Be afraid. Be very very afraid

In a story that caught the attention of only the more astute climate science journalists a few weeks ago, one of the more experienced oceanographers of our time, Peter Wadhams of Cambridge University, reported that the Arctic ice cap is melting much faster than we thought. How much faster? So fast that the rate made the story seem too alarmist to take seriously.

As MSNBC's Alex Johnson reported,

Scientists had previously predicted that the summer sea ice would disappear from the Arctic by 2040. But Wadhams' measurements indicate that the thinning was already approaching 50 percent and that the ice could disappear by 2020.

"What's happening to the Earth as a whole is a catastrophe, and the disappearance of Arctic sea ice has got to be one of the first indicators of the catastrophic changes," Wadhams told ITN's Lawrence McGinty. "It's something we can see. We can see it from space - the Arctic pack ice is there, it's white, and soon it won't be there."

Sounds bad, but it was the death of two Royal Navy sailors during Wadham's submarine expedition that attracted more attention that his scientific findings. And what little reporting there was tended to add the usual skeptical observations, such as this one

Walt Meier, a research scientist at the National Snow and Ice Data Center at the University of Colorado, called Wadhams' 13-year projection "extreme, but not completely implausible," and cautioned that the thinning could simply be the result of "compression of thicker ice into a smaller region."

"It's dangerous to extrapolate into the future, especially from such a short period," Meier told on Tuesday. While Wadhams' estimates "are not totally out of line with possibility," he added, "my feeling is that estimates of 13 to 20 years for the loss of summer sea ice are overly pessimistic."

In a slightly ironic twist, however, it was Meier's own National Snow and Ice Data Center that later helped confirm those overly pessimistic findings, which received much more media attention yesterday and today.

Andrew Revkin's still cautious and brief report in the New York Times begins with

Climate scientists may have significantly underestimated the power of global warming from human-generated heat-trapping gases to shrink the cap of sea ice floating on the Arctic Ocean, according to a new study of polar trends.

More details, quite alarming in tone, appear in a joint press release from the National Snow and Ice Data Center and National Center for Atmospheric Research and are uncritically reproduced by the Environment New Service:

The study, "Arctic Sea Ice Decline: Faster Than Forecast?" will appear Tuesday in the online edition of Geophysical Research Letters. It was led by Julienne Stroeve of the National Snow and Ice Data Center and funded by the National Science Foundation and by NASA.
Stroeve and her team found that, on average, the models simulated a loss in September ice cover of 2.5 percent per decade from 1953 to 2006. The fastest rate of September retreat in any individual model was 5.4 percent per decade.

But newly available data sets, blending early aircraft and ship reports with more recent satellite measurements that are considered more reliable than the earlier records, show that the September ice actually declined at a rate of about 7.8 percent per decade during the 1953-2006 period.

Doing the math (triple the previously calculated rate), it turns out that the summer north polar ice cap may indeed have only 13 years left.

This is bad news indeed, and not just for polar bears. The resulting decline in the Earth's albedo (reflectivity) will be significant. And what follows could very well be an accelerating positive feedback loop, in which warmer waters, which absorb more heat thanks to diminishing ice cover, only serve to melt more water, and so on. The effects for northern latitudes, including the thermohaline pump in the North Atlantic, will almost certainly be ... dramatic, if not catastrophic. We're talking about one of those mythical tipping points, here folks.

If subsequent measurements confirm Wadhams and Stroeve's finding, things are about to get very very interesting.


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This actually isn't "news" the data ha been surprising to the faster melt side ofr many years. I've been skeptical of the official melt rate forcasts for the same reason (the ice is vanishing quicker than expected).

A few years back someone (I don't remember who) published a "theory" that increased soot, which accumulates on snow surfaces during the melt season was responsible. But I think that is not generally accepted.

Well, it's the first I've heard of faster melt rates. I posted a link at BlueNC.

By Robert P. (not verified) on 01 May 2007 #permalink

But newly available data sets, blending early aircraft and ship reports with more recent satellite measurements that are considered more reliable than the earlier records, show that the September ice actually declined at a rate of about 7.8 percent per decade during the 1953-2006 period.

Doing the math (triple the previously calculated rate), it turns out that the summer north polar ice cap may indeed have only 13 years left.

What math is that?

If the decay were linear, and the percentages based on the 1953 level, then 7.8 % per decade * 5.3 decades = 41%. 59% should be left, which should take 75 years to melt.

If the melting were exponential (7.8% of the remaining ice left melts in any given year) then the ice would never completely melt.

But I don't see any way to get 13 years out of these numbers.

My overriding concern is with the thermohaline pump because if the polar ice cap is melting at a much faster rate then it stands to reason that so are Greenland's glaciers and that means a much greater influx of fresh water into the northern Atlantic, reducing salinity and halting or at least severely slowing down the great Atlantic "conveyor belt". The result of that will not be pretty - that will be "interesting times" a la the old Chinese curse indeed.

You get 13 years by converting the ice loss to absolute numbers If you have 100 'units' of ice cover today and are losing 7.8 'units' per year this year, you run out of ice in 12.8 years. The percentage per year would rise in inverse proportion to the remaining amount: 7.8% this year, 8.5% next year, 9.2% the year after until you reach 100% loss of the remaining ice during the final year.

I don't know how realistic that is as my personal suspicion is that the loss will be highly non-linear. We could have much less than 13 years if that number is correct.

By Benjamin Franz (not verified) on 01 May 2007 #permalink

Oops. My bad. I misread the 7.8% as per YEAR not per DECADE. If the loss were linear we would have 12.8 DECADES. Again the non-linearities probably mean we actually have much less than that. Particularly given the loss of 14% of artic ice in just the 2004/2005 season (which, if it had continued at that rate, would have resulted in complete loss of the ice cap in only 7 years!).

By Benjamin Franz (not verified) on 01 May 2007 #permalink

Umm, the paper refers 7.8% per decade, not per year.

Particularly given the loss of 14% of artic ice in just the 2004/2005 season (which, if it had continued at that rate, would have resulted in complete loss of the ice cap in only 7 years!).

And it increased by several percent from 2005-2006, which, extrapolating linearly, means the entire earth will be frozen in a thousand years or so. C'mon; extrapolating from the noise isn't science.

These data are worrying, and need to be taken seriously. But making unjustified extrapolations based on shaky math to make disaster seem more imminent is part of the reason there are so many global warming deniers. There is far too much crying wolf going on.

If you're concerned enough to want a solution, check out My EV Diary. There is a new way to reduce carbon by 75% with three battery breakthroughs. If you're not acting on the problem, you're just a witness to the earth's catastrophe.

The math I'm talking about is quite simple: the old forecast had the summer ice disappearing in 40 years. The new research says the ice is melting three times faster than that. 40/3 = 13.3 years.

OK. Let's look at the press release:

The study indicates that, because of the disparity between the computer models and actual observations, the shrinking of summertime ice is about 30 years ahead of the climate model projections. As a result, the Arctic could be seasonally free of sea ice earlier than the IPCC- projected timeframe of any time from 2050 to well beyond 2100.

Subtract 30 years from 2050 and you get 2020, which just happens to be 13 years from now.

Oh for heaven's sake, you're comparing apples with oranges. Look at the graph. We're 30 years ahead the mean of the models . The mean of the models puts the end of summer sea ice around 2100. We're not 30 years ahead of the low end of the range. In fact we're only 5 - 10 years ahead of the trendline for one-standard deviation below the mean, which puts the end of summer sea ice well after 2050.

I agree, global warming is a big issue, but what about technological advancements? Things are already starting to run on cleaner fuels... Just imagine the CO2 removing techniques we will have availible to us in 20 years. I am no expert, but I think we have to consider the tremendous rate of technological advancement in any serious global warming debate.

By George G. (not verified) on 04 May 2007 #permalink

Counting on technological breakthroughs of tomorrow to solve today's problems is foolish. There may be unexpected obstacles. The paths that we think will lead to progress may turn out to be dead ends. Even if we find theoretical techniques, we may not be able (or politically willing) to carry them out.

Putting all of our eggs into the basket of technological development is foolish. We need to keep from burning our bridges behind us, which is what we've been doing for the last few hundred years.

By Caledonian (not verified) on 05 May 2007 #permalink

The thermohaline pump is not a myth. It is responsible for the "little ice age" in the late middle ages. The Gulf stream brings warm tropical waters to the middle latitudes, nearing Europe and Britain. The further north it goes, the cooler it gets. The cooler water sinks, dragging the rest of the Gulf Stream behind it, like a siphon hose. The cycle is interrupted when the amount of fresh water increases in the arctic waters, which are normally very salty due to the fresh water being locked up in polar ice. The reduced salinity makes the water more buoyant, as any fifth grade science student who has floated an egg in the middle of a volume of water can attest to. This reduces the amount of water in the down flow, which reduces the amount of water pulled behind it. This cycle slows, and can actually completely stop, as geological ice core samples have shown. The effect on the weather in western Europe will be the worst, as that area gets its heat from the Gulf Stream. Weather patterns will get worse, and the redistribution of ground water becomes worse, as the weather continues to elude it's familiar pattern. Flooding in some place, drought in others. This pattern can be seen now in America, where there are severe droughts in Florida and the southern States, while the midwest is under water from the severe floods. The tornadoes and thunderstorms have been getting worse, and more frequent. My home was hit by three hurricanes in 13 months, those being Frances, Jeanne, and Wilma. Two of those struck land five miles from my house, only 21 days apart. The changes are already here, and they will continue to get worse. 13 years for Ice that has been here for millions of years to disappear is a global catastrophe, and the upheavals will be extreme. People will not be able to survive if they do not prepare themselves. The good thing about preparations, is that if nothing happens, you are no worse off. But if you do not prepare, and something does happen, you will certainly be worse off. I'd rather have a survivalist's attitude and not need it, than need a survivalist's attitude, and not have it.

Noticing this thread listed today under "most emailed" -- any news?

One thought. I recall a perhaps analogous discussion about, of all things, how much money one needs to save for retirement. Most charts simply show decrement of savings per year and say that average estimates whether one's nest egg will out last one's lifespan.

Someone at Stanford Economics wrote a paper some years ago pointing out that using the longterm average is stupid, because any single extreme drop in total savings puts the whole future trend out of whack --- wrecks the average. I recall the 'Financial Engines' advisory people apply some more complicated algorithm to helping people deal with this issue, that they have to consider the possibility that one very bad year can deplete their savings so it then will drop to zero far earlier than they thought.

Same thing happening for Arctic sea ice? We kept hearing about the longterm average trend, but we're seeing, as one of the researchers posted at Realclimate……

there can be sudden big drops in sea ice.

By Hank Roberts (not verified) on 07 Jul 2007 #permalink


There has been no mention of the thickness of the ice. Apparently this is half what it was 60 years ago. So about 80% of the ice may be gone already. The larger area of open water will absorb more of the sun's heat and further speed the melting of the remaining ice. It is a positive feedback a tipping point that looks bad for Greenland's ice cap.
Pretty scary and really time to get serious about the problem.

By D. Henshaw (not verified) on 22 Oct 2007 #permalink