By Mark Halper
Posting in Energy
Staggering satellite photos from NASA reveal that nearly all of the top layer vanished from July 8 through 12. Blame fossil fuels? One NASA boss advocates nuclear power to stop global warming.
Almost all of Greenland's surface ice melted in a 4-day period earlier this month, NASA satellite photos reveal.
From July 8-12, 97 percent of the top ice melted. Normally, Greenland loses about 50 percent of the layer over the course of a summer, much of which quickly refreezes.
A NASA press release notes,
For several days this month, Greenland's surface ice cover melted over a larger area than at any time in more than 30 years of satellite observations. Nearly the entire ice cover of Greenland, from its thin, low-lying coastal edges to its two-mile-thick center, experienced some degree of melting at its surface...On average in the summer, about half of the surface of Greenland's ice sheet naturally melts...But this year the extent of ice melting at or near the surface jumped dramatically. According to satellite data, an estimated 97 percent of the ice sheet surface thawed at some point in mid-July.
To illustrate the extent of the melt, NASA observed that even at 2 miles above sea level - the sheet's highest elevation - ice "showed signs of melting."
NASA released the photos a week after reporting that a Manhattan-sized chunk of glacier broke off from the N. Atlantic country and morphed into an iceberg.
This summer's melt is the most pronounced in Greenland since 1889, Kaitlin Keegan from Dartmouth College notes in the press release.
So, is man made global warming the culprit? NASA glaciologist Lora Koenig notes that Greenland experiences such melting events, "About once every 150 years on average. With the last one happening in 1889, this event is right on time. But if we continue to observe melting events like this in upcoming years, it will be worrisome."
As SmartPlanet reported earlier this week, NASA Goddard Institute for Space Studies director James Hansen - a staunch campaigner against man made global warming - is encouraging President Obama to back nuclear power as a C02-free, and thus eco-friendly form, of energy.
Hansen co-signed a letter that British billionaire Richard Branson sent to Obama pushing for support in commercializing an alternative nuclear technology called an Integral Fast Reactor, which he says is better and safer than today's conventional reactors. Eric Loewen, the president of the American Nuclear Society and also the chief engineer for General Electric-Hitachi's PRISM IFR, also penned the request.
This week's NASA press release says the Greenland melt has "coincided with an unusually strong ridge of warm air, or a heat dome, over Greenland," that was the latest in a series of ridges since the end of May.
That sounds to me as though it coincides with the jet stream meanderings that have wreaked havoc on weather elsewhere in the Northern Hemisphere this summer. Question: did CO2 emitting fossil fuels push around the jet stream, or did it move of its own natural accord?
Photos: Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory
More weather and atmospheric observations and solutions on SmartPlanet:
- Virgin Nuclear? Branson asks Obama for reactor help. Sir Richard v Bill Gates?
- Harnessing the jet stream for wind turbines
- The Sun: Up close and personal
- CO2 not warming planet as much as thought
- Remember ozone holes? NASA just found a big one
Jul 24, 2012
The problem is not the oft-repeated sea-level rise or slightly warmer temperatures, which will take decades. The problem is the Northern icecap has a great effect on global weather patterns, the jet stream, and ocean currents. As this melt quickens, the weather will become erratic for a few years. The problem with that is, agriculture depends on reasonablyï»¿ stable weather, and the planet has almost no food reserves. So the true effect is not flooding, but mass starvation. Rush Pigbaugh and his lying corporate-led ilk have condemned millions to hunger, because it is now too late.
Global warming causing climate change by man means there is a source of atmospheric heat. Weather is basically the interaction of cold and warm air with water vapor, we need to stop the heat. In order to stop the heat, we need to see it and can't so C02 was blamed. Here is what we missed in the calculator. Building development and there energy consumption are designed for specific climatic data for that region. In Canada climatic data is provided for building code by Environment Canada. At the end of the day buildings are signed off as compliant with building code without verification, we couldn't see it even with building code telling us to watch out for solar radiation. Here is what we missed in the calculator on solar interaction and we are responding to the symptoms with massive energy waste. Nuclear energy won't address the problem, it is reacting to symptoms. http://www.thermoguy.com/blog/index.php?itemid=88 Here are 2 infrared time-lapsed videos showing buildings being radiated in the morning and how people are literally cooked by their buildings during heatwaves. http://youtu.be/EA3py3us5VM Stop the heat generation, it is a big economy. Once you generate this heat, it can't be destroyed and it circulates the world changing weather.
If you go back to the original NASA article, and look at the map, there is a legend that is missing from the one re-pubublished in this article. The colors are labeled: "No data" (very small) , "Ice/Snow Free" (small area), "Probable Melt", "Melt", and "No Melting". That makes it pretty clear what is going on. I don't know why this critical bit of information was left out. I can speculate, but I just don't know. I've found that many of these articles about other articles over-simplify what the original described. Before going super-critical and hitting down straw men, it is wise to go back to the original sources. .. and to the authors: put the legend back on.
If it is global warming that caused this very predictable and cyclic event, what caused the one in 1889, and the one 150 years before that, and the one before that. This panic is just another sign that climatologists don't have a clue when they address issues like this. They need to look at the hard science that has studied this type of phenomena for decades. When you want to know about what happens to glaciers ask a glaciologist. There is no mystery here.
Scientists have no evidence that global warming, if it is occuring at all, is man-made. Using the term "man-made global warming" is blatantly dishonest and compromises scientific objectivity.
1) How can this be "unprecedented" and at the same time a cyclical event: "melting events of this type occur about once every 150 years on average"? And how about the text indicating similar melting was observed just 30 years ago? That's not every 150 years if the most recent cyclical event was "in 1889". The text of the article makes it clear it's not at all believed to be unprecedented. So why does the headline say it is? This is in the NASA web site, so I assume it's NASA that wrote the erroneous and misleading headline.... Why did they? Just based on this it's clear: It's not unprecedented, but in fact appears to happen at least once every 150 years or so, on average. Sometimes it occurred outside the 150 year cyclical period (which explains, the "on average" qualifier, I guess.) NASA intentionally misrepresents the report in its headline on its web site. 2) This is based on satellite measurements. Measurements of what? I doubt we have satellites with 'Ice detectors'. So what is being measures, and used as a proxy to extrapolate ice melting? How accurate or reliable is this as a proxy for melting? How has that been measured or verified? Was this simply measured near-surface temperatures, as the article seems to imply? Can we simply assume these measurements mean the ice surface has melted? That assumption seems implicit here, although it's not clear how it was confirmed, nor that it's a given. 3) The closing statement endorses a NASA initiative, in the classic "we're getting a return on our expenditures here (so keep them coming)" NASA sales format. But this is a bit too suggestive. "Nghiem's finding while analyzing Oceansat-2 data was the kind of benefit that NASA and ISRO had hoped to stimulate" also suggests directed research, commissioned to obtain specific results. And as we all know, if you pay for particular results, you can be pretty sure you're going to get exactly the results you want, one way or another. Perhaps this merely means "meaningful results" in general, but it's not too much of stretch at all to assume it suggests, rightly or wrongly, "results that support the conclusions we want". That would be horrid, but even the appearance of research jobbing is bad enough. All-in-all it seems a useful, but unremarkable, report, with some methodological uncertainty that should be addressed (and could be I'm sure). But NASA chooses, for political and institutional reasons I'm sure, as well as ideological ones perhaps, to misrepresent the findings, their meaning, and the implications. Once again NASA very clearly has diverged from scientific objectivity and intellectual rigor, and apparently for the same reasons it always has, since its founding: self justification and appropriations.
I really wonder if NASA released this photographic data touting it as actual loss of ice pack? If they did, clearly the scientific community of NASA has been corrupted. They need to lay off the old science stuff and get back to the redirecting of their charter to actively reach-out to the Muslim community to make them part of the space community.
For data on human impacts -- or lack of them -- check out http://www.worldometers.info/. It may surprise you -- or not.
I am not a scientist but I do know that there are people with an agenda that wants us to accept that global warming is real and is created mostly because of us. I know respected scientists disagree on if there is global warming AND disagree even more on whether it is because of human beings. But there is a dilemma here. What does a scientist recommend to a government and to people in general if he believes that by the time definitive proof of human-caused global warming exists beyond reasonable doubt it will be too late to stop or reverse it?
Knowing little about meteorology, except that I do not like it when it is over 100 degrees, I hope that this melting trend can be observed and if it is found to be man-caused rather than a natural cycle as it seems to be now, that it can be corrected. A big deal is made about personal vehicles polluting and the number of vehicles in the United States with large-ish engines that do consume more, always a popular target for screaming environmentalists. But it is nothing compared to the pollution caused by the airlines of the world. Unfortunately, when it comes to discusssion about reducing human-made pollution, such facts are skipped over and personal cars and thermostat settings are frequently discussed, with much ashes and sack cloth. It's misdirected. Aircraft are never discussed but they should be #1 on the list of air polluters. [b]"On a New York-to-Denver flight, a commercial jet would generate 840 to 1,660 pounds of carbon dioxide per passenger. That's about what an SUV generates in a month."[/b] -USAToday, DEC 19, 2005 (not that USAToday knows squat, but they probably did get the data somewhere reputable such as Scripps Institute of Oceanography, and the Pacific Northwest National Laboratory's Research Institute at University of Maryland) It's no so much the cars. Let's use the high number for everything;; Consider a SUV is typically under-utilized and has one person. That is 1660 LBs a month. The usual jet has 150 people, each making 1660 lbs of pollution per day. (Or pick a jet plane size you like) Anyway that is 4,980,000 lbs pollution a month, assuming 20 weekdays when it is full or flying per month. 1.) Each person flying is responsible for 1660 lbs of pollution per weekday. 2.) Each prson driving a gas guzzling SUV is responsible for 83 lbs of pollution per weekday So, in fact, I am not interested in having my car conveniently blamed and my costs inconveniently increased because of something others do. Pollution will never drop until the aircraft pollution is addressed. Please do not say a single word about drivers in the US with big cars until Globally the air travel related pollution has been addressed. The fact is that people who can afford to fly do it all the time, and pollute disporportionately, and the blame is directed to personal car ownership. I have no objection to people flying, but I object to that CO2 being blamed on cars. Air travel has become too commonplace, when it should be reserved for only the most important necessities and emergencies. It happened because the developed world became affluent enough to pay for it, and back then no one thought pollution was much of a concern. Now air travel is an ingrained habit and we have to face down this major pollution source. There are alternatives to flying, like: Telepresence (computer-based, video, and voice conferences) for business meetings. It is of course important to establish face time with customers, but if it is not hands-on such as engineering, then after the physical meeting, subsequent meetings can be electronic. Road trip. - Yes, you can drive from Houston to Oklahoma City to visit a customer. Go up the day before, get rooms.. With today's modern communications systems it is possible to work 'on the go', especially if there is more than one person. One can drive and the other work, then switch. Cars are much more comfortable than crappy aircraft seats, and think of the airport hassles and body cavity searches avoided. Driving or even taking the highway bus (which is not so great) is the way long distance face to face work was done in older times when flying was an expensive luxury. These ideas presume you can spend a day traveling, but let me throw this out there. Isn't reducing the obscene amount of pollution caused by aircraft worth a little inconvenience? After the terrorist attack of 2001, air traffic was much reduced over the USA and other locations for many days. During this time, the air over certain locations cleared up substantially. I think it was a chemical change that was detected by optical instruments that brought it up. I can't find the reference to this right now but the data is on the internet. This ought to prove the thing is a serious concern. The level of air traffic is not sustainable. The above is an opinion.
I think the headline was very misleading. To most people, 'surface ice' means ice that is on the surface of the ground - not the surface of a bit more ice. Also, we are presented with a picture of Greenland before and after, with the after picture showing no white, which immediately suggest no ice at all. Scare journalism indeed. Surface 'ice' is a misnomer as well. The stuff that is on the surface is snow, not ice. It does not compact to ice until the snow/firn/ice is about 100 metres thick. So, how can one talk about the surface 'ice' melting without meaning ALL of the ice.. This article was not written to inform; it was written to annoy. It certainly worked!
I'm not a global warming / climate change denier, but I have to say that the graphic seems designed to make people think that all of the ice in Greenland melted over a few days. The text makes it clear that this didn't happen, but that a lot more than the usual melt occurred. The text also makes it clear that this was an expected event (once every 150 years). But that graphic, while properly illustrating the event, doesn't have enough text in the caption to explain it and makes it look like a disaster must have occurred.
Again a seen phenomina is taken as a stand alone reason for action. Is there any expert out there that are taking a holistic approach to climate change. The Earth came out of an ice age 11 thousand years ago and has not yet settled. There is a rise in methane hydrate melt is this calculated. The moon moves away from the Earth one centimetre a year, and thats not counting what is happening on the sun. There are going to be problems for costal Cities as the sea levels rise it is stated. Why then are there no plans for large scale water based Cities with power control systems.
What a lot of bullshit.The Planets mean temperature is 3.9 and rising.We can expect worse too come.Pretending it happen before,will not change a dam thing.
If you go to the NASA source article at the link you will find that the figure only shows that the [b]surface[/b] of the ice melted. Nowhere does it suggest that all of this year's ice melted. From the article: [i]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.[/i] In other words, for two days, for several hours, air temperature was very close to 32 degrees F. This created "pronounced melting". Scary tales of Global Warming
He has long since passed out of the realm of science into the realm of psuedoscience and activism. His ridiculous comments about the 'unprecedented' Texas drought are a classic example of how poor his science skills are. Do I really have to point out that a 30 year record is hardly conclusive? Especially, as others have pointed out, since we know there were times in the past when the climate was warmer in Greenland.
Greenland's surface ice layer melts every summer. Trying to stop this is like saying we want to stop summer. Just another example of people with activist agenda's cherry picking data to fit their agenda. (Although, I do think we need more nuclear energy not less.)
says WHO? You say this like it is true but checking your source it seems all of the Fox News team isn't completely convinced..there is some doubt. SO you should watch more Fox and strengthen your brainwashing and your mistaken opinion.
You're the one being dishonest by saying actual scientists have no idea and no evidence about global warming or about what is causing it. Greenhouse gases are pushing up the temperatures, that's the agreed and evidenced consensus among scientists. Don't preach about scientific objectivity when you have _no idea what you're talking about._ The only thing that fits the models of what could be warming the Earth this way and speed IS an increased level of greenhouse gases, specifically CO2 from fossil fuels. What's not known yet is exactly how fast and how severe the effects of global warming will be. But we can assume the effects will not be nice nor cheap to deal with, especially the longer we wait to acknowledge the problem is real and must be dealt with. The simple-minded _deniers will always be a part of the problem_ and not a part of the solution.
Of course we have satellite ice detectors. They also detect open water, forests, mountains, praries, etc. There are satellites that us radar to measure changes in elevation of the surface. The GRACE satellites detect changes in gravity that show ice loss on Greenland. The 30 years ago referred to in the story was when the satellites went up, not the timing of a melt event. The 150 year average is misleading because the time between the 1889 event and the one before it was 700 years. Here's a link to a graph of the events for the last 10,000 years at one ice core site: http://www.gisp2.sr.unh.edu/DATA/alley1.html
I have said all along the people of the world need to be more concerned about REAL pollution than CO2 and global warming. Long before the seas would rise from any kind of global warming, manmade or natural cycle, the people of the world will be suffering greatly from the increased amounts of lead, mercury and a host of other proven toxins that are being dumped into the air and water every day by the largely unregulated power plants and factories in countries like China, India, Brazil and others. China alone has become an ecological nightmare over the last 30 years with the out of control pollution. US pollution at its worst in the mid to late 20th century, when the river in my home town looked like a rainbow and several urban rivers actually caught fire, was never as bad or on the scale of what China is facing now. Focus on the proven problems. The unchallenged issues. Nobody will deny smog and its component toxins are a problem. Nobody can deny dumping toxins is bad. The hard science is there and decades old. If we can develop Affordable renewable energy sources they will cut down on PROVEN pollution. Affordable renewable energy sources will reduce our dependence on foreign oil and if done right, could even SAVE the average consumer money as the price of oil goes up. Saving the average energy consumer money on basic needs is beneficial to an improved standard of living across the planet. Solutions for renewable energy are pointless if the cost of them push the worlds people deeper into poverty as a few get richer. If you wish, consider the additional CO2 reductions a beneficial side effect of the bigger effort.
The whole air travel and air freight sector contributes about 3% of the total human CO2 emissions, not insignificant but also not #1 on the hit parade either.
I totally agree with you on the air travel. As with any other goods & services, the industry strive to maximize profits, compete to get more revenues. So as airlines need to make more money, buy more airplanes, get more people to fly by making it more affordable, then low-cost/budget airlines pop up to soak up more customers....the snowball effect just keep adding on. Same with the shipping industry, more & more ships in the seas - cruising for pleasure as well as cargo ships. We just keep adding more stuff, thinking that the earth is so huge it can & will forever absorb all the pollution we create. All businesses only want to make profits. Far too few bother to include the cost of environment in that profit.
Media figures flying coast-to-cost in private jets to give lectures on the evils of CO2 are our biggest threat. Arianna Huffington is responsible for more CO2 in a week than my SUV has been over its entire existence.
The average over the Holocene has been every 150 years but there was a 700 year gap between the 1889 event and the one prior to it. From 4,000 to 8,000 years ago these melt events were much more common. Here's a graph of the events for the past 10,000 years: http://www.gisp2.sr.unh.edu/DATA/alley1.html The green lines are the melt years. As you can see the July insolation was much higher in the early Holocene (because of a different state of the Milankovitch Cycles).
The fact that YOU only see THIS data does NOT mean that scientists will be making determinations on ONLY the data YOU see. Scientists spend their LIVES studying the science. YOU come just in this moment, and complain about THEIR "lack of perspective. Such behavior does not flatter your intelligence. ALL of the effects you cite above operate at vastly greater time-scales than we see in the current temperature rise. If CO2 IS linked to temperature, then the danger could not be more clearly drawn. The UNPRECEDENTED current rise of that gas in the atmosphere is the steepest slope that has EVER been seen on the planet. That alone should make the hair on your neck stand up, wondering what is coming next.
This planet is a living organism in and of itself. Were it not for "global warming" we would not exist and this planet could still be in an ice age. The planet warmed up with no help from us before Humans even existed. To say we can help slow down effects of a natural planetary occurrence is one thing == to say that humans are the only thing that can stop it and "cure" the world is egotistical. We as a species have learned to adapt to many climates on this planet from the Arctic Circle to the equator. When did we start assuming that everything must now adapt to US?
As stated in the article above So, is man made global warming the culprit? NASA glaciologist Lora Koenig notes that Greenland experiences such melting events, âAbout once every 150 years on average. With the last one happening in 1889, this event is right on time. But if we continue to observe melting events like this in upcoming years, it will be worrisome.â If anything, this is evidence against global warming, and pointing more towards a natural shift. That being said, I actually like a lot of what the proponents of global warming recommend to try to mitigate the effects, not because I believe that the global warming trend is man made, but because following most of these suggestions would wind up cutting our dependance on non-renewable energy, especially foreign oil. This can only help the U.S. in the long run.
Hello LivermoreEngineer - You're absolutely correct, but I'm not quite sure why you're pointing this out. If it's to reaffirm my story, thanks! If you're suggesting that I reported that all of the ice melted, then please be aware that my story states "surface ice" throughout, starting with the headline... Here's a thought to skate with: As long as these glaciers are pouring forth, why not tap them for hydropower? That's what Iceland does. They have, arguably, about 150 years left of glacier power. That's one reason they're upping the geothermal quotient. Iceland today: 100% "clean" electricity - 75% hydro, 25% geo, soon to increase. Taking this thought to a more global scale: Run subsea high voltage lines from the N. Atlantic countries to ply Europe and N. America with "green" power.
It's an 'Administrative' agency. It doesn't 'do' things, it administers their being done. NASA administrators aren't active scientists, doing science. They are administrators (i.e. managers, bureaucrats, paper-pushers...) managing 'science projects'. As such their role, within a government bureaucracy, is self-justification, marketing and generation of 'causes' for appropriations. This was Mr. Hansen's role at NASA, among the most highly politicized and marketing driven agencies of all time. Why on Earth should we expect scientific objectivity from NASA or it's administrators, past and present? I think it like expecting 'the tiger to change its spots'.
@ randall wilkinson : It said this much melting happens only once every 150 years on average, and it was due to happen - nothing to worry about unless it happens repeatedly. They're not cherry-picking anything, you're just assuming an agenda where there is none. No conclusions were made about global warming at all.
Perhaps it's more apparent this year as the JetStream across the Atlantic moved South this year and dump lots of rain on the British Isles and Northern Europe.
No counter points, no data for discussion. Just name calling and insults. Your programming says to hit the repeat button and post again.
It is unfortunate that the developing nations followed the same path that the US did in the last 100 years. This is the only habitable planet we have within our reach and we are making it uninhabitable by over fishing, over producing resources and cavelierly wasting those resources. The problem behind this problem is the extra burden on planetary resources by an ever increasing human population. We are the ultimate invasive species with nothing to keep our population in balance.
I also read the same comment in the NASA article. But just how does NASA know when these warming spells occur? We had accurate thermometers in 1889, but not 150 years before that. We might have been measuring the ice in Greenland in 1889, but I doubt ice sheet research was being done on Greenland before. So how does NASA come up with this "every 150 years or so" figure? Just what characteristics of the ice core sample do they use when the ice itself from these times may not be present? Many people think the age of the ice is measured by counting the layers. The problem is that after a few hundred years the layers disappear because of compression. At that point the electric conductivity of the ice over different lengths is used to measure how old the ice is. The problem is that the correlation between electric conductivity and age is just another computer model that is hard to verify against real ice cores. There are a few places where they can match dust in the ice cores with dust from known volcanic eruptions, but our historic records of volcanic eruptions only go back about 3000 years. Beyond that, it's all guesswork.
To many unsophisticated readers, "surface" ice will mean the ice that overlays Greenland's rocks, ie. ALL of the ice. Indeed, I am reasonable science-literate, but that is how I took the intended message of the link text at first. It sounded to me as if you were saying that ALL of Greenland's ice had melted. I knew that was sheer nonsense, but I was also unfamiliar with the dichotomy (in science?) between "surface" ice (what does that MEAN?) and the "rest of" the ice. Perhaps your FIRST paragraph, on a pop-sci site, should have been a definition of that term. Perhaps there is still a need for such. The graphic did not help, either, as the white part of it was completely gone, lending to an interpretation that the ice had also completely gone. It is mistakes like this, that let the ignorant think we are trying to scare them to death. Science is more than presenting conclusions or research. It is presenting them accessibly; which for the science illiterate, this does not do.
I live in Texas, when the surface ice melts, there's no more ice. You used a vague term that the vast majority of people's understanding is quite different from your usage. Put the indignation away, it sounds more like you're whining. So, please clearly define the term - surface ice - using objective measures that most people can relate to.
ManenAhADah greatly mistates NASA's role today and what it does. Much less who staffs it and who runs it. His/her assessment of NASA is as wrongheaded as the use of old saying to sum up the argument. Tigers don't have spots, and you completely mistated it. I suggest you do a little more investigation into NASA as opposed to showing your complete ignorance of NASA and it's mission.
Since the Obama administration killed manned space exploration NASA has a new mission. Quote - The White House will direct NASA to concentrate on Earth-science projects â principally, researching and monitoring climate change. - http://blog.heritage.org/2010/01/27/obama-is-no-kennedy-redefines-nasas-mission-as-global-warming/
did they have polluting industry and enough man made carbon footprint to allow such a melt of ice? The argument presented seems to support that these are natural events, and man has little to do with global warming. The same can be said for all the evidence of tree growth rings and evidence for temperature shifts. Warming and cooling trends are being proven as cyclical natural events so why does man really have to worry other than rebuilding after each natural disaster. Mother Nature can indeed be a bitch.
The jet stream shifts at times, like now in the US. It is in a pattern that can leave the desert southwest dry for months or even years. As happened in the 1950s and the 1930s and the 1880s and a dozen known times before that. When asked about the lengthy drought in Oklahoma a local climatologist answered â Based on past history, Oklahoma has been overdue for an extended drought. -
...means that the developing nations will not take as long as we did to get to where we are, which is being affluent enough to care about environmental quality instead of merely surviving to fight another day. It took us 100 years to get to where most Chinese have gotten in less than 30. Of course, the Progressive Green agenda threatens all of that.
These melting episodes leave clear markers in the ice core. It looks different than the layers where there wasn't melt. BTW, saying it happens on average every 150 years is misleading. Prior to the 1889 melting event it had been 700 years since the last time it happened. The further back you go in the Holocene the more common the melt events were, probably mostly because summer insolation was higher back then due to the state of Milankovitch Cycles. Here is a graph of the events back to 10,000 years ago. The green lines are melt years. http://www.gisp2.sr.unh.edu/DATA/alley1.html
There are other sources, but those are the high points. Every natural record has limitations, as one commenter pointed out Greenland's record has, so the various records must be reconciled with each other to find the matches and find what is missing from each one. And when we find that Greenland's record is missing every 150 years or so, it means there was warming then.
- - The areas classified as melt (dark pink) correspond to sites where two or three satellites detected surface melting. The satellites are measuring different physical properties at different scales and are passing over Greenland at different times. - - They never define what different physical properties are being measured. I was making an educated guess that surface snow has different properties than ice. If you have other references please share. I would love to know exactly what differences could be detected from space. From reading other reports I know NASA can tell the difference between snow and ice.
a little research on your part can tell you clearly what is meant by the term surface Ice. Some of us take time to look up what we do not understand instead of blaming others for our own ignorance. Besides if Mark dumbed down someone else's words for "all" to understand; he could misrepresent the orginial intent of NASA's report.
I think they are talking about accumulated surface SNOW melting into an icy glaze with much of it being released as runoff. A change from white snow to reflective ice is something a satellite could distinguish. I could be wrong.
...and "Muslim outreach". We're replacing all our scientists and engineers with community organizers. Perhaps they can find jobs in China.