New Video: Meltwater Pulse 2B

June 2, 2014

Today’s news will be dominated by discussion of new carbon regulations proposed by the Obama administration.  My contribution is to summarize the most recent evidence for why those regs are needed today, if not 25 years ago.
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Bud Ward at Yale Climate Connections:

It’s not often that a scientific research paper generates the kind of media attention and scientific community buzz that resulted from a recent study on the apparent inevitability of substantial Antarctic glacial melting.
The early May research headed by lead author Eric Rignot of NASA called attention to melting now under way in Antarctica that CBS News anchor Scott Pelley reported “cannot be stopped.”

“Scientists say the situation is almost certainly unstoppable,” NBC News Anchor Brian Mitchell reported.

Rignot cautioned that the research indicates “we’ve passed the point of no return … It’s just a matter of time before these glaciers disappear to the sea.” While he indicated that the full melt, at the current pace, might not occur for two centuries, he pointed too to evidence suggesting the likelihood of an accelerating pace.

rignot

“There’s probably nothing that can be done to stop this,” Rignot said.

“This is really happening,” lead NASA lead polar ice researcher Tom Wagner said. “This weak underbelly of Antarctica is in fact starting to float out into the sea, and there’s not a lot to hold it back.”

A “This is Not Cool” video on the report by independent videographer Peter Sinclair is the first to be posted under the new Yale Climate Connections name, formerly The Yale Forum on Climate Change & The Media. The official transition to that newly named site is to get underway over the next few weeks, initially with a largely cosmetic rebranding, then to be followed by a substantial overhaul and a more multi-media emphasis aimed at better reaching the general public.

Note: link to the Guardian piece referenced in the video is here. Errata – I neglected to thank the European Space Agency for important video animations. Deepest apologies.

UPDATE: Per Stefan Rahmstorf, newly published study adds complexity.

eScience News:

“Conventional thinking based on past research is that the Antarctic Ice Sheet has been relatively stable since the last ice age, that it began to melt relatively late during the deglaciation process, and that its decline was slow and steady until it reached its present size,” said lead author Michael Weber, a scientist from the University of Cologne in Germany.

“The sediment record suggests a different pattern — one that is more episodic and suggests that parts of the ice sheet repeatedly became unstable during the last deglaciation,” Weber added.

The research also provides the first solid evidence that the Antarctic Ice Sheet contributed to what is known as meltwater pulse 1A, a period of very rapid sea level rise that began some 14,500 years ago, according to Peter Clark, an Oregon State University paleoclimatologist and co-author on the study.

The largest of the eight episodic pulses outlined in the new Nature study coincides with meltwater pulse 1A.

“During that time, the sea level on a global basis rose about 50 feet in just 350 years — or about 20 times faster than sea level rise over the last century,” noted Clark, a professor in Oregon State’s College of Earth, Ocean, and Atmospheric Sciences. “We don’t yet know what triggered these eight episodes or pulses, but it appears that once the melting of the ice sheet began it was amplified by physical processes.”

The researchers suspect that a feedback mechanism may have accelerated the melting, possibly by changing ocean circulation that brought warmer water to the Antarctic subsurface, according to co-author Axel Timmermann, a climate researcher at the University of Hawaii at Manoa.

“This positive feedback is a perfect recipe for rapid sea level rise,” Timmermann said.

Some 9,000 years ago, the episodic pulses of melting stopped, the researchers say.

“Just as we are unsure of what triggered these eight pulses,” Clark said, “we don’t know why they stopped. Perhaps the sheet ran out of ice that was vulnerable to the physical changes that were taking place. However, our new results suggest that the Antarctic Ice Sheet is more unstable than previously considered.”

 

 

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18 Responses to “New Video: Meltwater Pulse 2B”

  1. dumboldguy Says:

    Excellent video—-great graphics and a nice reprise of Hansen’s now-coming-true prophecies.

    So we in the U.S. are now going to get into a huge fight about cutting emissions from coal-fired power plants by 30% by 2030? Only cut by 30%? By 16 years from now? And replace a lot of that coal with natural gas?

    In the meantime, CO2 keeps rising, the earth continues to warm, the bad things that are happening right now accelerate, and new “surprises” like west Antarctica appear. Why don’t more of us agree with McPherson?

    • rayduray Says:

      Re: “Why don’t more of us agree with McPherson?”

      Hint. Read the comments at Nature Bats Last. Half of the crew there seem ready to commit seppuku to avoid the pain of living in the future. It’s a bit of a dreary world view, eh? 🙂

      I’ve corresponded a bit with Dr. McPherson and he’s a stand up guy. I was hoping to arrange to have him come here for a lecture. To my disappointment I discovered that of the eight key fellow activists I contacted about the idea, seven knew nothing of Guy’s work and the eighth went apoplectic that I’d even consider bringing such a Cassandra-like figure to town.

      McPherson is an acquire taste, one you and I happen to find intellectually stimulating, but most people are like the ordinary man Winston Churchill caricatured by saying ” Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing had happened.”

      And I’ve just discovered a new Churchill quote that’s equally marvelous as regards Guy’s message:

      ” The squeaky wheel may get the most oil, but it is also the first to be replaced.”

      There now, it’s back to Bill McKibben’s message of hope and salvation… tomorrow. 🙂

    • redskylite Says:

      I agree that this is a brilliant video, with so many distinguished speakers and sobering message of unstoppable melt. What I have seen of Mr McPherson he is not a good spokesman, his position is that we are truly f*******d, but he takes some views that other science is wasting time and money, CO2 is in huge cycles that last for many many millenniums, while CH4 is more potent but is short lived. Yes it might trigger more tipping points we are in fire-fighting mitigation mode, and this summer has already taken a toll of human life in Japan, China and Pakistan. I hope this is the year that finally silences all those who deny, and we can seriously tackle the inevitable.


    • McPherson is indeed right that the current path is seriously hampering our planets ability to carry life, but the rate of change is somewhat out of whack. I believe his theory is that warming and CO2 uptake in the oceans happen in such a rate that it will seriously affect marine biology, the bottom of the food chain – and hence have repercussions up to anything bigger. The big one is ofc Phytoplankton which is in fact responsible for half of earth oxygen. There are signs that the ocean heat and lower pH is already causing great loss of these small critters. Earth has previously experienced periods of mass dying in oceans resulting in anoxic conditions and you get these special organisms that “breathe” H2S instead and you get very nasty conditions above sea level too (up to a certain height) making it hard for animals above oceans too.

      http://en.wikipedia.org/wiki/Anoxic_event

      But still said, the last big dieoff was said to have large effect in bottom dwelling creatures, while there has not been measured a similar response on land.

      Quote from wiki: “Current rates of ocean acidification have been compared with the greenhouse event at the Paleocene–Eocene boundary (about 55 million years ago) when surface ocean temperatures rose by 5–6 degrees Celsius. No catastrophe was seen in surface ecosystems, yet bottom-dwelling organisms in the deep ocean experienced a major extinction. The current acidification is on a path to reach levels higher than any seen in the last 65 million years, and the rate of increase is about ten times the rate that preceded the Paleocene–Eocene mass extinction. The current and projected acidification has been described as an almost unprecedented geological event.”

      http://en.wikipedia.org/wiki/Ocean_acidification

      The rate of change today is on a different order of magnitude so its clear that large changes can happen – although I feel McPhersons time schedule for it is a bit over the top. Its a bit like the ice sheets, all cards are in the air as we are really speeding up thing past anything our paleo-record has information air.

      Scientists are concerned, so we should be too – but the defeatism of McPherson takes us nowhere.


      • Btw, came across a recent article about this just now:

        http://phys.org/news/2014-06-modern-ocean-acidification-outpacing-ancient.html

        “Today, signs are already emerging that some marine life may be in trouble. In a recent study led by Nina Bednaršedk at the U.S. National Oceanic and Atmospheric Administration, more than half of the tiny planktic snails, or pteropods, that she and her team studied off the coast of Washington, Oregon and California showed badly dissolved shells. Ocean acidification has been linked to the widespread death of baby oysters off Washington and Oregon since 2005, and may also pose a threat to coral reefs, which are under additional pressure from pollution and warming ocean temperatures.”

  2. rayduray Says:

    Peter,

    This is a marvelous video. First rate! I hope it attracts a lot of attention.

    I particularly liked the clarity of Dr. Hansen’s discussion of the post-Ice Age Pulse #1 and the meter every 20 years warning. Yikes. Our civil engineering capacity in the U.S. is simply no match for such a devastating prospect.


  3. Look at the curve from 20k to 8k bp. That’s what real climate change looks like, not just mwp1a. The whole graph is a fast curve up during that time. Melting glaciers.

    • dumboldguy Says:

      It looks like the total rise from 20K to 14K BP was about 20 meters. 20 meters in 60 centuries is a little over a foot per century. Not much faster than the present rate of rise over the past century.

      During the 6K years of the pulse, sea level rose over 100 meters per, at a rate of 5 to 6 feet a century. Only the pulse portion of the graph is a really a “fast curve up”.


  4. […] Sinclair has a new video of the possible collapse of the West Antarctic Ice Sheet, or – more correctly I think – the early stages of a marine ice sheet instability. I […]


  5. Thanks for another terrific video. I do miss the snarkiness of crocks sometimes, but I think we have gone beyond mockery.


  6. […] of future melting and sea level rise is still largely unknown. Here’s a video and story from Climate Denial Crock of the Week: “…The research also provides the first solid evidence that the Antarctic Ice Sheet […]


  7. Well done! Thank you for the concise and clear explanation. And your choice of credible and informed sources.


  8. Thanks again for a great video.

    One quibble I always have with comparisons to melt water pulse 2b is that it happened at an early stage of deglaciation, hence there was an incredible amount of ice to melt as well then. So its pretty natural to deduce that the chances of a large melt pulse is greater than what we have left in Antarctica and Greenland. But then again the current CO2 forcing is so much bigger so its a different set of rules that current melt of these glaciers will run on. I seriously doubt we will see 1 meter sea level rise of every 20 years, unless we get into +6C average temps rise past 2100 and the ice sheets vanish at a staggering rate. It certainly looks though that this is the current path we are on with regards to the lack of CO2 emission cuts.


  9. […] 2014/06/02: PSinclair: New Video: Meltwater Pulse 2B […]


  10. […] Posted on 9 June 2014 by greenman3610 This is a re-post from Climate Crocks […]


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