Arctic sea ice decline stalls out at second lowest minimum | Hacker News Reader

Arctic sea ice decline stalls out at second lowest minimum

nsidc.org

16 pointsjesperlang5 comments

It's intriguing what data is considered to be the most title-worthy in cases like this. If anything, the claims made in the first paragraph seem to undersell the severity of this, since a single data point's order statistic says little about the overall trend. Far more damming is Figure 2b, which shows linear regressions and ranges for three time periods. Unlike the order statistics in the intro/title, this figure is quite irrefutable.

> It's intriguing what data is considered to be the most title-worthy in cases like this.

I would have taken the title from this quote:

> In the Antarctic, sea ice extent is now well above average and within the range of the ten largest ice extents on record, underscoring its high year-to-year variability. The annual maximum for Antarctic sea ice typically occurs in late September or early October.

> Unlike the order statistics in the intro/title, this figure is quite irrefutable.

Polar ice waxes and wanes as the seasons progress. By some accounts summer 2020 had record temperatures in the northern hemisphere, but I think something else is going on too.

Here's a report of record cold in Australia in August 2020:

https://watchers.news/2020/08/07/tasmania-record-cold/

And a report from New Zealand from June 2020:

https://www.stuff.co.nz/national/weather-news/121823020/wint...

I think climate is more complicated than the anthropogenic catastrophists would have us believe.

Don't get confused: sea ice and ice shelves are different things. Sea ice is formed year after year from the freezing ocean water. Ice shelves are the glaciers (formed from precipitations) that cover the continental plate and extend into water. The ice shelves are definitely disappearing at a record pace.

Now the reason why the sea ice is growing is not perfectly understood, but it is hypothesized that the Southern Ocean Circumpolar Current is isolating the continent by preventing warmer water from reaching the sea ice zone, and that the decreased salinity of water near the surface (due to the melting shelves) favors sea ice formation.

Sea ice melts every year. It has little influence on sea levels or global warming. Ice shelves, on the other hand, are much more dangerous.

Figure 2b shows trends over decades, not a single year. The highest minimal ice extent recorded since 2007 is 10^6km lower than the lowest minimal extent before 1992. Further, these are all minimal annual measurements, so the fact that ice "waxes and wanes" is a red herring.

> The 14 lowest extents in the satellite era have all occurred in the last 14 years.

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