NASA Satellite Measurements Show Unprecedented Greenland Ice Sheet Melt 411
NASA reports that measurements taken from orbiting satellites indicate the Greenland ice sheet underwent melting over a larger area than they've seen in 30 years of observations. On July 8, the satellites found evidence that about 40% of the ice sheet's surface had melted. Observations just four days later showed 97% of the surface had melted.
"This extreme melt event coincided with an unusually strong ridge of warm air, or a heat dome, over Greenland. The ridge was one of a series that has dominated Greenland's weather since the end of May. 'Each successive ridge has been stronger than the previous one,' said Mote. This latest heat dome started to move over Greenland on July 8, and then parked itself over the ice sheet about three days later. By July 16, it had begun to dissipate. Even the area around Summit Station in central Greenland, which at 2 miles above sea level is near the highest point of the ice sheet, showed signs of melting. Such pronounced melting at Summit and across the ice sheet has not occurred since 1889, according to ice cores analyzed by Kaitlin Keegan at Dartmouth College in Hanover, N.H. A National Oceanic and Atmospheric Administration weather station at Summit confirmed air temperatures hovered above or within a degree of freezing for several hours July 11-12."
Photos also surfaced last week showing the Petermann Glacier in Greenland 'calving' — some very large chunks of it broke off and started to drift away.
From the Article (Score:4, Interesting)
"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," says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data. "But if we continue to observe melting events like this in upcoming years, it will be worrisome."
Re:hottest in thirty years -must be global warming (Score:2, Interesting)
hasn't been seen for more than 140 years.
Stop and think about that for a moment. That means it happened previously, and nothing bad happened, we're all still here, and Florida isn't underwater yet.
Re:I'm not going to panic just yet... (Score:1, Interesting)
In addition, as you know if you have been paying attention, we have in fact had significant solar activity and some rather massive solar flares.
It is not at all surprising that we are experiencing a heatwave. And it just so happens to correspond to the normal 11-year cycle peak, so it is even doubly non-surprising.
It very much remains to be seen whether this weather constitutes "climate".
Got to look at the data as a whole (Score:5, Interesting)
Re:hottest in thirty years -must be global warming (Score:3, Interesting)
"... and this is the first time after 140 years, the summit has been observed to melt significantly."
Define "significantly". According to TFA, the summit was observed to be at or slightly above 0 degrees celsius for a few hours.
That's not enough to melt a decent snowbank in someone's yard "significantly". I doubt the summit had anything to worry about.
Greenland used to be... (Score:2, Interesting)
Greenland used to be farm land. It was called, "Green" land for a reason. But then about 600 years ago the planet cooled and Greenland farmers had to abandon their land. Harsh, and no, it wasn't because of humans causing climate change. Rather climate change has happened on a regular basis in cycles over the last several billion years. Now it is warming up and can be farms again.
The reality is that during periods of warming there was greater diversity. People need to stop focusing on climate change and focus instead on the real problems like toxic pollution and war. Global Warming is a just a distraction.
Unprecedented (Score:3, Interesting)
It's always interesting when an article provides precedence for something it labels unprecedented.
Re:Got to look at the data as a whole (Score:4, Interesting)
You're right. It's always an incoherent attack on a particular observation, data point, or (ad hominem) scientist, while ignoring the great bulk of the evidence. With all of the corporate money being thrown around to sow confusion and doubt amongst the public, you'd think that the fossil carbon industry would at least attempt to construct a defensible, competitive climate model that takes account of this body of evidence and produces the result they (and thus conservatives generally) want. But, of course they don't. PR may not be any cheaper, but at least they can be confident of the results.
If this is going to be a bona fide scientific controversy, then both sides have to be doing some compelling, quality science. So far only one side has.
Re:Atlantic Currents (Score:4, Interesting)
Not just in Europe. In 1776, Alexander Hamilton was able to drag the guns of Fort Ticonderoga across the frozen Hudson River to New York. By 1830, the ice on the Hudson was too thin for that, and by 1850 or so, it had completely stopped freezing over.
Re:I'm not going to panic just yet... (Score:3, Interesting)
The link you cite was a prediction from 2009.
A fact I mentioned myself in another comment. Your point is?
This graph of the last two solar cycles [wikipedia.org] shows that Solar Cycle 24 [wikipedia.org] is not nearly as strong as Cycle 23 (which peaked in 2000). So why didn't we have a similar or even greater melt off back in 2000?
Take a look at this graph from Wikipedia [wikimedia.org]. Notice that the latter half of the 20th Century has seen more sunspot activity (generally correlated with total solar irradiance) than the earlier 20th Century, or the latter half of the 19th.
If you put a pot of water on the burner of your stove, and turn the heat up to, say just hypothetically, medium-high, and let it sit there for a while, guess what happens? The pot will eventually begin to boil, because you are inputting more heat than it can dissipate otherwise.
If you then turn the heat down to, say, 5 (out of 10), guess what happens? It continues to boil. Because you are STILL putting in more heat than the pot of water can otherwise dissipate.
See, the exact up-and-down of the knob doesn't matter so much. The only thing necessary is that the heat input is greater than the heat dissipation.
We have no evidence that this is NOT the case with the Earth in the latter half of the 20th Century. The heat input (solar irradiance) was unprecedented, at least for recorded times. Yes, it has lessened... but who is to say that it has lessened enough to cause cooling to actually occur? We don't know because we haven't been recording that long.
Has solar activity been lower lately? Yes. But as the pot of water analogy shows, the temperature does not have to follow the actual curve of the input (one of AGW advocates' favorite -- but completely bogus -- arguments). It is sufficient that the input is over the minimal level that results in a net gain. Even if it's only 50% of what it was last year (an exaggeration, but the point is made).
Although the SHORT-TERM solar cycle has been milder than normal, we have been at the peak of longer-term cycles (called the "Solar Grand Maximum"), and that is going away now, or will be within a year or two. I expect most global warming predictions to start failing just about then.
Re:I'm not going to panic just yet... (Score:4, Interesting)
>"Troll"??? This is EXACTLY the same argument used by AGW proponents, when they are confronted with the fact that Country X had a colder-than-normal winter last year: "That's not climate, it's weather."
No it's not, the two arguments aren't even superficially similar though one is designed to try and look as if it is the other one - it's a bad make-up job that you fell for hook-line-and-sinker.
AGW proponents (in particular scientists) look at global averages, and the expected outcomes of that. They expect weather in some areas to change because of average warming in ways that may not be alike- including that global warming can CAUSE some places to have unusually cold weather.
Let me try and make this simple. If you have a clay fire oven, it's well known that there are "cold spots" in the oven where the movement of warm air actually creates convection holes that are significantly colder than the rest of the oven (any Pizza chef will have seen that for himself), in some cases those spots will actually be colder than the ambient room temperature (since the convection actually sucks the hot air from them) by a small degree (this is an extreme case for a pizza oven but on the scale of a planet it's not even slightly extreme but expected).
Now before you light the fire - the temperature is relatively uniform in the oven, no hot or cold spots. But as the fire warms up the cold spots form. The increase in the average temperature of the air in the oven actually CAUSES some parts to drop in temperature.
Yes, this is a terrible analogy and the real stuff we're talking about is massively more complex but the point of the analogy is merely this: most "colder than average" reports actually PROVES an increase in average warming. They are evidence that AGW is happening, not that it isn't.
Re:Atlantic Currents (Score:5, Interesting)
Well in the UK I think we're probably prepared. This last 7 years or so we've seen everything from massive increases in rain through to winters that have been about 20C below historical averages.
In each case it's been because the jetstream has moved out of it's normal position. In March we had drought conditions across most of the country, since then we've had record historical rainfall ever recorded for the month of July and so forth. In 2010 we had a January/February that was so bad we hadn't seen one like it for about 40 years, by November that year it happened again, so from once in 40 years, to twice in a year. Last winter was unusually mild, we barely even went below 0C which was in stark contrast to the -20C we'd seen the two winters previous. For reference, normal winters would see lows of -6C to -8C where I live.
Perhaps it's a natural cycle, perhaps it's because of man's actions, but either way the jetstream running over the UK has been acting quite differently to what we're used to since at least 2005. It could well be that effects on the gulfstream are already causing what you suggest.
On the upside, whilst the weather we've had with a lack of jetstream in it's normal position is not pleasant, it's certainly not going to be the end of civilisation at least - we've managed to cope the last few years, but it seems it means we don't get proper summers anymore.