Satellites see Unprecedented Greenland Ice Sheet Melt

http://www.jpl.nasa.gov/news/news.cfm?release=2012-217

by anigbrowl • 14 years ago

159 117 14 years ago

jpl.nasa.gov

ktizo8• 14 years ago

Oops. I wonder if this pattern of heat domes will continue for the rest of the summer and what their frequency is. By the end of the year it might no longer be as unusual.

rosser• 14 years ago

Per TFA, this isn't actually all that unusual. Core samples suggest it happens about every 150 years or so, with the last occurrence in the late 19th Century. Indeed, one of the scientists in the article says, "this event is right on time."

Smudge2• 14 years ago

Still, I wish they'd provide a bit more information. Do we know what kind of event likely caused 1889's melting? Would it, similarly, have happened in such short a span of time, or due to a similar weather event? It's still hard to dismiss as "normal" when there are so many unanswered questions.

ktizo8• 14 years ago

On it's own, it is just freak weather, which is why I was wondering about the probability of a clump of them, given the description of the weather cycle that triggered this. Lora Koenig, the scientist you quoted, was also saying that repetitions of this in the next few years would be worrisome.

DigitalSea2• 14 years ago

This scares me. I know it's only the surface that thawed, but what happens when more than the surface melts next time around? How long can people keep denying the Earth is warming before lower-level coastal regions start to flood?

ChuckMcM• 14 years ago

Mission accomplished.

The article also states that this happens every 150 years or so and did so 150 years ago. Like winter comes every 12 months. Now it would be wonderful to understand the mechanism, we've only been watching via satellite for 30 years, so in another 150 years we'll have captured a full cycle on satellite and we will know a lot more. It would have been a much more reasonable article to say:

"For the first time NASA has captured a once in 150 year event on satellite images. ..." but you still might click the link but you wouldn't feel threatened.

Retric• 14 years ago

Ice cores from Summit show that melting events of this type occur about once every 150 years on average

It's not a 150 year cycle, it's a random event with a low probability. AKA 0.66% per year ~ 10 events per 1500 years but 3 of them could have fallen within 10 years of each other.

Steko2• 14 years ago

You've reading way to much into the "150 year cycle".

Core samples aren't accurate to the day so we really don't know if this exact event is what's happened in the past. What it really sounds like is that we know there are similar melting events that happen every century and a half or so. But unlike Winter coming every 12 months we have little idea why these events might occur or whether that's all there is and we can pack it in for another 120+ years.

DigitalSea2• 14 years ago

So I get downvoted for saying that this kind of thing scares me. I clicked the link and read the article, if you read the article correctly yourself then you would realise that this isn't an event that happens precisely every 150 years. There's nothing stopping this event happening again next year... Ever heard the weather experts say something along the lines of, "This is a 75 year weather event" or "100 year weather event" it just means the odds of it happening again are slim, not impossible but slim.

The HN community has really deteriorated as of late. People down voting comments for no warranted reason, this site is starting to become Digg...

AsylumWarden2• 14 years ago

It seems to me that there really are very few people who actually deny the earth is warming. There may be a very vocal minority in your circles but I don't see it in my travels. The only real question is how much of the warming is caused by humans and how much is part of a natural cycle. You did read the article right? This is part of a cycle. Perhaps there is some human influence on this cycle but how would the researchers know? Maybe in another 150 years when the ice sheet has already reformed and then begun to melt again repeating the cycle? Level heads are needed; not panic and politics.

jfb2• 14 years ago

There's nothing in the article about a cycle. That it happens on average every 150 years is a statistical statement, not a scientific one.

Tsagadai• 14 years ago

Many coastal cities do flood, right now, but this is mainly due to more people living on the coast in areas with lax engineering codes. Panic probably won't come until building sea walls any higher becomes too expensive in areas where sea walls and other tide restricters are required. I'd wait until a few man-made islands go under water to be sure.

brc5• 14 years ago

Based on the Greenland ice shelts melting, calculations show you're pretty good for another 28,000 years.

That doesn't take into account any change in the ocean temperature from the melted ice, and any cold changes that might create.

The current historical rate of sea level rise is about 2-3mm per century. So if you're in a coast city there's probably a couple of centuries to go. Given the rate at which man-made islands can be created (or existing land masses extended) if necessary (Dubai, Hong Kong, Manhattan) I'd say there are much bigger problems to worry about.

kaybe3• 14 years ago

What's really interesting about the whole things is how the ice flow depends on temperature - ice can be in several states which will react differently under pressure. Warmer ice will flow faster, thus more ice will flow onto the sea an melt, and the ice sheet on the land will get thinner if it gets warmer.

cpr3• 14 years ago

Near the very end:

"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 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."

Makes it a bit less scary. I think this is called burying the lede. ;-)

genki• 14 years ago

I wonder about the article title, too. How do they justify calling it "unprecedented" when they clearly state there's a precedent (melting events every 150 years on average)? Seems disingenuous at best.

Smudge2• 14 years ago

Hard to say for sure with the information provided. While there is evidence that this has happened before, this degree of melting in such a short span of time is certainly "unprecedented" for as long as we've been observing, and it may well be a different kind of event than that which caused 1889's melting.

Either way, could use plenty of clarification.

jfoutz• 14 years ago

They meant the imagery was unprecedented, not the melting. NASA is more about cool space cameras than pushing climate change. (imho)

veb• 14 years ago

I'm not sure if that makes it any less scary. I wonder what reactions are going to stem from this event? You know, to every action there is always an equal and opposite reaction.

EDIT: Explain the down-votes. Things don't just happen without something else feeling it. Just like how the Maori ate all the Moas and the Haast Eagle died because it had no more food.

2muchcoffeeman2• 14 years ago

But also 1889+150 = 2039 2039-2012 = 27

So if this sort of melting was noticeable in 1889, and we notice it again now, then maybe we are 27 years too early.

What is the variation in the melting cycle? I can't find data.

Symmetry• 14 years ago

That's 150 years on average. There isn't any cycle, its just statistical.

ry0ohki• 14 years ago

Right, considering Ireland was covered in ice only 5,000 years ago, it's hard to take much stock in short term weather hype.

mncolinlee3• 14 years ago

Way to go, HN! There's nothing quite like quibbling about semantics and praising the latest OSX while the planet burns. If we saw the same kind of Chomskyan linguistics applied to OSX Mountain Lion as we apply to climate science, we wouldn't know whether HiDPI was actually included or falsely advertised.

They didn't say melting over the Summit was unprecedented. They said the 97% melt was unprecedented in the thirty years we've been able to measure ice melts.

The last 328 consecutive months of above average global temperatures have also been unprecedented. The odds of that occurring by random chance is less than one in 3.7 x 10^99.

cpr3• 14 years ago

It might be helpful to put this in perspective.

See Burt Rutan's critique of global warming "science":

http://rps3.com/Files/AGW/EngrCritique.AGW-Science.v4.3.pdf

Page 5 in particular shows the insignificance of the current warming period, using publicly available ice core data.

His whole presentation on CAGW is worth reading, as it adds a huge amount of context and data that you'll never get from the alarmists. When you see the data in this light, you can't help but question the current CAGW orthodoxy.

vosper• 14 years ago

Note that were are talking about some degree of melting occurring over 97% of the surface of the ice sheet, not that 97% of the area previously covered in ice has melted, which is how I read the title.

From the article: "Nearly the entire ice cover of Greenland, from its thin, low-lying coastal edges to its 2-mile-thick (3.2-kilometer) center, experienced some degree of melting at its surface"

edit: poor grammar

anewguy3• 14 years ago

It's fascinating to see how supposedly objective institutions are invested in selling environmentalist panic. The greens have certainly won the PR battle.

Steko2• 14 years ago

Alternatively one might conclude that websites from across the spectrum use linkbaity headlines to drive traffic. Even my daily newspaper screams it's headline at me in all caps, the horror!

justsee10• 14 years ago

Your sentiment seems to echo this: http://whowhatwhy.com/wp-content/uploads/2012/02/395940_8421...

guylhem2• 14 years ago

Considering was called Greenland by the Vikings who also named Nova Scotia "Vinland" because grape vines grew there, would it be more likely to you that some alarmist scientists would defends their jobs and salaries by giving overperssimistic claims, and that the rest would have to follow the game or become irrelevant in the publish-or-perish world?

Just like a lemon market, except driven by fear?

I remember reading somewhere (Richard Feymann maybe?) about the initial mass or charge of some particle, an electron maybe, being far away from the truth and leading to a suppression of the publication of any "dissident" results - including a much better estimate that followed.

The scientific process took care of that by publishing revised estimates, just slightly lower and lower, until the number reached the initially conflicting estimation, but this took some time.

I do not claim to have any opinion on climate change - except to notice that a side is giving alarmist claims, which can not be disproved, or when they can and are, which are adjusted by an ad-hoc theory. From global freezing in the 70s to global warming, and now "climate change". And that the other side is giving different results and seems to be more cautious in its process, because it is facing an uphill battle like anyone who would have published a significantly lower mass.

That does not win merit points with what I know about epistemology.

anewguy3• 14 years ago

That nicely fits leftist preconceptions, but it's 100% bullshit. The biggest anti-climate change organization I know of (and the worst quality), Heartland, gets about $4 million/year from corporations. On the other hand, climate change research funding from the US governmeny alone runs about $2 billion/year, which is partially dependent on keeping up the panic and alarm.

The most influential Climate Change skeptic, Steve McIntyre, lives on savings, a pension, an blog tips.

Your worldview is so factually wrong, it could hardly be worse.

ekianjo6• 14 years ago

A NASA link with a graph without any reference/legend whatsoever (it's easy to manipulate data by playing with colors and putting a threshold in white and another in red, but if we dont know exactly what is means it's just like snake oil marketing), this is very disappointing for a agency that is supposed to produce science. This is tabloid level.

sdfasdfsdf• 14 years ago

There is a legend.

'In the image, the areas classified as "probable melt" (light pink) correspond to those sites where at least one satellite detected surface melting. The areas classified as "melt" (dark pink) correspond to sites where two or three satellites detected surface melting.'

While I do feel that the use of the word "unprecedented" was not warranted (and should be criticized), the rest of the article is fine.

ktizo8• 14 years ago

It states clearly where the data is from;

Measurements from three satellites

what the image represents;

areas classified as "probable melt" (light pink) correspond to those sites where at least one satellite detected surface melting. The areas classified as "melt" (dark pink) correspond to sites where two or three satellites detected surface melting

and who it was produced by;

Jesse Allen, NASA Earth Observatory and Nicolo E. DiGirolamo, SSAI and Cryospheric Sciences Laboratory

purely by googling the names, I find this - http://modis-snow-ice.gsfc.nasa.gov/?c=personnel

and this - http://modis-snow-ice.gsfc.nasa.gov/?c=greenland

So, on balance, I'd say they are almost definitely not just making this stuff up, which would actually be tabloid level, and they instead are actually producing actual science.

I mean, what do you think NASA are doing, given they actually have satellites and stuff? Ignoring the massive amounts of collected data and instead making up graphs to trick republicans into installing solar panels or what? I don't get it.

bobds2• 14 years ago

I believe there is climate change, there always is. The idea that we are the sole cause or that we have the power to stop it, seems a little absurd.

The best thing I've read on the topic:

http://rps3.com/Pages/Burt_Rutan_on_Climate_Change.htm

"Anthropogenic Global Warming (AGW) -Study the data and reach your own conclusions!"

acqq• 14 years ago

Burt Rutan: http://en.wikipedia.org/wiki/Burt_Rutan

"an American aerospace engineer." "a BS degree in aeronautical engineering." Not anybody who is professionally involved with climate and climate effects in any way.

To compare:

http://www2.sunysuffolk.edu/mandias/global_warming/global_wa...

"Some claim that there are 31,000 U.S. scientists and over 850 peer-reviewed papers that challenge the consensus that humans are causing climate change. Skeptical Science gave these claims the greatest benefit of the doubt and came up with this interesting factoid:

31,000 scientists represents 0.1% of US scientists that hold a BS degree or higher

850 papers represents 0.1% of the peer-reviewed papers on the subject of climate change"

Burt Rutan is just one of 0.1% above.

lmm3• 14 years ago

>I believe there is climate change, there always is. The idea that we are the sole cause or that we have the power to stop it, seems a little absurd.

There are a lot of us, and we've been pumping a lot of CO2 into the atmosphere for a long time. Things like the ozone hole or the long-term deforestation of Europe show that humanity is very capable of making substantial changes to the global climate.

bobds2• 14 years ago

We've created a lot of problems, yes. We need more energy, more food, more clean water. We need to clean up our soils, we need to plant some new forests.

The focus on cutting CO2 emissions seems misplaced.

five_star• 14 years ago

This news is a bit frightening. I believe this is the result of intense global warming.

calinet62• 14 years ago

Is this debate really happening on HN? Really guys?

Satellites see Unprecedented Greenland Ice Sheet Melt

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