Greenland ice sheet going, going…

Via ABC:

Melting of the Greenland ice sheet has hit a rate unmatched in the last 12,000 years and is accelerating, scientists have confirmed.

Research published in Nature today predicts that the Greenland ice sheet will be melting by as much as six times its current rate by the end of the century if we don’t get emissions down.

On the flipside, if we can achieve the best-case emissions reduction scenario forecast by the IPCC we can limit its increasing melt rate to around 40 per cent greater than its present rate.

As the earth emerged from the last Ice Age around 11,000 years ago, the Arctic experienced a warm period or thermal maximum between about 10,000 and 7,000 years before present.

Researchers presumed that the rate of melting of the Greenland ice sheet in that periodwas higher than it is today.

Instead, they found that over the last 20 years, the southwestern Greenland ice sheet where this research was focussed, has been losing ice at an rate of about 6,100 billion tonnes per century on average — around 100 billion tonnes more than at its previous historical peak, according to author Jason Briner from the University of Buffalo.

“Our results suggest that yes, this century we will experience ice-loss rates not just similar to those in the past but exceeding those of the past, even under strict carbon emissions scenarios,” Professor Briner said.

Worst-case scenario would see 600% increase in melting this century

As well as comparing present-day melting with the past, they looked at how different global greenhouse gas emissions trajectories would impact melting over the coming century.

They modelled the IPCC’s best-case emissions scenario, called Representative Concentration Pathway (RCP) 2.6, and the worst-case emissions scenario called RCP 8.5.

Under RCP 2.6, emissions are drastically reduced starting now and we achieve net-negative emissions this century. That is, we get our emissions to zero and also draw greenhouse gases from the atmosphere through technology or by boosting natural sinks like forests and blue carbon.

Under RCP 2.6 we limit global average warming to within 2 degrees Celsius by 2100.

On the other hand, under RCP 8.5 we continue burning fossil fuels as per usual, making no substantial efforts to reduce our greenhouse gas emissions through to 2100.

Under the RCP 2.6 scenario, their models forecast that melting of the southwestern Greenland ice sheet would increase to around 8,800 billion tonnes per century on average by 2100 — about a forty per cent increase on today’s rate.

But under the worst-case RCP 8.5 scenario, they forecast the southwestern Greenland ice sheet could be losing up to 35,900 billion tonnes per century — an increase of nearly 600 per cent on today’s melting rate.

Although their study area didn’t encompass the entire ice sheet, Professor Briner said Greenland tends to melt fairly uniformly.

“Based on reconstructions of ice sheet changes over the past several decades, it has been shown that when the ice sheet loses mass in our study area, it loses mass across its entire surface,” he said.

The study is an important demonstration of the difference that we can make by cutting emissions, according to David Etheridge from the CSIRO’s Climate Science Centre.

“The range of predictions shows a high sensitivity to emissions scenarios with the possibility to limit ice loss with low emissions,” Dr Etheridge said.

‘We still have time’ to slow down sea level rise

Modelling sea level rise was outside the bounds of this study, but the researchers tentatively suggest that the worst-case scenario melting from the southwestern Greenland ice sheet would add around 10 centimetres to sea levels this century.

If that was scaled to the entire ice sheet, that would likely be “doubled or tripled”, Professor Briner said. And that’s without accounting for any melting from the Antarctic ice sheet.

Research published earlier this month in Nature found that the Antarctic ice sheet will add 1.3 metres to sea level for every degree of warming up to 2 degrees Celsius above pre-industrial levels.

That research found that we have locked in at least two-and-a-half metres of sea level rise from Antarctica, regardless of what happens with our emissions from now on.

But it’s the rate at which the melting happens that we have some control over and is the crucial issue, according to Will Steffen from the ANU’s Climate Change Institute.

“We can still influence the rate at which Greenland melts and thus the rate that sea level rises. That’s the important message,” Professor Steffen said.

Rather than needing to adapt and shift coastal communities over decades, we can buy ourselves a century or more if we act to get emissions down immediately, Professor Steffen said.

When countries signed up to the Paris Agreement in 2015, the aim was to keep warming to 1.5C.

Given our lag in getting emissions down since then, Professor Steffen said he doesn’t think 1.5C is still realistically achievable, but keeping warming below 2C is.

Last week China — the world’s biggest polluter — committed to achieving net-zero emissions by 2060.

While he is cautiously optimistic, Professor Steffen said what is equally important is how they get there.

Currently China are responsible for about a quarter of the world’s greenhouse gas production, and if they begin rapidly cutting emissions from today right through until 2060, then that is significant, he said.

But if they continue burning fossil fuels and make rapid cuts at the last minute, the damage will already be done.

“We use what’s called the carbon budget approach to estimate how much temperature is going to rise — that is the cumulative emissions between now and net-zero [emissions],” Professor Steffen said.

“If [China] get their emissions down really quickly, say by 2040, that’s a big difference between whether they coast to 2050 and then cut them over a decade.”

But there is no warming. No virus, either. Mass immigration boosts decarbonisation. And Donald Trump is awesome.

David Llewellyn-Smith
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Comments

    • On the flipside, if we can achieve the best-case emissions reduction scenario forecast by the IPCC we can limit its increasing melt rate to around 40 per cent greater than its present rate

      The best we can do now is slow down the speed of the train that is going to hit us. That’s all that’s left.

  1. ErmingtonPlumbingMEMBER

    Im worried about what a 2.5 meter sea level rise is going to do to all my favorite surf breaks

  2. So, coronavirus which might kill a couple million elderly people is a crisis that warrants supra-national, autocratic takeover of the entire world

    But a climate disaster that threatens the extinction of the human race somehow still getting dealt with through market mechanisms and “democracy”?

    Absolutely incredible how stupid people are

    • “autocratic takeover” — we’re living in an autocracy now, like N Korea? Blimey, I must have been in a coma!

      But a climate disaster that threatens the extinction of the human race somehow still getting dealt with through market mechanisms and “democracy”?

      Which clearly has not worked. Luckily we are now in an autocracy so I’m sure our dictator will get it sorted.

      Absolutely incredible how stupid people are

      Pot, kettle.

    • Errrr, you know there’s a whole bunch of people who have been screaming for decades that market-based approaches to climate change can’t and won’t work, right ?

  3. PaperRooDogMEMBER

    “we have locked in at least two-and-a-half metres of sea level rise from Antarctica” boom times for cheap property around our coast and central capitol cities

    Go here
    https://coastalrisk.com.au/viewer
    and use manual option to see the effect of 2.5m (their default worst case is only 0.75m), maybe this is the real reason they are opening a new airport in Syd west as current one would be flooded,

    • ErmingtonPlumbingMEMBER

      Pitty how that manual slider only goes up to 10 meters.
      Still Narrabeen lakes looks awesome at 10 meters.
      Hawks Nest/Tea Gardens where I have family and friends is pretty much completely rooted at a 2.5 meter rise though.
      Sigh,…I hope they dont all want to move in.

    • The seas are already angry. I just was around Bundaberg and Byron and the coast is being smashed. More cyclones predicted this La Nina so I reckon if just one is bad, the realisation of the risk will focus most thinking people. All I see is downsides.

      • Mining BoganMEMBER

        Four Corners on Monday quoted a lady who said the beach is everything at Byron.

        Ruh Roh…

    • Link not working, But we’re not going to get there. Solar and wind are non-renewable-renewables – huge amounts of energy to manufacture, install, de-comission and dispose of, and with an EROEI (energy Retrun on Energy Invested) they’re a fraction that of FFs, and then there’s all the lithium, rare earth minerals, cobalt, palladium etc etc – both not enough, and hugely environmentally damaging to mine.

      It’s all a giant con. Garbagee tip Earth.

      • Too bad the idelogues continue to rail against the one low-emissions baseload power source that could actually make a difference in the here and now: nuclear.

        • Agree. Although we don’t have enough of even that 🙂

          Nothing for it but to downsize, which we won’t do voluntarily and so will have a population crash, as clearly food will become the deciding factor – or lack of it, with another 2 billion on its way and stuffed water and soils

  4. Ex - Communicado

    Was anyone really dumb enough to think the Greenland ice sheets would never melt? The only constant is change and that certainly applies to temperatures and ice levels. But sure you global warming alarmists and virus freaks trying to scare everyone to death are unassailable in your views! Sometimes you just need to take a xanax and chill dude!

    • desmodromicMEMBER

      It’s the rate not the fact that matters. Rapid change kills most biological entities because they can neither move nor adapt fast enough.

    • Peter PanMEMBER

      I went to one of the glaciers in New Zealand on a guided tour in the last year. Of course it is melting.
      The most insightful comment though was from one of the guides. Basically said that the glaciers formed during ice age periods and that simply put: to stop a glacier from melting, you need an ice age.
      So the melting of ice sheets and glaciers will not stop or reverse unless we have an ice age. So I guess we should wish for an ice age then????

      • TheLambKingMEMBER

        The most insightful comment though was from one of the guides. Basically said that the glaciers formed during ice age periods and that simply put: to stop a glacier from melting, you need an ice age.

        I am glad you are getting your scientific advice from a guy who could not finish high school rather than from scientists.

        Some of the glaciers are ablating (melting,) some were accumulating. But it is the rate of melting now that is the issue. At a pre-industrial rate those reducing glaciers would have taken 10’s of thousands of years. Now some will disappear in a generation or two.

  5. What a waste of time, humans can not control the climate anymore than they can control earthquakes, or volcanoes. It is delusional ! But anyway knock yourselves out being worried about that, when there are any number of real threats you can ignore, that will actually endanger and kill, people around the world, this year, next year, and every other year, before 1 person dies of being slightly cooler or warmer, in bathurst or perth at the end of the century.

    • Let me guess.. your workplace is here? 55 Savushkina Street, Primorskiy district, St. Peterburg

    • RobotSenseiMEMBER

      It’s those meteorites smashing into the Yucatan that are the real threat, right? 65m years. We are overdue.

    • We’ve virtually dammed every river, highly modified all the arable land, wiped out 30 mammals in Australia alone in 200 years as part of a broader mass extinction event, factory trawled significant portions of the oceans, which are riddled with plastic, but the atmosphere is pristine?

    • agree TREx. Its a way for people to virtue signal and feel good about themselves when they know they are bad. People on this forum talk good, but never stop using their cars or stop buying products wrapped in plastic (milk) etc. As stated, moaning on here is a way to absolve their sins, nothing else.

  6. Display NameMEMBER

    Spent a week or so in Ilulissat, Greenland last year. Stunning scenery in Disko bay.

    Had a trip almost 40K north, up the coast in a 4m boat with twin outboards to see one of the big glaciers. There were 5 passengers on the boat with a small cabin. All was good until we got within 5-6km of the glacier when the boat had to initially slow down to about 6 knots, and started hit small pieces of ice. The wife of one of the other passengers starting getting a bit antsy, asking the driver if he had done this before. By the time we were 2k from the glacier the boat had to more or less cut thru the ice. She was a nervous wreck until we got back to open water. It was a little tense, the hits on the boat from the ice were bloody loud. The view of just spectacular. Saw a few small calves while we were there, rocking the boat significantly.

    At the glacier face, a couple of guys (greenlanders) were seal hunting in an even smaller boat. One of the guys in the boat made a shot over 50m and hit a seal on a berg from the bobbing boat. Unbelievable shot.

  7. A triple boat garage, luxurious completely sealed submerged frontage with fatastic underwater views, 2 balconies that completely seal at high tide, and a DA for a small submarine port. There $4.2 million right there!

    $4.2 million going once, going twice, going… interruption. Of course there would be, this is Australia.

    Sad long face days a head for ya’ Ruesa, Aquaman and the Marine Girls will be the new sexy. You’ll be a part of the terrestrial has beens, getting drunk on clean skin pinot griggio, reminiscing the good old days, you’re getting climate changed.

  8. You have to admire their accuracy 100M tons lol

    Anyway, they always fail to note that sea rise has been pretty much linear since the end of little ice age ( mid 19th), no correlation with CO2

  9. Well 12k years ago we were in an ice age, and I doubt it is melting as quickly as 7k years ago, at the interglacial peak, when temps were 1.5-2 degrees warmer than now!

    • Humanity has now raised global CO2 levels by more than the rise from roughly 180 to 260 ppm at the end of the last ice age, albeit in a few hundred years rather than over more than a few thousand years. “The end of an ice age, you have a sense in your bones what that means: a big, significant change for the planet,” Shakun says. “It’s a tangible example of what rising CO2 can mean for the planet over the long-term.”

      In fact, the amount of global warming already guaranteed by existing concentrations of CO2 in the atmosphere—392 ppm and still rising—will also play out over centuries, if not millennia. “The rise at the end of the Ice Age and today is about the same [a rise of 100 ppm] and we’re going to be well above and beyond,” most likely increasing concentrations of greenhouse gases by hundreds of parts per million from preindustrial levels, Shakun notes. “We will only see some of that realized in this next century. It will be many centuries and beyond to feel the full effects.”
      https://www.scientificamerican.com/article/what-thawed-the-last-ice-age/

  10. Good news everybody, relax, its all good – the earth is drifting away from that evil body that is melting all the ice – yes the SUN
    https://www.forbes.com/sites/startswithabang/2019/01/03/earth-is-drifting-away-from-the-sun-and-so-are-all-the-planets/
    oh, but does it matter if the SUN gets hotter or colder? I suppose there is SUN flares too… This climate change modeling seems so complicated…. I better leave it to the experts that are always right e.g. “TIME Magazine Archive Article — Another Ice Age? — Jun. 24, 1974” and how the ozone hole was fixed by removing CFCs https://www.cbsnews.com/news/arctic-ozone-hole-largest-closed/
    I mean seriously how do you expect anybody with half a brain to fall for climate alarmism AGAIN?