
Antarctic sea ice – rapid decreases, reduced to lowest area in 40 years - alex_young
https://www.pnas.org/content/early/2019/06/25/1906556116
======
ralusek
I think that it's important for free market advocates, myself included, to
understand something. Negative third party externalities, having direct
impacts on individuals that did not consent to the responsible transaction(s),
are fully within the responsibility of the government to regulate and/or tax.
You are not violating your principles by backing state intervention for
environmental issues.

~~~
kenpomeroy
Even still, you're assuming the government has the ability to address climate
change if given the chance. But, there would need to be global consensus and
enforcement or government intervention could actually make the problem worse
(e.g. heavy environmental regulatory burden means products get manufactured
and shipped from Asia, and actually generate more carbon emissions).

Perhaps, free market solutions a la Tesla are all we've got?

~~~
mrpopo
> Perhaps, free market solutions a la Tesla are all we've got?

Tesla is still promoting the idea of the individual car, and that electric
cars could replace the ICE car for each and every travel that it is used
currently.

If Tesla is the free market solution, then be prepared to pay the bill for
climate change.

~~~
kenpomeroy
I said Tesla was perhaps "a" solution, not "the" solution. What alternative
solutions do you propose?

~~~
mrpopo
Regarding transportation, it's in my comment. Put an end to the individual car
and promote public transportation.

Replacing ICE cars with electric cars looks like it's better than nothing, but
it's only gonna promote the business-as-usual mindset.

Today, even with limited electric car adoption, our energy consumption is
growing faster than the production of electricity from renewables is growing.
That means more energy from fossil fuels worldwide. We need to slow down until
solutions are found.

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adrianN
Doomsday messages are coming in in rapid succession. First the permafrost is
melting 70 years earlier than expected, then Greenland losing massive amounts
of ice, then glaciers that provide fresh water for hundreds of millions in
India and China disappearing at an alarming rate, now this.

And still politicians do nothing. What we need is an effort to build
renewables, insulate homes, and build charging infrastructure that rivals the
Apollo program, what we get are "freedom molecules" and "clean coal".

~~~
defterGoose
Don't forget that all the insects (the single largest link in the animalian
food chain) are dying.

Politicians long ago forgot that their _job_ is to instigate improvement in
society, and now relegate themselves to either decrying or defending the
status quo. I'm beginning to fear that the Apollo program might actually be
the greatest societal effort the US will ever undertake.

~~~
fallingfrog
I’m not sure politicians have ever seen their jobs as instigating improvements
to society. I think they see their job as to protect the interests of the
biggest contributors to their campaigns. There was a time when that was
organized labor, which is as close as you’re going to get to the “will of the
people”, but now it’s mostly big business.

~~~
NeedMoreTea
There did seem to be a tendency to try in the immediate post-war era. Even the
right, hands off, side of politics were increasing state services and
benefits. In no small part as a consequence of coming back from the war, so
soon after the previous one, generating a widespread mood of "now we must do
better". It mostly survived through the sixties, and finally died with the 73
oil crisis. That caused the chaos of the rest of the seventies that resulted
in the course we're still on today.

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martincollignon
Want to make a difference on climate change as a technologist? Feel free to
join these communities actively looking for support and with ongoing projects
(that are alive):

\- [https://climateaction.tech/](https://climateaction.tech/)

\- [https://techimpactmakers.com/](https://techimpactmakers.com/)

\- [https://www.tmrow.com/](https://www.tmrow.com/)

~~~
ForHackernews
You should also take political action. With due respect to people who are
trying to take positive individual action, it will not be enough. We've been
waiting 30 years and people are still driving SUVs. Only large scale
government policy can move the needle for an entire society. Maybe you have
political views that you find that distasteful, but unfortunately we're
running out of time, and you'll have to choose between your politics and your
future.

[https://www.sunrisemovement.org/](https://www.sunrisemovement.org/)

[http://rebellion.earth/](http://rebellion.earth/)

~~~
martincollignon
Everything will be needed - incl. political action. Not everyone wants to be
political, and people should be offered other choices.

~~~
notabee
If people don't want to be political now, they're really not going to like the
choices (or lack thereof) left after politics have failed and the crisis,
famines, and other impacts start to become apparent to the general population.
Choices are what we are rapidly running out of.

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EGreg
Getting whiplash reading this. What’s the upshot?

 _Following over 3 decades of gradual but uneven increases in sea ice
coverage, the yearly average Antarctic sea ice extents reached a record high
of 12.8 × 106 km2 in 2014, followed by a decline so precipitous that they
reached their lowest value in the 40-y 1979–2018 satellite multichannel
passive-microwave record, 10.7 × 106 km2, in 2017. In contrast, it took the
Arctic sea ice cover a full 3 decades to register a loss that great in yearly
average ice extents. Still, when considering the 40-y record as a whole, the
Antarctic sea ice continues to have a positive overall trend in yearly average
ice extents, although at 11,300 ± 5,300 km2⋅y−1, this trend is only 50% of the
trend for 1979–2014, before the precipitous decline._

~~~
alex_young
I think the visualizations help a lot here:
[https://www.pnas.org/content/pnas/early/2019/06/25/190655611...](https://www.pnas.org/content/pnas/early/2019/06/25/1906556116/F9.large.jpg)

Seems like there is a lot of extreme variance, but it's hard to imagine that
the ice is going to come back quickly from such a huge and steep decline.

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King-Aaron
I don't quite follow the results being discussed here, but from my reading am
I right in understanding that up until now there's been a gradual increasing
trend in sea ice coverage in the antarctic, which is now (as of the latest
results) drastically decreasing?

~~~
rypskar
[https://earthsky.org/earth/while-arctic-sea-ice-declines-
in-...](https://earthsky.org/earth/while-arctic-sea-ice-declines-
in-2014-antarctic-sea-ice-increases)

TLDR: He went on to say that many climate models actually predict a short-term
increase in Antarctic sea ice, under conditions of global warming. He spoke of
factors such as increasing fresh water and higher wind speeds that promote ice
growth and expansion, and, as is clear from this year’s Antarctic sea ice
maximum, these factors appear to be dominating right now.

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refurb
_Still, when considering the 40-y record as a whole, the Antarctic sea ice
continues to have a positive overall trend in yearly average ice extents_

Sounds like the trend is an increase in the overall area of ice?

~~~
ash
From the Discussion section:

> The ice covers of each of the 5 sectors of Fig. 1 and of the Southern Ocean
> as a whole have experienced considerable interannual variability over the
> past 40 y (Figs. 2–7). In fact, the Southern Ocean and 4 of the 5 sectors
> (all except the Ross Sea) have each experienced at least one period since
> 1999 when the yearly average ice extents decreased for 3 or more straight
> years only to rebound again afterward and eventually reach levels exceeding
> the extent preceding the 3 y of decreases (Figs. 2–7). This illustrates that
> the ice decreases since 2014 (Fig. 2) are no assurance that the 1979–2014
> overall positive trend in Southern Ocean ice extents has reversed to a long-
> term negative trend. Only time and an extended observational record will
> reveal whether the small increase in yearly average ice extents from 2017 to
> 2018 (Fig. 2C) is a blip in a long-term downward trend or the start of a
> rebound.

And:

> I hope that the 40-y record discussed in this paper will encourage further
> studies into the atmospheric and oceanic conditions that could have led to
> the extremely rapid 2014–2017 decline of the Antarctic sea ice cover, the
> comparably rapid decline in the mid-1970s, and the uneven but overall
> gradual increases in Antarctic sea ice coverage in the intervening decades.

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umvi
> reduced to lowest area in 40 years

Does that mean over 40 years ago it had an even lower area or that they are at
all time lows (as far as we can tell)? Could account for why my grandparents
are skeptical, they're like "yeah, yeah, this has all happened before,
environmental political fads come and go..."

~~~
tremon
The 40-year timespan marks the boundary of the current measurement regime
(satellite multichannel passive-microwave measurements). This isn't the first
time it happens, but earlier measurements may not be directly comparable.

From the article:

 _The one other several-year period during the time frame of modern
instrumental records with an estimated loss of hemispheric sea ice coverage
comparably as rapid as [the current one was] in the mid-1970s. Calculations
based on a variety of datasets [..] show rates of decrease of ∼600,000 km2 /y
for the 4 y from the start of 1973 to the start of 1977 and for the 3-y subset
from the start of 1974 to the start of 1977_

The concluding remark is helpful to reproduce in full:

 _I hope that the 40-y record discussed in this paper will encourage further
studies into the atmospheric and oceanic conditions that could have led to the
extremely rapid 2014–2017 decline of the Antarctic sea ice cover, the
comparably rapid decline in the mid-1970s, and the uneven but overall gradual
increases in Antarctic sea ice coverage in the intervening decades. More
broadly, the environmental datasets may be nearing the point where they are
long enough and rich enough to enable the linking of several of the modes and
dipoles and oscillations now spoken of separately, just as the El Niño and
Southern Oscillation phenomena were linked together years ago as ENSO; once
that further linkage happens, the understanding of Earth’s very interconnected
climate system, including the sea ice cover, could be markedly enhanced._

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myth_drannon
I just watched Like Stories of Old taking the topic of Chernobyl (HBO)
[https://www.youtube.com/watch?v=Y21TGmzHHjk](https://www.youtube.com/watch?v=Y21TGmzHHjk)
He talks about the concept of Risk Society -
[https://en.wikipedia.org/wiki/Risk_society](https://en.wikipedia.org/wiki/Risk_society)

How society responds to ecological disasters, basically don't think the
government going to tackle it, it will just ignore it.

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ablation
I posted this in another comment covering the Guardian's coverage, but figured
I'd post here too in case it got lost as this seems like a more lively
discussion.

Is there any indication what a 'tipping point' or irreversible positive
feedback loop would look like once it had started? Would it resemble a graph
such as in TFA? Or would perhaps not be an irreversible first swoop, so to
speak, but instead oscillate deeper each time?

Unknowable and unlikely, perhaps, given that it's not happened before. But a
part of me wonders what it looks like when we get to the point where the
charts and graphs don't go back up again.

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perfunctory
A related article on the _thinning_ of Antarctic ice sheets [0]. So we've got
the decrease in ice extent as well as thickness, which is equal to total
_volume_ decrease?

[0]
[https://www.theguardian.com/environment/2019/may/16/thinning...](https://www.theguardian.com/environment/2019/may/16/thinning-
of-antarctic-ice-sheets-spreading-inland-rapidly-study)

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ptah
[http://flood.firetree.net/](http://flood.firetree.net/)

