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I was interested in your reference [1], which you use to argue that sea ice extent is not changing. Your suggestion turns out to be contradicted by observation

I was interested in your reference [1], which you use to argue that sea ice extent is not changing. Your suggestion turns out to be contradicted by observational evidence with very high confidence, or more briefly, wrong. The chart you link is probably OK, but it only covers a few years. To see the trend, you need a longer time base. I got this from the just-released (U.S.) national climate assessment, chapter 11 (pertaining to the Arctic -- https://science2017.globalchange.gov/chapter/11/ https://science2017.globalchange.gov/chapter/11/). See "Key Finding 3", which I'll quote in its entirety: "Arctic land and sea ice loss observed in the last three decades continues, in some cases accelerating (very high confidence). It is virtually certain that Alaska glaciers have lost mass over the last 50 years, with each year since 1984 showing an annual average ice mass less than the previous year. Based on gravitational data from satellites, average ice mass loss from Greenland was −269 Gt per year between April 2002 and April 2016, accelerating in recent years (high confidence). Since the early 1980s, annual average arctic sea ice has decreased in extent between 3.5% and 4.1% per decade, become thinner by between 4.3 and 7.5 feet, and began melting at least 15 more days each year. September sea ice extent has decreased between 10.7% and 15.9% per decade (very high confidence). Arctic-wide ice loss is expected to continue through the 21st century, very likely resulting in nearly sea ice-free late summers by the 2040s (very high confidence)." The report links to what it means by "very high confidence". I believe the chart that goes with it is: https://www.globalchange.gov/browse/indicators/indicator-arctic-sea-ice-extent https://www.globalchange.gov/browse/indicators/indicator-arc... - although really the conclusion is what matters, because it's based on much more than just one chart. This kind of report is a good place to start, because it's easy to look at small points of evidence and get the wrong conclusion, especially if you are not a climate scientist, e.g., have no publications in the area. Reports like these were made for people like us.

mkempe 9y ago
Thanks. I'm not arguing that arctic sea ice is not changing, it obviously is changing during the seasons of a year and from year to year over the last decades -- I'm pointing out that the claim that "The Arctic will never be frozen again" is wrong.
- mturmon 9y ago
  But still, according to the assessment linked: "Arctic-wide ice loss is expected to continue through the 21st century, very likely resulting in nearly sea ice-free late summers by the 2040s (very high confidence)." This is a huge change from the Arctic ecosystem of decades past.
  - mkempe 9y ago
    Yes, it would be. But this 20-year prediction is based on a linear extrapolation that obviously ignores previous cooling+warming cycles of the arctic (remember why Greenland is called such). Further, that is not a prediction that there would be zero ice in the winter ("never frozen again").
    - mturmon 9y ago
      > ... this 20-year prediction is based on a linear extrapolation ... No. It's based on a body of peer-reviewed papers reviewed by a committee of people who have studied this problem for years and decades. Unless you've sifted through these papers, gone to the conferences, and published your own work for critique, you're not qualified to reach the opposite conclusion.
      - mkempe 9y ago
        I'm crushed, I had no idea facts and science were established and driven by a committee. Is there a designated committee for every subject matter? I probably won't remember your comment in 25 years, when vast frozen expanses collide with your committee studies; will you? The last several decades have not confirmed any of the predictions driven by your revered studies, despite the agitation (see Gore) and the frauds (see Mann). The predictions have shifted, past records have been manipulated, and none of the global-warming-now-climate-change computer models fit with the past tens let alone hundreds of thousand years. Greenland was warmer a thousand years ago than today, but we must submit to the absolute authority of your committee's cataclysmic claim that within one generation there shall be no more sea ice in the Arctic summer. None of these computer models would explain or show an end of the current interglacial, and a return to the ice age, even if man-made CO2 contributions were set to zero. Instead of understanding and modeling the various climate optimums and little ice ages of the last millennia, the records have been manipulated to minimize or erase these past climate changes and maintain eschatological notions. Science is not a body of papers selected by committee -- it is a systematized, hierarchically integrated body of facts and theories. If you ignore, reject, or distort facts in order to promote your ideas, you are not a scientist but a fraud. If your notions do not account for known facts, it's not science. If your formulas and models do not integrate with known facts and do not evince some theories, it's not science. Gaining knowledge of facts and understanding scientific theories is not controlled by the gates you throw up (peer reviews, conferences, critiques). Qualification to use one's faculty of reason and to draw conclusions is not determined by social approval, nor does it require participation in the rituals erected by your beloved committees.

mkempe 9y ago

Thanks. I'm not arguing that arctic sea ice is not changing, it obviously is changing during the seasons of a year and from year to year over the last decades -- I'm pointing out that the claim that "The Arctic will never be frozen again" is wrong.

mturmon 9y ago
But still, according to the assessment linked: "Arctic-wide ice loss is expected to continue through the 21st century, very likely resulting in nearly sea ice-free late summers by the 2040s (very high confidence)." This is a huge change from the Arctic ecosystem of decades past.
- mkempe 9y ago
  Yes, it would be. But this 20-year prediction is based on a linear extrapolation that obviously ignores previous cooling+warming cycles of the arctic (remember why Greenland is called such). Further, that is not a prediction that there would be zero ice in the winter ("never frozen again").
  - mturmon 9y ago
    > ... this 20-year prediction is based on a linear extrapolation ... No. It's based on a body of peer-reviewed papers reviewed by a committee of people who have studied this problem for years and decades. Unless you've sifted through these papers, gone to the conferences, and published your own work for critique, you're not qualified to reach the opposite conclusion.
    - mkempe 9y ago
      I'm crushed, I had no idea facts and science were established and driven by a committee. Is there a designated committee for every subject matter? I probably won't remember your comment in 25 years, when vast frozen expanses collide with your committee studies; will you? The last several decades have not confirmed any of the predictions driven by your revered studies, despite the agitation (see Gore) and the frauds (see Mann). The predictions have shifted, past records have been manipulated, and none of the global-warming-now-climate-change computer models fit with the past tens let alone hundreds of thousand years. Greenland was warmer a thousand years ago than today, but we must submit to the absolute authority of your committee's cataclysmic claim that within one generation there shall be no more sea ice in the Arctic summer. None of these computer models would explain or show an end of the current interglacial, and a return to the ice age, even if man-made CO2 contributions were set to zero. Instead of understanding and modeling the various climate optimums and little ice ages of the last millennia, the records have been manipulated to minimize or erase these past climate changes and maintain eschatological notions. Science is not a body of papers selected by committee -- it is a systematized, hierarchically integrated body of facts and theories. If you ignore, reject, or distort facts in order to promote your ideas, you are not a scientist but a fraud. If your notions do not account for known facts, it's not science. If your formulas and models do not integrate with known facts and do not evince some theories, it's not science. Gaining knowledge of facts and understanding scientific theories is not controlled by the gates you throw up (peer reviews, conferences, critiques). Qualification to use one's faculty of reason and to draw conclusions is not determined by social approval, nor does it require participation in the rituals erected by your beloved committees.