Canadian Ice Shelves Halve In Six Years 458
eldavojohn writes "The CBC reports on new research that shows thousand-year-old ice shelves (much different than sea ice) are breaking up and have been reduced by half in a region of Canada over the last six years. 'This summer alone saw the Serson ice shelf almost completely disappear and the Ward Hunt shelf split in half. The ice loss equals about three billion tonnes, or about 500 times the mass of the Great Pyramid of Giza.' More detailed pictures can be seen at The Conversation, with a quote from Professor Steven Sherwood, Co-Director of the University of NSW's Climate Change Research Centre: 'The real significance of this, in my view, is that this ice has reportedly been there for thousands of years. The same is true of glaciers that have recently disappeared in the Andes. These observations should dispel in one fell swoop any notion that recent global warming could be natural.'"
We need more pirates! (Score:4, Informative)
We all know by now that global warming is caused by the lack of pirates:
http://en.wikipedia.org/wiki/Flying_Spaghetti_Monster#Pirates_and_global_warming [wikipedia.org]
Re:Amazing (Score:4, Informative)
"The real significance of this, in my view, is that this ice has reportedly been there for thousands of years."
So we see the strongest warming cycle in thousands of years.
What's more likely?
That this unprecedented warming is natural and just happened to correspond with AGW.
Or that the AGW thing that scientists have been talking about for decades is doing exactly the thing they've been predicting.
True there's more nuance than that (not everywhere warms the same, etc) but the evidence has piled up pretty damn high.
Re:Why would that dispel anything? (Score:4, Informative)
Since you have no record of how fast ice shelves may have vanished in the past due to natural warming, it seems suspect to claim that this certainly proves the current rate of dissipation is due to unnatural warming...
Says who? At the very least, someone seems to have the idea that these particular ice masses have been around for thousands of years.
Yes there is warming, but it appears our activities are unrelated [carlineconomics.com].
But then what would he know? He's only the chair of a climatology department...
http://scienceblogs.com/deltoid/2011/08/murray_salby_and_conservation.php [scienceblogs.com]
Re:what do Canada's growing glaciers prove? (Score:5, Informative)
Other glaciers in Canada are *growing* (an inconvenient truth), like Helm, Pace and on Mount Logan. In one swoop, this proves......
I like it when people post references for their claims.
I tried to verify yours on my own and was not successful.
The claim that Helm Glacier is growing seems to be out right false. [wordpress.com]
The claim about Mount Logan seem to be based on an increase in height [iceagenow.com] - the assumption being that it's due to ice accumulation, but that does not translate one way or the other to the total mass of the glacier, just the thickness at one point.
I couldn't easily find what "Pace" refers to since the word "pace," as in speed, is commonly used with the word "glacier" so I couldn't verify your claim either way.
Re:Why would that dispel anything? (Score:5, Informative)
In 2008 fossil fuel burning adding 8.7 gigatons of carbon to the atmosphere, land use changes another 1.2 gigatons. Where did it go? Unless all anthropogenic CO2 is disappearing in a way that natural CO2 isn't, then we're contributing to the increase.
Re:"These observations should dispel..." (Score:2, Informative)
The height of the current interglacial was about 8000 years ago. Temperatures have been (very) slowly dropping back down since then - until recently that is. The magnitude of the current changes in the arctic are very troubling, and the rate of decrease is accelerating. The following graph shows that arctic summer ice was fairly steady at 16,000,000km^3 up until the 1990's. We are now down to 4,500,000 km^3 : http://neven1.typepad.com/.a/6a0133f03a1e37970b014e885c65ac970d-pi [typepad.com]
This has led some to characterize this as an arctic death spiral.
Data is available here:http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/data/
Re:"These observations should dispel..." (Score:1, Informative)
So I'm not one who tends to dismiss things that experts outside my field say, but this statement is quite a blatant fallacy: just because it's been that way for thousands of years doesn't mean that any change is certainly not natural. It's these types of statements that cause so many to lose credibility. It doesn't give me much faith in someone's ability to interpret complex data when he can't even construct a valid deduction from simple facts...
Just because it's in nature doesn't make it natural. Even the little ice age took a century or more to set in. We're talking major changes in a couple of decades. Most of the changes were actually in the last decade. Climate changes happen gradually. How could I possibly know that? Let's ignore climate science since most people seem to anyway. There's plenty of evidence of the climate over the last million years, glacieral gases and such, and that's not swayed many people. How about evolution and extinction for evidence of how climates change? Sudden changes cause mass extinctions. The last one happened roughly 12,000 years ago and it wiped out most megafauna. Most extinctions happen during sudden changes and mainly when two changes happen back to back. It's believed species can adapt once suddenly but they need to recover to make further major changes. The last mass extinction happened because two changes occurred within a 100,000 years. There wasn't time to recover. Such extinctions are fairly rare and yet we are facing a second one 12,000 years after the last one. A tiny blimp in geological time. Now I'm not talking great extinctions like the one 65,000,000 years ago. The smaller mass extinctions happen every few million years and some times every few hundred thousand years. There are regular climate shifts that cause evolution to make species adapt. There's strong evidence that we are supposed to be entering into a gradual cooling period leading up to another ice age. That doesn't match with the "it's all natural" theory. How do we know that? Back to that nasty science and facts people hate so much. Ice core sample prove that the cycle has been going on at least as far back as the cores record, a million years give or take a couple of hundred thousand. Soil deposits indicate that it's been going on for millions of years. The over all cycle may go back 25 million years or more with the cycles getting more extreme in the last few million years.
The real truth is there is no amount of evidence that will sway some people. We have CO2 levels that haven't existed since before Neanderthals walked the earth. We are on track to hit CO2 levels that haven't existed in 60 million years before the end of the century. We're talking 60 million years of change in a couple of hundred years. In geological terms that's like flipping a light switch. Historically the only thing that has caused change that quickly were super volcanoes and one hasn't blown in the3 last 200 years so that wasn't the cause.
Say you don't want to give up your SUV but stop claiming it's all natural.
Re:Bad phrasing (Score:5, Informative)
>If we lived back then I'm sure we'd be hearing about Anthropogenic Tectonic Drift.
The difference is that there's a physical mechanism for human effect on climate and that observations are matching calculations based on that physics.
A quick touchstone for any alternative hypothesis for explaining global temperature rises is to ask, "Does it predict stratospheric cooling?" If CO2 is trapping heat in the lower atmosphere, then we'd predict that it won't reach the stratosphere, which will then cool down. Warming due to orbital changes, solar activity, or whatnot, would warm up the stratosphere.
It's easy to find out which is happening.
Re:"These observations should dispel..." (Score:3, Informative)
AGW opponents will make any argument of convenience, but the case is straight-forward, and there was a scientific consensus on the basic details in 1979, according to an independent NAS report of that year.
Climate scientists have made *conservative* estimates of CO2 forcing and temperature predictions. The models did not predict the rapid decline of arctic ice, because they were so *conservative*. We could be in for much worse warming than what the IPCC reports say. But real scientists doing the work want to be careful about provided unbiased and factual evidence based science -- and so eschew anything that could be interpreted as hyperbole.
That is the reason why these melting icesheets give no evidence for man-made or natural climate change. The AGW argument isn't written in them. It is, after-all, a global phenomenon.
Re:"These observations should dispel..." (Score:5, Informative)
To outline an example in each of the three, statisticians have been concerned for a while about how climatologists measure mean surface temperature from weather station data and temperature proxy data (the notorious tree ring data and ice core data) that has a great deal of irregularity and adjustments to it. Economists have been concerned by the primitive economic models of carbon usage. For example, no study of the effects of "peak oil". And there's weak research on the economic effects of global warming. If one is going to decide whether or not to implement mitigating action, they should have some idea of the costs and benefits of global warming as well as the mitigating action. Computer modelers have noted the bizarre spaghetti code that builds crucial datasets (such as the Climate Research Unit's paleoclimate temperature estimate built on a huge number of datasets. Finally, mathematical modelers have noted the absence of large scale weather phenonema such as hurricanes and equatorial waves [wikipedia.org].
Second, climatology has a problem common to geology, economics, and astronomy, namely, that it is extremely hard to conduct reproducible experiments. This is a crucial flaw of climate modeling and prediction that routinely gets ignored.
Third, the field has unusual difficulty in communicating its research to the outside world due to the complexity of the field and the difficulty of generating data and models.
Fourth, there's an enduring bias due to who funds climatology research in the field of climate change. Most of the organizations want global warming to be demonstrated. It seems to me that there is a serious danger that research which doesn't support a claim of global warming (particularly, urgent global warming which would require substantial change in society in order to mitigate), is at increased risk of becoming defunded. For example, the Goddard Institution of Space Science (a NASA-run organization) and the before-mentioned Climate Research Institute have both been headed by people who have made extreme claims about the effects of global warming for decades. How would research from someone lower down in the hierarchy that doesn't fit the message coming from the top of the organization fare?
As I see it, an argument from authority (such as "over 97% of climatologists who are actively publishing on climate change and over 85% of climatologists in general agree that human influences are responsible for most of the global warming we are seeing") isn't good enough in the present circumstances.