NRT: Climate change: Point of no return

Written By: - Date published: 1:18 pm, May 14th, 2014 - 26 comments
Categories: climate change, science - Tags: , , ,

no-right-turn-256As has been (long) anticipated under current conditions the West Antarctic Ice Sheet will melt with a more than average 3 metre rise in world sea levels. The only remaining question is how long it will take to melt. No Right Turn explains the slowly unfolding disaster…

A key goal of international climate change policy, expressed in the UNFCCC, has been to “prevent dangerous anthropogenic interference with the climate system”. For the past 20 years, that has been interpreted as limiting temperature increase to no more than 2°C beyond pre-industrial levels. All our modelling on emissions reduction has been focused around meeting this goal.

Yesterday, we found out that its not enough, with two papers reporting that the West Antarctic icesheet was already beyond the point of no return and would collapse:

A disaster may be unfolding—in slow motion. Earlier this week, two teams of scientists reported that the Thwaites Glacier, a keystone holding the massive West Antarctic Ice Sheet together, is starting to collapse. In the long run, they say, the entire ice sheet is doomed, which would release enough meltwater to raise sea levels by more than 3 meters.

One team combined data on the recent retreat of the 182,000-square-kilometer Thwaites Glacier with a model of the glacier’s dynamics to forecast its future. In a paper published online today in Science, they report that in as few as 2 centuries Thwaites Glacier’s outermost edge will recede past an underwater ridge now stalling its retreat. Their modeling suggests that the glacier will then cascade into rapid collapse. The second team, writing in Geophysical Research Letters (GRL), describes recent radar mapping of West Antarctica’s glaciers and confirms that the 600-meter-deep ridge is the final obstacle before the bedrock underlying the glacier dips into a deep basin.

Because inland basins connect Thwaites Glacier to other major glaciers in the region, both research teams say its collapse would flood West Antarctica with seawater, prompting a near-complete loss of ice in the area. “The next stable state for the West Antarctic Ice Sheet might be no ice sheet at all,” says the Science paper’s lead author, glaciologist Ian Joughin of the University of Washington (UW), Seattle.

What does 3 metres of sea-level rise mean? Hot Topic puts it succinctly: “we are going to have to say goodbye to the current coastline and everything built there”. The timescale is long (though as we’ve found in the past, these things tend to speed up when we start looking at them closely), but in just a few human lifetimes, much of humanity is going to have to move.

And before anyone takes this as an excuse to simply give up trying to stop it, remember: this is one of the mild effects of human-induced climate change. Imagine what we’ll get if we raise the temperature by the 3 or 4 degrees currently predicted for “business as usual”…

 

antartica ice sheets melting

26 comments on “NRT: Climate change: Point of no return”

  1. NZ Groover (A lazy fool) 1

    Let me guess…….this is based on computer modelling?

    [lprent: No. This is largely based on the ANDRILL cores, which is why I linked to that twice in the post.

    At least try not to look like a completely lazy fool – attempt to read the links to the physical evidence so you don’t appear to be quite as much of a complete dickhead as you look now.

    The computer modelling part is the uncertain part in that they are unsure if the collapse will happen in a few decades through to a few hundred years. The reason is that the evidence about how fast the previous collapses were is somewhat uncertain as it is hard to see back that many thousands of years.

    I have amended your handle to reflect your actual abilities. ]

    • just saying 1.1

      If you are over 30 you’ve experienced climate change for yourself and you are aware of it happening around you in the weather at home and from reports from abroad. No matter how well you can change the subject in your head, you know.
      Either that or you’re pig-ignorant

      • Pip 1.1.1

        yes but “Might” “Could” “in the next 1000 years” and “Man did it” and of course “Guess”

        Climate change is real. Man didn’t do it. Not in the short time frame that you’ve been lead to believe. Say since the Industrial revolution.

        Didn’t help, but there is not a lot we can do except adapt to a system that we don’t have domain over, despite the ” man is the centre of all thing” philosophy

        • One Anonymous Bloke 1.1.1.1

          What a load of nonsense. Where is the extra atmospheric CO2 coming from? Why does it show an isotopic signature consistent with fossil-fuel origins?

          Oh, I accept that you have an utterly self-centred and arrogant philosophy, however.

        • joe90 1.1.1.2

          Man didn’t do it.

          But we may be helping things along.

          In recent years, there has been growing evidence for the hypothesis that the effect of the pandemics in the Americas wasn’t confined to killing indigenous peoples. Global climate appears to have been altered as well.

          Stanford University researchers have conducted a comprehensive analysis of data detailing the amount of charcoal contained in soils and lake sediments at the sites of both pre-Columbian population centers in the Americas and in sparsely populated surrounding regions. They concluded that reforestation of agricultural lands—abandoned as the population collapsed—pulled so much carbon out of the atmosphere that it helped trigger a period of global cooling, at its most intense from approximately 1500 to 1750, known as the Little Ice Age.

          http://news.stanford.edu/pr/2008/pr-manvleaf-010709.html

        • Colonial Viper 1.1.1.3

          Climate change is real. Man didn’t do it. Not in the short time frame that you’ve been lead to believe. Say since the Industrial revolution.

          Do you really believe that we can continue to exploit nature at ever increasing scales and not suffer physical payback?

          These things can happen fast. A volcano eruption can block out the sun and cause measurable cooling across a continent within days.

        • Sid 1.1.1.4

          Typical Denialist response. Just look at the stats and see the trend since the 1970’s.

          But evidence is just another conspiracy! Your offspring will have to address the problem but you don’t appear to care!

      • Will@Welly 1.1.2

        well said. some, like nz glover just want to bury their head in the sands. trouble is, soon, they’ll all be under water.

    • RedLogix 1.2

      Let me guess … your wouldn’t know what a computed model was if it bit you in the arse?

    • One Anonymous Bloke 1.3

      Let me guess, NZ Groover has never heard of George Box.

    • Ennui 1.4

      I really do admire Climate Change Deniers. They have an ability to totally miss what is so obvious that it is stunning. A quite brilliant level of myopia.

      Here we are living in a world of corporate controlled media, the people who have many reasons to promote denial. Look at how much oil companies spend on promoting activities that create global warming. And yet those empirical studies by multiples of scientists have infiltrated the smokescreen of self interest. The scientists have beaten the propaganda machine.

      Now if you are in denial try and refute something that has outfoxed even the best spent corporate money for spin.

  2. silverbullet 2

    @NZ Groover

    Let me guess…you believe that Jesus rode to school on a dinosaur?

  3. Roy 3

    Most climate change skeptics I know are old people. It’s not going to be their problem and apparently they don’t care about their descendants.

  4. hoom 4

    I’m sure the Coal, Oil & Nuclear energy companies have a plan.

    Something like Meltwater Sequestration®

    All you need to do is pump it underground or put it in big tanks where bacteria can absorb it & we’re all good to go.
    Just a few technical details to sort out, Coming Real Soon™ in a couple of years uh decades er centuries or never…

    • Roy 4.1

      They will move to higher ground. Too bad about everyone else…

    • Colonial Viper 4.2

      I’m sure the Coal, Oil & Nuclear energy companies have a plan.

      Not sequestration. The fresh meltwater will be sold at $10/L to cities whose water supply has been contaminated by fracking. Cause the problem, then profit from it. It’s a corporate shareholders’ heaven.

      Water will become more expensive than oil.

      • Ennui 4.2.1

        Quite like the idea of water becoming more expensive than oil. I am actually suspicious of the cost of water given top farmers in NZ..if they had to pay the real cost they might not use it.

        Its going to be somewhat amusing (in a black humour sort of way) to watch their last oil being used by the Saudis to bring in water and food to supplement their local production of dry water wells and two sesame seeds and a camel stew. All that to support an out of control population growth. The same fate in a myriad of different ways awaits all of us. Interesting times indeed.

  5. joe90 5

    East Antarctic ice could well be on the move too.

    “East Antarctica’s Wilkes Basin is like a bottle on a slant,” says lead-author Matthias Mengel, “once uncorked, it empties out.” The basin is the largest region of marine ice on rocky ground in East Antarctica. Currently a rim of ice at the coast holds the ice behind in place: like a cork holding back the content of a bottle. While the air over Antarctica remains cold, warming oceans can cause ice loss on the coast. Ice melting could make this relatively small cork disappear — once lost, this would trigger a long term sea-level rise of 300-400 centimeters. “The full sea-level rise would ultimately be up to 80 times bigger than the initial melting of the ice cork,” says co-author Anders Levermann.

    http://www.sciencedaily.com/releases/2014/05/140505104435.htm

    http://www.discoveringantarctica.org.uk/alevel_1_4.html

  6. ghostwhowalksnz 6

    The map image provided isnt related to the research mentioned. The Weddell Sea ( Ronne Ice shelf )and Ross Sea shelf are not mentioned.

    This would be a better map with the Twaites and Pine Island glaciers shown

    http://news.nationalgeographic.com/news/2014/05/140513-west-antarctica-winds-glaciers-melting-global-warming-science/

    As an aside, the glacier retreat research is based on computer modelling…

    To forecast Thwaites Glacier’s fate, the team plugged satellite and aircraft radar maps of the glacier’s ice and underlying bedrock into a computer model. In simulations that assumed various melting trends, the model accurately reproduced recent ice-loss measurements …”

    The important part is the match to recent measurements

    • ghostwhowalksnz 7.1

      Not really. Sea ice is related to surface temperature.
      The research refers to the deep ocean up welling of (slightly) warmer water from deep ocean currents that circulate around the globe

    • NickS 7.2

      🙄

      Sea ice locks up not a hell of a lot of water compared to what’s going to be likely lost from the ice sheets in Antarctica…

  7. Bill 8

    The video links to this on the Hot Topic piece are worth watching ( http://hot-topic.co.nz/pig-and-pals-pass-point-of-no-return-west-antarctic-ice-melt-inevitable/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+co%2FRbRF+%28Hot+Topic%29 ). In one of those videos, the researcher was saying that the collapse could take as long as a couple of hundred years at present rates of melting. (a few km per year)

    Thing is… the. rate. will. in. crease.

    Everything to do with AGW is exponential, meaning that the supposedly pessimistic few hundred years is probably a fairly groundless positive prediction.

  8. Jenny 9

    The Human Cost of Coal

    Another Coal Mining Disaster

    Coal Mining Family suffers further tragedy

    Once they sent children down coal mines.

    Maybe it is time to stop sending Adults down there as well?

    Worse than Asbestos, Coal is the deadliest mineral we mine.

    Time to ban coal mining?

    And before all the fossil fuel luddites raise a chorus of screams about jobs.

    Let them be reminded that New Zealand once had a thriving mining and fabricating Asbestos industry employing thousands. Asbestos Harvey Planks, tiles and sheeting were ubiquitous in the building industry, we even exported it to the Islands and Australia. Even today the legacy of our Asbestos industry contaminates landfills in paradise, and even uncovered in backyards in South Auckland.

    The future is not in coal.

    Time for something new

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