5 ms·

It's irrational to believe or be frightened by such alarmist claims. Current arctic sea ice extent: about 14 million km2, more than double what it was last summ

by mkempe 9y ago

It's irrational to believe or be frightened by such alarmist claims. Current arctic sea ice extent: about 14 million km2, more than double what it was last summer, as usual, and still similar to recent years. [1] On the other hand, since we are lucky to live in an interglacial, we should be more concerned about the return of ice age phenomena such as 1-2 km thick ice sheets that covered e.g. Scandinavia, Switzerland, and Seattle up to 10,000 years ago. [2] [3] [1] http://ocean.dmi.dk/arctic/icecover.uk.php http://ocean.dmi.dk/arctic/icecover.uk.php [2] https://en.wikipedia.org/wiki/Last_glacial_period#Weichselian_glaciation_(Scandinavia_and_northern_Europe) https://en.wikipedia.org/wiki/Last_glacial_period#Weichselia... [3] https://en.wikipedia.org/wiki/Cordilleran_Ice_Sheet https://en.wikipedia.org/wiki/Cordilleran_Ice_Sheet

mkempe 9y ago
Also, in relation to sea level worries: "Because of the weight of the ice, the mainland of northwest North America was so depressed that sea levels at the Last Glacial Maximum were over a hundred metres higher than they are today (measured by the level of bedrock)."
- fallingfrog 9y ago
  That's local to North America though. The continent rebounded when the ice was removed. Has nothing to do with man made climate change.
  - mkempe 9y ago
    All available facts and identifiable causes of climate change are relevant if we are interested in science. Cherry picking facts or trying to hide their significance is anti-scientific. Your three statements are anti-scientific. 1. It's not merely "local" to the NW of N America, since a similar fact is known of Scandinavia where the rebound is still ongoing and significantly changing relative sea levels. (Your "local" sleight of hand is an attempt to minimize the significance of the scientific fact, and pretend that only man-made climate change is "global".) 2. The ice sheet covering North America was larger than the current ice sheet in Antarctica, and it melted in the course of climate changes. (Your "removed" sleight of hand is an attempt to hide non-man-made causes.) 3. It's a fact that sea level is a changing relationship between oceans and lands, influenced by tectonic activity, by climate, and even by the moon. On the one hand when large amounts of water are captured in massive ice sheets, the general water level is lower; on the other hand ice sheets push the land so far down, that the relative ocean level is higher as seen from the land. Whether climate changes are appreciably due to this or that cause, relative sea level has been changing for eons, a lot. (The "nothing to do with man made climate change" is an anti-scientific attempt to dis-integrate facts and theories of past and future climate change.)
    - fallingfrog 9y ago
      If you are a russian troll, you are most likely wasting your time here on hacker news where most of the community have technical training and are quite good at detecting nonsensical responses such as these.
      - mkempe 9y ago
        Do you think ad hominems and other fallacies will get you far in life?
        fallingfrog 9y ago
        I'm just letting you know that the reason I'm not giving you a detailed rebuttal to that disjointed sequence of non sequiturs you wrote is not because I can't. It's simply a waste of my time. If it's not blindingly obvious to you why what you wrote was wrong, there's probably nothing I can say to make it more clear.
        mkempe 9y ago
        If it seems I can't perceive why I should be silent, it's because I'm blinded by the brilliance of your sophisms.
mturmon 9y ago
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.
  - 9y ago

by mkempe 9y ago

mkempe 9y ago

Also, in relation to sea level worries: "Because of the weight of the ice, the mainland of northwest North America was so depressed that sea levels at the Last Glacial Maximum were over a hundred metres higher than they are today (measured by the level of bedrock)."

fallingfrog 9y ago
That's local to North America though. The continent rebounded when the ice was removed. Has nothing to do with man made climate change.
- mkempe 9y ago
  All available facts and identifiable causes of climate change are relevant if we are interested in science. Cherry picking facts or trying to hide their significance is anti-scientific. Your three statements are anti-scientific. 1. It's not merely "local" to the NW of N America, since a similar fact is known of Scandinavia where the rebound is still ongoing and significantly changing relative sea levels. (Your "local" sleight of hand is an attempt to minimize the significance of the scientific fact, and pretend that only man-made climate change is "global".) 2. The ice sheet covering North America was larger than the current ice sheet in Antarctica, and it melted in the course of climate changes. (Your "removed" sleight of hand is an attempt to hide non-man-made causes.) 3. It's a fact that sea level is a changing relationship between oceans and lands, influenced by tectonic activity, by climate, and even by the moon. On the one hand when large amounts of water are captured in massive ice sheets, the general water level is lower; on the other hand ice sheets push the land so far down, that the relative ocean level is higher as seen from the land. Whether climate changes are appreciably due to this or that cause, relative sea level has been changing for eons, a lot. (The "nothing to do with man made climate change" is an anti-scientific attempt to dis-integrate facts and theories of past and future climate change.)
  - fallingfrog 9y ago
    If you are a russian troll, you are most likely wasting your time here on hacker news where most of the community have technical training and are quite good at detecting nonsensical responses such as these.
    - mkempe 9y ago
      Do you think ad hominems and other fallacies will get you far in life?
      - fallingfrog 9y ago
        I'm just letting you know that the reason I'm not giving you a detailed rebuttal to that disjointed sequence of non sequiturs you wrote is not because I can't. It's simply a waste of my time. If it's not blindingly obvious to you why what you wrote was wrong, there's probably nothing I can say to make it more clear.
        mkempe 9y ago
        If it seems I can't perceive why I should be silent, it's because I'm blinded by the brilliance of your sophisms.

mturmon 9y ago

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.
- 9y ago