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Arctic Death Spiral: More Bad News About Sea Ice

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"Arctic Death Spiral: More Bad News About Sea Ice"

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Photo: Jefferson Beck/NASA

by Michael D. Lemonick, via Climate Central

The sea ice that blankets the Arctic Ocean each winter peaked in early March this year, as usual, and is now in retreat, en route to its annual minimum extent in September. How low it will go is something scientists worry: Ice reflects lots of sunlight back into space, and when the darker ocean underneath is exposed, more sunlight is absorbed to add to global warming.

That’s the simple version of the story, but things look even worse when you dig into the details. For one thing, all that open water does re-freeze each winter, but it freezes into a relatively thin layer known as seasonal, or first-year ice. Because it’s so thin, first-year ice tends to melt back quickly the following season, giving the ocean a chance to warm things up even more in what National Snow and Ice Data Center director Mark Serreze has called a “death spiral” that could lead to ice-free Arctic summers by 2030.

But it’s worse than that, says a new analysis by scientists at the U.S. Army’s Cold Regions Research Laboratory in Hanover, N.H. “First-year ice is not just thinner, “ said Donald Perovich, lead author of a report in Geophysical Research Letters, in an interview. “We’re also beginning to realize it has other properties.” The most important: New ice is less reflective than old ice, for most of the year, anyway. It absorbs more heat from the Sun, which means it doesn’t just melt faster: It actually speeds up its own melting.

Here’s how it happens, according to Perovich. “Most of the precipitation in the Arctic,” he said, “happens at the end of summer and in the early fall.” When the snow first begins to fall, it builds on the multi-year ice, but disappears onto the patches of open ocean. Those patches eventually freeze, and the snow sticks there as well; it just forms a thinner layer. So for most of the winter, all of the ice, thick and thin, is covered with a brightly reflective blanket. That would be good as far as warming is concerned, except that for most of the winter, the Sun doesn’t rise.

When the Sun finally does rise in spring, it melts the thinner snow first, forming heat-absorbing pools on the surface of the first-year ice. The older ice eventually catches up, forming pools of its own, but since the surface is crumpled, the ponds don’t spread as widely, and they absorb less heat.

In short, the death spiral — where more melting leads to more melting — appears to be even steeper than anyone thought.

That doesn’t mean that there’s less ice literally every year. The lowest levels ever recorded happened in September of 2007; since then, coverage has been bouncing around near, but not quite at, those historic lows, and first-year ice in the winter has been near its historic highs.

“What it means,” Perovich said, “is that with more seasonal ice, the Arctic is more susceptible to an outlier kind of year.” If there’s significantly more heat in a particular year due to natural variations, in other words, there could be a huge loss of ice. It’s kind of like a staircase, Petrovic said. “It bounces around for a while, then there’s a drop to a new normal, then it bounces around.” The point, he said, is that “we now have a type of ice cover that’s even easier to knock over than it was before.”

What that means is that at some point in the not too distant future, an unusually warm summer (even for a globally warming world) could knock the ice in the Arctic ocean down another major step, and take the world closer to the time when all of it vanishes — creating a new heat-trapping region where none existed before, and pushing climate change into an even higher gear.

– Michael Lemonick covered science and the environment for TIME magazine for nearly 21 years, where he wrote more than 50 cover stories. This piece was originally published at Climate Central and was reprinted with permission.

Related Posts:

The average thickness of the Arctic sea ice cover is declining because it is rapidly losing its thick component, the multi-year ice. At the same time, the surface temperature in the Arctic is going up, which results in a shorter ice-forming season,” explains NASA senior scientist

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19 Responses to Arctic Death Spiral: More Bad News About Sea Ice

  1. Aaron Lewis says:

    Minimum sea ice area/extent was in 2007. However, current sea ice volume is less than it was in 2007. This means that the ice is getting thinner and thinner. The ice is melting from the bottom up faster than it is melting from the edges in. Thin ice is ephemeral.

    • colinc says:

      Yep, and the same thing is happening all around Antarctica, too. Alas, most the latter has probably been severely under-estimated since the area is so much greater than the Arctic, with significantly worse weather, and to the best of my knowledge receives much less human or instrument study, though that seems to be changing. Non-white signets are on the horizon.

    • Artful Dodger says:

      Aaron, minimum sea ice extent was 2007. However, minimum sea ice area occurred in 2011. As the remaining sea ice pack thins and spreads out, it’s compactness decreases.

      Neven produces an index of sea ice compactness called ‘CAPIE’. See the latest version on his blog post here:

      http://neven1.typepad.com/blog/2012/05/ijis-is-back.html

  2. Rabid Doomsayer says:

    To get a 2030 ice free minimum you need to fit a line to extent data. If you fit an exponential function to PIOMAS volume data 2016 looks good.

    Clearly the ice is thinning and while PIOMAS 2 looked a little too pessimistic, PIOMAS 3 looks to be on the money.

    I do not know which curve to fit to which data. But a line fitted to extent data is visibly not correct and overestimates how long we will have sea ice at minimum.

    I hope that fitting an exponential curve to PIOMAS volume figures is too pessimistic but the fit does look better.

    Ideally we would want to know sea ice mass, there is at least some rotten ice that gives the appearance of significant volume. If knowing mass is unrealistic then volume is the next best measure of the health of the Arctic, then area then extent.

    Unfortunately accuracy runs the other way, extent is very accurately measured. Area is affected by how we treat pools, surface or or leads. Volume requires modelling, but we are getting better.

    The US is grossly under-prepared for the changes that are inevitable in the Arctic. Long before the ice is all gone shipping and exploration will become common. One lone exploration icebreaker is not going to be sufficient. We are ceding arctic control to the Russians.

    Shipping breaking up thin ice is a feedback we have not accounted for and will be significant.

    • colinc says:

      I think at some point in the not-too-distant future we will find that Sea Ice Extent (SIE) was a poor estimation as a basis for any premise. If I remember correctly from articles I’ve seen on Neven’s Arctic Sea Ice blog (please correct me if I err) SIE is measured by overlaying a grid (1 km resolution?) on the Arctic ocean/ice. As long as any given square on the grid contains at least 15% “ice” then the entire square kilometer is considered as ice. There is no distinction made between ice-surface “melt-ponds” and utterly open, non-frozen leads of seawater. Obviously, there is also no compensation for “rotten” ice. Moreover, as recent studies have found, the oldest, thickest, multi-year ice seems to be melting fastest. This is probably due to most of the melting being a result of warmer seawater rather than warmer air and the thick ice presents a larger surface area to the warm water than it does to the air.

    • Mulga Mumblebrain says:

      Oh, Rabid, why worry if Russia controls the Arctic-or Norway, Finland or Burkina bleeding Fasso. There are far, far, greater dangers to worry about. What are you frightened that they are going to do?

  3. Peter says:

    The US is under prepared for every element of AGW- the turning off of the ‘air conditioning’ of the planet in the arctic is one unknown. As the arctic warms further- how much methane creeps up? Does C02 begin to rise 3,4, 5 ppm a year?

    The public at large has no idea what is ahead of them- which makes those disastrous events a wild card of unimaginable dimensions.

    • otter17 says:

      So, it behaves like stair steps, huh?

      I wonder who is going to be claiming that the sea ice will recover after another large drop in extent like in 2007?

      • Peter says:

        The amount of C02 in the the atmosphere each year is rising. This past year from early May- to this year over 4ppm. It may not rise this much in the next year, but then again it could rise more.

        Sea ice will not recover- even of we stopped emissions now- the warming in the pipeline would still permit an entire summer free of ice in the next few decades,

        • Mulga Mumblebrain says:

          It appears to me, in my invincible ignorance, that the loss of the Arctic summer sea ice is pretty much curtains for us. If old Lovelock is correct to say that the amount of heat absorbed by the once white, now dark, Arctic Ocean is equivalent to that absorbed by our anthropogenic emissions (if I got that little nugget of doom correct) than this must be an irreversible process now. Am I correct to imagine that the vast amount of heat sequestered by the oceans guarantees further warming, ice-loss from Greenland and Antarctica and a rapid and unstoppable destabilisation of the climate. If I am right, than our goose is already cooked.

          • John McCormick says:

            Mulga, a few scientists are trying to make connections between meltback of the Arctic sea ice and erratic Asian monsoon; arrival time, trajectory and intensity. Pakistan suffered record floods in 2010 and 2011. More to worry about.

  4. If you run into someone who says, “So what? I don’t care about those polar bears,” you can tell them that, “What happens in the Arctic doesn’t stay in the Arctic.”

    There is good reason to think that the ice melt in the Arctic is already having a big effect on the mid-latitudes. According to recent research, Arctic amplification decreases the temperature differential between the Arctic and the mid-latitudes, slowing the jet stream, causing extreme weather, whether flooding or drought, to stall out over a region. For example, high temperatures will increase evaporation, drying out a location until there is no more moisture, no moist air convection and temperatures climb further. Similarly, Rossby waves, which one sees in the swings north and south in the storm tracks swing further north and south, causing cold air to make further incursions to the south and warm air to make further incursions to the north. Thus Arctic amplification results in more extreme weather in the mid-latitudes.

    Please see:

    Francis, J. A. and S. J. Vavrus (2012), Evidence linking Arctic amplification to extreme weather in mid-latitudes, Geophys. Res. Lett., 39, L06801, doi:10.1029/2012GL051000.
    http://www.agu.org/pubs/crossref/2012/2012GL051000.shtml

    • John McCormick says:

      Timothy, Neven has a good discussion of Warm Arctic Cold Continents with several good links to new papers.

  5. mulp says:

    I’m turning 65 this year and don’t expect to live past 80 (Donna Summers was a few months younger, just one of many my age), but I want to see a foot rise in sea level from a glacial event in Greenland or Antarctic, just so I can say “told you so…” to those I know who deny Gaia its due.

    • Dennis Tomlinson says:

      Well, I’m turning 66 this year and probably won’t live past 75. My fear about your “I told you so” moment is that afterward, pulling on the reins won’t result in a “whoa”. My greatest wish is that a couple more centimeters will produce a collective “OH SHIT” moment – leaving us time to reign in catastrophe via rein pulling. But perhaps I know too little and wish for too much…

  6. Wayne Kernochan says:

    Let me echo previous commenters. Please do not repeat the assertion that “That doesn’t mean that there’s less ice literally every year. The lowest levels ever recorded happened in September of 2007; since then, coverage has been bouncing around …” To put it bluntly, that is extremely likely to be false. The correct measure is volume. According to PIOMAS — which has the best measure of volume, frequently sample-checked against reality — the decrease in the amount of Arctic sea ice has continued to follow an exponentially decreasing curve since 2007, and is now far below 2007 and below any reasonable possibility of being the same as 2007.

    I understand reporting Perovich’s remarks — he clearly is focused on area and extent, and has just as clearly not fully considered the message of PIOMAS. But it just ain’t so.

  7. John Nissen says:

    There is some relevant information on AMEG’s new blogspot, see http://a-m-e-g.blogspot.co.uk/2012/05/message-from-arctic-methane-emergency.html

    The PIOMAS sea ice volume data in figure 1 clearly shows that the sea ice is thinning rapidly, and a collapse in extent can be expected before 2016. Then the Arctic will warm even faster. It is currently warming at 1 degree per decade, which is at least 5x the global warming rate, see figure 2. As Timothy Chase says (comment 4#), Arctic warming is already having a destabilising effect on mid-latitude weather. But then we can also see (figure 3) that methane emissions are rising dramatically, which is what might be expected from Arctic warming and reduced sea ice cover. So several bad things are coming together.

    I fear that we are rapidly approaching a point of no return, where positive feedback takes over and we are helpless as global warming begins to spiral out of control. Are we going to do nothing till it’s too late, or are we going to cool the Arctic as quickly as possible to save the sea ice and prevent a methane excursion? That is the big question for society. I expect to suffer the consequences of inaction, or enjoy the fruits of action, within my lifetime. And I am turning 71.

  8. Robert in New Orleans says:

    Does anyone have any recent (within the last month)information about the rate of methane clathrate melting in the Arctic?