4 ms·

If you want to show a trend, give us a diagram that shows a trend. A scatter plot with a trend line would be a start, maybe. One can equally interpret the diag

If you want to show a trend, give us a diagram that shows a trend. A scatter plot with a trend line would be a start, maybe. One can equally interpret the diagram from the article as showing a fairly constant level - somewhat varying within a limited range - with 2023 being an outlier. All it tells about is the variance and without at least more year labels there is no way to read anything about the trend from it. [I'm not saying the article is wrong or right, just that it does a very bad job supporting its thesis.]

bequanna 3y ago
They did give a chart showing monthly sea ice levels for each year, but I think they didn’t want to highlight that the data is only from 1979-present. Saying this is an “all time low” over only 44 years of measurements isn’t quite as impressive.
q1w2 3y ago
I think the diagram given is pretty telling, but I agree that the words "mind-blowing" tell me that the article is not suitable for the HN crowd.
GeoAtreides 3y ago
The article isn't about showing a trend, but that's my interpretation, of course. It seems to be about why antarctic ice is important and why would be worrying if this becomes a trend. That being said, the antarctic ice coverage was remarkably steady this past years: https://nsidc.org/data/seaice_index/images/s_plot_hires.png https://nsidc.org/data/seaice_index/images/s_plot_hires.png compared with arctic ice: https://nsidc.org/data/seaice_index/images/n_plot_hires.png https://nsidc.org/data/seaice_index/images/n_plot_hires.png
osigurdson 3y ago
Is there no way for scientists to estimate these levels over the past ~500 million years in order to get a broader context?
- bequanna 3y ago
  I think this is the most useful kind of data so we can put this into context, but I’m curious how they would estimate something like this. Use sea floor core samples to estimate sea ice coverage over a specific location over time?
  - osigurdson 3y ago
    I don’t know the specifics, but often scientists are able to infer a great many things from limited data. We of course have to accept that the uncertainty will be far greater that an actual year-over-year measurement as we do now.
- jncfhnb 3y ago
  What would be the point of saying the ice today is similar to the ice 500 million years ago?
  - osigurdson 3y ago
    Because 100 years is nothing in geological time obviously. The only reason not to do it is to choose to not understand the problem as completely as possible.
    - reverius42 3y ago
      If 100 years is nothing, then the Antarctic ice levels shouldn’t change at all since we’ve been monitoring them. Which makes this even more alarming!
      - osigurdson 3y ago
        What if we knew this rate of change is commonplace in a historical context or has literally never occurred in the past. I think would be useful information.
        3y ago
gmuslera 3y ago
The one in https://climatereanalyzer.org/clim/seaice/ https://climatereanalyzer.org/clim/seaice/ (make sure you are watching the right hemisphere) is more interactive and you can see clearly year by year how for 40 years things were not so different, except this one, of course.
jncfhnb 3y ago
I strongly disagree. Some people have come to understand “outlier” as “temporary noise in the data”. That is very bad. This chart shows that 2023 is clearly multiple standard deviations lower than the historical mean, and much lower than any point in the last few decades. If your latest datapoint is a huge outlier and you have nothing to explain it you should consider feeling alarm that this is significant and perhaps a step change from historical norms.
- weinzierl 3y ago
  This is a very good point but different from my gripe with the article. If a person collapses in front of me in the street and I cannot feel a pulse I don't need a trend to take action. My issue with the article is that if there is a trend (which I suspect) they could have easily shown it. If there is no trend they should have been clear about it and they could have made an argument similar to the one you made above - if they wanted to.
  - jncfhnb 3y ago
    Eh. The inflection point that makes 2023 noteworthy is in May 2023. It seems unlikely to me that you would find a meaningful trend looking further back. If there was one, it was small. The advantage of this chart is you can see it IS a big outlier.
uoaei 3y ago
That's a pretty damn high-sigma deviation, and considering deviations in similar graphs out there (surface temperature, ocean temperature, etc.) it paints a pretty devestating picture. Though if you're not familiar with the other studies and graphs it may just seem to a layperson as "so what that could be anything".

bequanna 3y ago

They did give a chart showing monthly sea ice levels for each year, but I think they didn’t want to highlight that the data is only from 1979-present. Saying this is an “all time low” over only 44 years of measurements isn’t quite as impressive.

q1w2 3y ago

I think the diagram given is pretty telling, but I agree that the words "mind-blowing" tell me that the article is not suitable for the HN crowd.

GeoAtreides 3y ago

The article isn't about showing a trend, but that's my interpretation, of course. It seems to be about why antarctic ice is important and why would be worrying if this becomes a trend. That being said, the antarctic ice coverage was remarkably steady this past years: https://nsidc.org/data/seaice_index/images/s_plot_hires.png https://nsidc.org/data/seaice_index/images/s_plot_hires.png compared with arctic ice: https://nsidc.org/data/seaice_index/images/n_plot_hires.png https://nsidc.org/data/seaice_index/images/n_plot_hires.png

osigurdson 3y ago

Is there no way for scientists to estimate these levels over the past ~500 million years in order to get a broader context?

bequanna 3y ago
I think this is the most useful kind of data so we can put this into context, but I’m curious how they would estimate something like this. Use sea floor core samples to estimate sea ice coverage over a specific location over time?
- osigurdson 3y ago
  I don’t know the specifics, but often scientists are able to infer a great many things from limited data. We of course have to accept that the uncertainty will be far greater that an actual year-over-year measurement as we do now.
jncfhnb 3y ago
What would be the point of saying the ice today is similar to the ice 500 million years ago?
- osigurdson 3y ago
  Because 100 years is nothing in geological time obviously. The only reason not to do it is to choose to not understand the problem as completely as possible.
  - reverius42 3y ago
    If 100 years is nothing, then the Antarctic ice levels shouldn’t change at all since we’ve been monitoring them. Which makes this even more alarming!
    - osigurdson 3y ago
      What if we knew this rate of change is commonplace in a historical context or has literally never occurred in the past. I think would be useful information.
      - 3y ago

gmuslera 3y ago

The one in https://climatereanalyzer.org/clim/seaice/ https://climatereanalyzer.org/clim/seaice/ (make sure you are watching the right hemisphere) is more interactive and you can see clearly year by year how for 40 years things were not so different, except this one, of course.

jncfhnb 3y ago

I strongly disagree. Some people have come to understand “outlier” as “temporary noise in the data”. That is very bad. This chart shows that 2023 is clearly multiple standard deviations lower than the historical mean, and much lower than any point in the last few decades. If your latest datapoint is a huge outlier and you have nothing to explain it you should consider feeling alarm that this is significant and perhaps a step change from historical norms.

weinzierl 3y ago
This is a very good point but different from my gripe with the article. If a person collapses in front of me in the street and I cannot feel a pulse I don't need a trend to take action. My issue with the article is that if there is a trend (which I suspect) they could have easily shown it. If there is no trend they should have been clear about it and they could have made an argument similar to the one you made above - if they wanted to.
- jncfhnb 3y ago
  Eh. The inflection point that makes 2023 noteworthy is in May 2023. It seems unlikely to me that you would find a meaningful trend looking further back. If there was one, it was small. The advantage of this chart is you can see it IS a big outlier.

uoaei 3y ago

That's a pretty damn high-sigma deviation, and considering deviations in similar graphs out there (surface temperature, ocean temperature, etc.) it paints a pretty devestating picture. Though if you're not familiar with the other studies and graphs it may just seem to a layperson as "so what that could be anything".