It's not as if the melt water is going to go anywhere before the stuff re-freezes
Repeated ridges of warm air passing over Greenland since May have induced what NASA says is the largest surface melt in the mostly-frozen island in the age of satellite observations. The once-in-150-years surface melt – which will, it’s important to note, still leave most of the huge 3.2 km centre ice sheet in place – took …
snow is well known for not running down gentle slopes but to the best of my knowledge water does it PDQ.
And when the water gets under the snow it makes it move downhill too.
This has only just happened so it might be a little while before its effects (if any) are felt at the coast - and then reported - but dismissing it out of hand is a bit desperate.
The only thing that's important is how often this has happened in the past, and, if it has, is the frequency or intensity increasing. AFAIK there's nothing in the report that would indicate that it's abnormal. What's interesting is that there appears to be yet another cyclic pattern in the climate.
So alarmists and deniers can sit back down because it does nothing for either of your causes :-)
El Reg quote:
"JPL isn’t attributing this event to climate change, but rather to a predictable cycle in Greenland’s weather. "Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time," said Lora Koenig, a glaciologist at NASA’s Goddard Space Flight Center."
"He said that, because this Greenland-wide melting has happened before, Nasa is not yet able to determine whether this is a natural but rare event, or if it has been sparked by man-made global warming.
Scientists said they believed that much of Greenland's ice was already freezing again.
Until now, the most extensive melting seen by satellites in the past three decades was about 55% of the area.
Ice last melted at Summit station in 1889, ice core records show.
The news comes just days after Nasa satellite imagery revealed that a massive iceberg, twice the size of Manhattan, had broken off a glacier in Greenland."
Which comes across as balanced, and which comes across as "OMGOMGWe'reallgoingtodie!!"?
Pretty sure I'm going to get flamed for this, so...
I also saw this elsewhere and it had the standard doom-laden 'since records began' but it seems it's not the first time and it also appears that there is something like a 150 year cycle.
I'm finding it both interesting and frustrating reminding people that we haven't a clue how most weather cycles interact and also that we are in the 'Deep Thought' stage of computer predictions as we don't even know how the smaller cycles affect each other, let alone ones that appear to be 150 years.
I love "since records began" trivia. my favourite was the whale in the Thames near central London - the first seen since records began in 1913. Who in 1913 thought they would keep a log of not seeing whales in the Thames? Was it an easy job until 1996, with entries such as "no whales seen today" or "abandoned car tyre caused false alarm" etc. etc.
Anyhow - back to the topic in hand....
The register quote is slightly wrong.
JPL aren't attributing the event to "a predictable cycle in Greenland’s weather". JPL aren't attributing it at all. It could be natural, or it could be a result of man-made global warming. Which is in line with the the other scientist the BBC quoted:
"He said that, because this Greenland-wide melting has happened before, Nasa is not yet able to determine whether this is a natural but rare event, or if it has been sparked by man-made global warming."
The last part of what Lora Koenig said, which the register paraphrased, is key:
"But if we continue to observe melting events like this in upcoming years, it will be worrisome."
As an aside the scientist said an event like this happens once every 150 years on average. That doesn't mean it's a cycle or predictable anymore than a 1/6 chance of rolling a 6 on a dice means 6s come in predictable cycles. Cycles are periodic not random.
Won't stop The Church of Climatology punting the image around saying/inferring/implying/spinning 'Man-Made Melt Apocalypse' all the same, you watch.
Then of course, subsequently, the downvoters will defend that behaviour, or unable to construct a defence, just be offensive about anyone saying they'll do that.
Actually you can't say it isn't man-made. It might be.
What they've said is that a single event could be natural, but lets wait and see if it happens again in coming years. Out of interest what will your excuse be if the same level, or more, melt occurs next year?
We are seeing an acceleration of mass loss in greenland and a sharp decline in sea ice. We are just about reaching points where it's unprecedented in great lengths of time.
It's a pretty disingenuous approach to colouring they've chosen for the map. With the white ice sheet apparently disappearing it certainly looks as if they're trying to give the impression the whole thing has melted to anyone who doesn't RTFA. Or even if you do read the article in the case of the one the BBC wrote.
And despite their statements, if it happens again next year, or any or each of the next five years, it shouldn't be surprising either. It's only if it continues unabated that it is a surprise, and even then we do have to remember that once upon a time, Greenland was actually not frozen. It just happens to have been for the last couple hundred years, which is but the blink of an eye on a geological time scale.
The Greenland ice sheet is a bit older than 200 years - try 110000 years*. Still a blink of an eye in geological time scales, adminttedly...
And if this level of melting, which is currently unprecedented in the last 30ish years of satellite observations, and 150ish years of surface station observations, happens again next year *or* continues for 5 consecutive years it will *definitely* be surprising.
[*: Meese, DA, AJ Gow, RB Alley, GA Zielinski, PM Grootes, M Ram, KC Taylor, PA Mayewski, JF Bolzan (1997) The Greenland Ice Sheet Project 2 depth-age scale: Methods and results. Journal of Geophysical Research. C. Oceans. 102(C12):26,411-26,423.]
So melting that took place over a few days which probably only melted the top few millimetres or centimetres of the ice sheet is now seen as a total disaster and the end of the world is nigh. What none of the reports say is that the ice will probably be back to normal levels as it refreezes. Some water will have washed away but the vast majority of it will not have had a chance to get to the ocean.
The top of the Greenland icecap is so high that it's very rare to get a thaw at such high altitude, and in this case it only lasted a few days. This will bring quite a flood downhill and through holes in the ice to lower levels though, even if the total water volume melted is very small compared to that held in the entire cap.
What is of much more interest is the extent to which warming at sea level destabilises the bases of glaciers and the extent to which this allows them to flow downhill faster. I think we'll know much more about this in 10 - 20 years time than we know now.
According to the scientists, this sort of thing happens 'on average' about every 150 years. Not sure what the standard deviation is on that, which would have been good for them to quote as well. Might be pretty damned regular, or all over the place, but averaging 150 years. Given the last one is in 1889 and the difference to today is 123 years, there's obvious a reasonable degree of variation at least.
is it important at the moment......no. It's a bit more data, nothing more. if we get it every year from now on, that's interesting. However, whether it's significant also depends on how far back their 150 years average data goes.
Bearing in mind the unusual weather we've been having recently and that being attributed to the jetstream being further south than usual, are we really surprised? A large chunk of the northern hemisphere seems to be having odd weather this year, so getting an unusual position of the jetstream is more than likely going to cause other effects, maybe even ice melt in Greenland!! Maybe they're unconnecetd. Who knows, but one thing changing normally changes other things.
So, why are we surprised?
I also found the colouration to be highly misleading. If you are a bit 'challenged' and looked at the pictures, you might think the ice cap on Greenland had melted completely!! Using white to represent 'no melt' seems a rather odd choice if the research is meant to be unbiased as it definitely gives an 'impression'.
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