' paper, because it sets limits on the speed of any contribution to sea level rise, at somewhere around 1 mm/yr. Which is not particularly scary, and certainly a lot less scary than the claims that it might all collapse within the century, as some have suggested. I think there was some vaguely alarmist comment in the press release about how it would affect low-lying cities like New York and Mumbai in 5000 years time, but if those cities are still in their present form in 5000 years it'll be an even bigger surprise. However, I wouldn't necessarily accept the results of their modelling just because I liked the conclusion.
Mitigation: Assume this were for real. and there was genuinely 1cm/year of sea level rise from this process (4m over several centuries). That is about 3.6e8 x 1e-5 = 3.6e3 km³ per year.
That volume of sea water could be pumped up 2km in altitude into the centre of greenland or antartica to be frozen with a power input of about 2TW, which from 0.$05/kWh Nuclear power would cost about $100 million per hour or about 800 Billion per year globally. We could also (more cheaply) desalinate it and pump it into the middle of continents to fill up aquifers that are currently being depleted by irrigation.
That worst-case-scenario mitigation is about 1% of current $70trillion world GDP, but will be far less costly in future as the world gets richer and improved nuclear technology leads to cheaper power.
Not that I believe for a minute that it is likely to happen as the world heads into its next Milankovitch cycle driven glaciation, but nice way to pull the teeth of Alarmists with a relatively cheap scheme that we could use in future if sea level rise were actually a problem.
An ice sheet which studies has shown is transient in nature is possibly going to shift and melt in the next thousand years or so. And this shift is now unstoppable.
So we deal with this by taxing fossil fuels?
Sounds like a winner to me.
/sarc off>
Nullis in verba,
Thanks for the summary.
Do you mean that the ocean water flow is turbulent or the ice flow is turbulent? Turbulent ice flow would be very interesting.
I meant the ice flow is turbulent.
Yes, it's very interesting. But like most turbulent phenomena, very, very difficult.
This thing was broached on PBS News (US variation on BBC) this evening. The story was represented as emanating from NOAA (IIRC) and there was a NOAA person to answer questions. The questions weren't bad and went to the cause, "warmer water beneath he ice."
"And where is this warm water coming from?"
"...being blown there by changing wind patterns."
"Why are the wind patterns changing?"
"Well, climate change."
The NOAA guy was a true believer because he could have answered "Well, climate change, what else would it be?"
But. Alas, he didn't.
This is O/T but encouraging nonetheless - found in the Irish Times.
http://www.irishtimes.com/news/environment/warning-of-over-alarmist-stance-on-climate-risk-1.1792370
NASA video on WAIS, animation and commentary by Eric Rignot:
http://www.youtube.com/watch?v=mCPN7apYxh8&feature=player_embedded
I just realised I probably ought to clarify my last comment. Ice flow itself isn't generally 'turbulent' in the technical sense. A better word for what I was thinking of would be 'chaotic'. Ice flow isn't generally smooth and even on ice sheets, but gets concentrated into narrow, fast-moving channels, and breaks and flows unevenly. Apologies.
RobL: I knew of sublimation, but thought it would have to occur to an incredible extent to be in play here.
Nullius: very useful summary - though I think the irreversible loss of the ice sheet through these processes again seems to be drawing an unnecessarily alarmist bow of some length.
As reported on New Zealand TV news tonight the sea level will rise 4 feet by 2214. Further, on-going rise will take place over some centuries. The process is "irreversible" i.e. we are pass a "tipping point". And no recovery will commence for a thousand years. Which particualr media release they are using was not stated.
I still prefer chicken entrails to computer entrails because at least you get to eat the chiken afterwards.
It must be really serious, because it is on BBC News already.
Of course many climate scientist seers and their fanatical followers have reassured us that climate science predictions (or is it projections this week?) become more accurate the farther out they go...:
Did I dream of the report this,week on volcanic activity destabilising the ice sheet (Sunday Times)? The BBC did their usual duty this morning with a one sided report, wich failed once again that:
a) The sea ice this morning is,at record levels.
b) The satellite record used by NASA is,a mere 40 years of varying quality.
C) NASA themselves said that wind was the largest contributory factor not temperature. They alsp stated that it was Bangladesh and other low lying under- developed countries which were most in trouble.
Hyperbole all round as per usual
RobL (2:30 AM): like your idea of topping up aquifers with de-sal plants; but isn’t nature already trying to do that? That it should inconvenience us with flooding being one side-effect.
Somewhat off-topic, but the BBC had an interesting </sarc> piece this morning on people leaving food on their plates in restaurants; a psychologist managed to get in – twice! – that this could have an effect on climate change. Obviously knows on which side his bread is buttered.
(Note to self: login or preview before posting.)
Our old friend El Nino is involved here, in determining the ocean currents under this ice shelf, which in turn is influenced by winds, so expect much dark muttering about those dastardly greenhouse gases.
The question to ask is: How much time before "collapse" will we gain (or even lose) by reducing emissions of CO2? There will always be warm ocean currents regardless of what we do.
See here for a recent paper that looks at the influence of ocean currents in this area:
http://www.ccpo.odu.edu/~klinck/Reprints/PDF/dutrieuxScience14.pdf
"it could take a thousand years"
Should outlast the Grauniad, then.
Nullus In Verbia
Thanks very much for that lucid and clear explanation. I'll be using that if it's OK with you.
JK
I think the paper is less alarming
Maybe. But it is alarming and deliberately so. It takes no account of the current record level (28 yrs worth) and excludes many other possibilities for what they think they are seeing.
ALARMIST CRAP
Just to put the time frame in context...
Wikipedia informs me that Aethelred the Unready had just returned to claim the English throne and King Cnut has just returned to Denmark to enforce his rule there in 1014 AD. I doubt either would have had much sympathy for my opulent lifestyle way back then - even if they MIGHT be causing some environmental impacts which someone claimed could affect it.
http://en.wikipedia.org/wiki/1014
I'm sure the world and lifestyles will be a better, healthier, pleasant place in 3014 AD.
Ah - but the BBC (bless) had this as a news item on BBC Breakfast this morning (Tuesday) with NO MENTION AT ALL of the timescale, stating that it was 'irreversible', and the prediction that sea levels would rise 'up to a metre..'
Implication..? That it was all gong to happen very soon...
Lazy journalism or deliberate misinformation..? You choose, but remember its the BBC...
And - leading on from my previous posting above - BBC Breakfast had a guest on, - a psychologist I think - who managed to mention 'climate change' not once, but TWICE.... and the subject..?
Some restaurant in (I think) Holland that was planning to fine patrons who didn't eat everything on their plates..!
Yep - 'wasting' food causes climate change...
I see i screwed up my comment above. The guy was from NASA, not NOAA. PBS News comes on at the end of "childrens' hour" (see FDR for what constitutes "chlldrens' hour) and I was thinking of surviving the pending floods. Nuts.
aynsleykellow,
"Nullius: very useful summary - though I think the irreversible loss of the ice sheet through these processes again seems to be drawing an unnecessarily alarmist bow of some length"
They would say that, whatever the paper said. And in the short term, there's not a lot we can do about it. I more or less ignore what alarmists say nowadays - the movement is doomed, and what they say has lost much of its power to alarm. You don't need to counter it any more - it eventually counters itself. The longer term game though is to slowly build up credibility, and one way of doing that is to simply understand and state the situation as it is, whether it's favourable to scepticism or not. Michael Mann was the one who thought they shouldn't present the truth because it would give ammunition to the opposition. That's not an example we want to follow.
If there's a feasible mechanism for irreversible ice loss, then there is. Pretending otherwise would be counterproductive in the long run. But the timescales mean that it's essentially irrelevant for policy planning purposes. Getting the proper understanding and the information out there is what's important.
g1|gam3sh,
"Thanks very much for that lucid and clear explanation. I'll be using that if it's OK with you."
Sure, go ahead. But in retrospect I definitely shouldn't have used the word 'turbulent' in this context, so if you want to avoid someone picking up on it, change it to 'chaotic' or 'irregular' or something like that.