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Earth Science

Shrinking Waves May Save Antarctic Sea Ice 298

Posted by samzenpus
from the no-wake-zone dept.
sciencehabit (1205606) writes "It's a nagging thorn in the side of climatologists: Even though the world is warming, the average area of the sea ice around Antarctica is increasing. Climate models haven't explained this seeming contradiction to anyone's satisfaction—and climate change deniers tout that failure early and often. But a new paper suggests a possible explanation: Variability in the heights of ocean waves pounding into the sea ice may help control its advance and retreat."
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Shrinking Waves May Save Antarctic Sea Ice

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  • Armchair scientist (Score:4, Informative)

    by Anonymous Coward on Thursday May 29, 2014 @03:20AM (#47117349)

    Actually I've never seen a single model assume that there's a positive feedback cycle and no negative feedback cycle. All published climate models have assumed that climate is a complicated system that is stable in some conditions (implying negative feedback) and unstable in others. That's the thing about systems, they change depending on the conditions. Interestingly none of them have suggested we are all going to die next week either.

    So thanks for confirming for us something that we already know, that armchair scientists aren't worth the time of day and don't really understand shit.

  • by Anonymous Coward on Thursday May 29, 2014 @03:41AM (#47117435)

    You can't reason a man out of a position he wasn't reasoned into.

    The "climate change deniers" hold the position they do as an article of faith or wishful thinking. Scientifically the debate was over decades ago. So a collective noun to describe them like "creationists" for the anti-evolution crowd is entirely appropriate.

    If this collective noun has negative connotations then that is entirely appropriate for a group of people trying to hold back society from addressing a very serious issue.

  • by quantaman (517394) on Thursday May 29, 2014 @03:42AM (#47117447)

    Just to drive my point home:
    in this article titled 'Shrinking Waves May Save Antarctic Sea Ice' we get

    " You may like to read:
    Scientists Warn of Rising Oceans As Antarctic Ice Melts "

    what is it?! How many fingers am I supposed to be seeing here??

    Both.

    This article is talking about the increased sea ice extent. Basically the amount of the ocean that's covered ice. It affects the albedo a bit, but mostly it's an interesting mystery because you'd expect it to shrink in a warmer climate.

    The other article is talking about the decreasing ice volume. The thickness of multiyear ice on both land and sea is shrinking. This is expected given the warming climate, it's also worrying because it causes sea levels to rise.

  • by evilviper (135110) on Thursday May 29, 2014 @05:27AM (#47117723) Journal

    more heat causes more evaporation, which causes more clouds, which causes less heat.

    There is no such balancing effect. Clouds can reduce or can increase heating, both, depending on local climate and time-of-day.

    Furthermore, water vapor is a powerful greenhouse gas. You don't want more of it!

    "Because water vapor is a greenhouse gas, this results in further warming and so is a 'positive feedback' that amplifies the original warming."

    https://en.wikipedia.org/wiki/... [wikipedia.org]

    "On balance, scientists arenâ(TM)t entirely sure what effect clouds will have on global warming. Most climate models predict that clouds will amplify global warming slightly."

    http://www.earthobservatory.na... [nasa.gov]

    "Therefore, the overall net effect of contrails is positive, i.e. a warming effect. However, the effect varies daily and annually"

    https://en.wikipedia.org/wiki/... [wikipedia.org]

  • by jkflying (2190798) on Thursday May 29, 2014 @07:59AM (#47118347)

    Volume loss of sea ice doesn't affect sea levels, since it was displacing sea water to begin with. Volume of land ice on the other hand, even if it migrates to an equal volume of sea ice, will cause rising sea levels.

  • by TapeCutter (624760) on Thursday May 29, 2014 @07:59AM (#47118353) Journal

    It affects the albedo a bit, but mostly it's an interesting mystery because you'd expect it to shrink in a warmer climate.

    Counter intuitive yes, but it ceased being a mystery decades ago (largely due to climate models that would run on a retail video card these days), if anything this paper is a refinement in the details of the accepted explanation - hint fresh water freezes at a slightly higher temp than salt water. Also the sea ice has always completely melted in the Antarctic summer and its dark in winter, so Albedo is not (currently) as important down south as it is up north.

    As for the denier angle - this topic is currently ranked #10 on the climate myth list [skepticalscience.com].

    It's up at #10 because the physics of collapsing ice sheets is not well understood and thus difficult to model. Deniers depend on conflating sea ice, land ice, ice shelves, ice bergs, permafrost, ice volume, ice coverage, north pole, and south pole. Someone who is not deliberately trying to mis-inform the reader will also attempt the be clear about which particular "ice metric" they are talking about ( which brings us full circle to the main point of your post :).

  • by tbannist (230135) on Thursday May 29, 2014 @08:01AM (#47118361)

    I do, however, always trust in a dispassioned comparison of evidence, or at least, there's nothing I trust more.

    Unfortunately, that comparison is rarely disappassionate. In fact, some recent studies have found that the "just the facts" approach to education on controversial topics tends to backfire [skepdic.com]. Among the general populace, there a high tendency to acknowledge only the facts that support a pre-existing position and the ignore the facts that contradict it.

    Frankly, that's why there is an entire cottage industry built around denying something that 97% of the people researching it [iop.org] have concluded is true. However, that 97% may actually be low-balling the consensus, since James Powell [jamespowell.org] says he's reviewed 25,182 scientific articles in peer-reveiwed journals mentioning global warming and climate change since 1991 and only 26 of them reject the anthropogenic cause. That's would be a disagreement rate of about 0.1%.

    The people most qualified to evaluate the evidence seem to be in a near universal agreement that is rarely accurately represented [youtube.com] by the media.

  • by Layzej (1976930) on Thursday May 29, 2014 @08:19AM (#47118529)

    Skeptical Science has a good summary of the science. It looks like there are many contributing factors to the apparent contradiction of warming temperatures, shrinking antarctic ice volume and growing antarctic sea ice area. The new paper referenced in this article is possibly another factor: http://www.skepticalscience.co... [skepticalscience.com]

    Antarctica is a continent with 98% of the land covered by ice, and is surrounded by ocean that has much of its surface covered by seasonal sea ice. Reporting on Antarctic ice often fails to recognise the fundamental difference between sea ice and land ice. Antarctic land ice is the ice which has accumulated over thousands of years on the Antarctica landmass through snowfall. This land ice therefore is actually stored ocean water that once evaporated and then fell as precipitation on the land. Antarctic sea ice is entirely different as it is ice which forms in salt water during the winter and almost entirely melts again in the summer.

    Importantly, when land ice melts and flows into the oceans global sea levels rise on average; when sea ice melts sea levels do not change measurably but other parts of the climate system are affected, like increased absorbtion of solar energy by the darker oceans.

    To summarize the situation with Antarctic ice trends:

    Antarctic land ice is decreasing at an accelerating rate

    Antarctic sea ice is increasing despite the warming Southern Ocean

    Antarctic Land Ice is decreasing

    Measuring changes in Antarctic land ice mass has been a difficult process due to the ice sheet's massive size and complexity. However, since the 1990s satellites have been launched that allow us to measure those changes. There are three entirely different approaches, and they all agree within their measurement uncertainties. The most recent estimate of land ice change that combines estimates from these three approaches reported (Shepherd and others, 2012) that between 1992 and 2011, the Antarctic Ice Sheets overall lost 1350 giga-tonnes (Gt) or 1,350,000,000,000 tonnes into the oceans, at an average rate of 70 Gt per year (Gt/yr). Because a reduction in mass of 360 Gt/year represents an annual global-average sea level rise of 1 mm, these estimates equate to an increase in global-average sea levels by 0.19 mm/yr, or 1.9 mm per decade. Together with the land ice loss from Greenland, this represents about 30% of the observed global-average sea level rise over this period.

    Examining how this change is spread over time (Figure 1) reveals that the ice sheet as a whole was not losing or gaining ice in the early 1990s. Since then ice loss has begun, and is clearly seen to have accelerated during that time:

    Shepherd et al. 2012

    Figure 1: Estimates of total Antarctic land ice changes (bottom) and regions within it (top) and approximate sea level contributions using a combination of several different measurement techniques (Shepherd and others, 2012). Shaded areas represent the estimate uncertainty (1-sigma).

    The satellite mission that is best suited to measuring land ice mass change is the Gravity Recovery and Climate Experiment (GRACE). The GRACE satellites measure changes in Earth's gravity and these can be directly related to surface mass variations such as the Antarctic ice sheet. Recent GRACE estimates of mass change show the dramatic mass loss in West Antarctica and mass gain in East Antarctica (King and others, 2012):

    King and others, 2012

    Figure 2: a, GRACE estimate of ice-mass change (2002-2012), with ice drainage basins numbered (boldface italics where trends are statistically different to zero with 95% confidence). b, c, Basin-specific lower and upper bounds on ice-mass change, respectively, reflecting the potential systematic error in the basin estimates (King and others, 2012).

    The East Antarctic Ice Sheet is growing slightly over satellite period (Figures 1&2) but not enough to offset the other losses. It is not yet clear

  • by Layzej (1976930) on Thursday May 29, 2014 @09:15AM (#47118965)

    Your intuition fails you in this case (and the scientific method is in fact your friend). It turns out we can measure this with the CERES satellite and we find that low thick clouds cast a refreshing shadow and reflect sunlight back into space, while high wispy clouds reflect little sunlight but will trap the infrared heat beneath them.

    CERES is a package of three telescopes that watch our planet from Earth orbit. "One telescope is sensitive to ordinary sunlight," says Wielicki. "It tells us how much solar radiation is reflected from clouds or ice." The other two telescopes sense longer-wavelength infrared heat. They reveal how much heat is trapped by clouds and how much of it escapes back to space. - http://science.nasa.gov/scienc... [nasa.gov]

  • by tp1024 (2409684) on Thursday May 29, 2014 @09:18AM (#47119005)

    Well, if you had read the paper you cited then you would have written:

    He and a bunch of other people frequenting "www.scepticalscience.com" had a look at 11944 ABSTRACTS of arcticles that explicitly deal with the topics "global warming" or "global climate change". NOTHING ELSE. To put it bluntly, even the phrase "global cooling" doesn't pass muster. If the topic was something objective like "climate modelling" without explicitly putting "global warming" or "global climate change" in the topic it didn't pass muster.

    The abstracts were evaluated among the 12 people who read them and the allowed to compare notes and re-evaluate their findings, thus building further consensus among the already biased evaluators. In the end, about 8000 of those abstracts evaluated by biased examiners chosen through a biased selection process were evaluated to contain no such statement and were hence excluded. That's 66.4%. Some 32.6% were found to agree with the global warming or global climate change hypothesis necessarily expoused as a topic. Oh the surprise.

    You can't find disagreement if you close your eyes. or pretent they don't say anything.

  • by Layzej (1976930) on Thursday May 29, 2014 @10:47AM (#47120025)

    We already know how it works with peer reviewed journals. Opposing AGW is a sure way to ensure that your paper is not published. Pretty easy to get those kinds of numbers when you can control who gets published.

    So you think there is a conspiracy among all journals to keep out contrary evidence? Really? Don't you think one of them would break from their secret pact and scoop the others?

    Show me the peer reviewed article published in 1999 that correctly predicted global average temperature throughout the 2000s. Show me the article published in 2005 that correctly predicted the state of the antarctic sea ice in 2014. You can't because they don't exist.

    http://news.slashdot.org/story... [slashdot.org] - When the 1981 paper was written, temperatures in the northern hemispheres were declining, and global mean temperatures were below their 1940 levels. Despite those facts, the paper's authors confidently predicted a rise in temperature due to increasing CO2 emissions.' The prediction turns out to be remarkably accurate

    http://www.theguardian.com/env... [theguardian.com] - The paper, published on Wednesday in the journal Nature Geoscience, explores the performance of a climate forecast based on data up to 1996 by comparing it with the actual temperatures observed since. The results show that scientists accurately predicted the warming experienced in the past decade, relative to the decade to 1996, to within a few hundredths of a degree.

  • by something_wicked_thi (918168) on Thursday May 29, 2014 @12:48PM (#47121325)

    You must prove your case, which has not happened.

    Oh yes? Has it not?

    AGW makes a handful of claims. First, that the earth is getting warmer [nasa.gov].

    Second, that the oceans are getting warmer [wordpress.com].

    Third, that sea levels will rise [bhc.edu]

    Fourth, that arctic ice will retreat [skepticalscience.com].

    Fifth, that Greenland's ice will melt. [skepticalscience.com].

    Sixth, that antarctic ice will melt.

    I could go on, but let's make #7 that man is causing it. [skepticalscience.com]

    So do tell what's missing here. Again, please use scientific evidence in the peer reviewed literature. Most of the links I've provided above refer you to their sources and extra reading and come from such things as IPCC reports. And again, I'll wait.

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