
Antarctica loses three trillion tonnes of ice in 25 years - open-source-ux
https://www.bbc.co.uk/news/science-environment-44470208
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thinkcontext
Rather than focusing on the big sounding absolute number in the headline, the
more important number is the 3-fold increase since 2012. This means that the
losses are accelerating, which is very concerning.

~~~
gehwartzen
Beyond that I wish articles included the total volume of ice in Antarctica;
not that I believe 3 trillion tones of lost ice is not a big deal but I have
no idea if that represents 1% or 50% of the available total.

~~~
southern_cross
It looks like the total amount of estimated ice in Antarctica is something
like 30,000,000 cubic kilometers, give or take. In comparison, the amount of
ice being lost here probably doesn't even amount to rounding error; it's more
like just noise. (Someone else here has calculated a value of about 0.01%, but
I don't know how accurate that is.)

That's a common theme with such reports these days, BTW. The numbers quoted
can be scary at first, but looking at the bigger picture they often turn out
to fall into the margin-of-error/statistical-noise range - a bit
disconcerting, maybe, but not something to get too worked up about.

What's more interesting to me is usually what's left out of such reports. For
example, there are claims that while ice may be melting around the edges of
Antarctica (at least in certain parts of it), a lot of that may just end back
up as snow in the interior instead of actually staying in the ocean. And while
"warming waters" might be caused by climate change, they might also be due to
geothermal activity in and around Antarctica - undersea thermal vents and
such. The continent itself should have about the same level of volcanic and
geothermal activity that any other continent typically has, which of course
ebbs and flows, but it's generally hidden from view under all that ice.

~~~
lostmsu
A poor estimate is that 1 trillion tones of ice is 1000 cubic kilometers.

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mkempe
For context: there are 26.5 million cubic km of ice in Antarctica, weighing
24.3 million Gt (26.5 / 1.091).

Assuming these estimated 2,700 Gt (the rounded 3 trillion) have not been
steadily replaced by new water on top of the ice sheet [1] the reported loss
amounts to a mere 0.01% of the total ice sheet.

I don't see cause for panic.

[1] [https://www.nasa.gov/feature/goddard/nasa-study-mass-
gains-o...](https://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-
antarctic-ice-sheet-greater-than-losses)

~~~
rkul
How do you know 0.01% is not a cause for panic?

~~~
mkempe
At that rate it would take 25,000 years for 10% of the Antarctica ice sheet to
melt.

On the other hand 20,000 years ago was the peak of the last Ice Age. Sea level
was 120m lower than today. There was more ice in the Northern hemisphere's ice
sheets than there is in Antarctica. We happen to live in an interglacial, one
that is not even as warm as the previous one. It is far more reasonable to
fret over the coming return of the Ice Age than to _panic_ about minor
variations in a warm, agriculture-friendly climate.

Further, another NASA study indicated in 2015 that the Antarctica ice sheet is
growing (not shrinking) by almost 0.01% every 25 years. Did you panic over
that report? More generally, is there a specific, perfect, fixed amount of ice
that should be in Antarctica? has there ever been? by what standard?

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LinuxBender
How many feet above current sea level will I have to reside to be safe in 10
years, 20 years?

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textor
In fact only the coastal regions will suffer from sea levels rise per se. But
no height will be sufficient to guarantee your safety, sadly, because this is
not about literal Great Flood. This is about climate change and hundreds of
millions of deperate displaced immigrants from places like Bangladesh who will
make everywhere more chaotic than today. We're not prepared for the human part
of the catastrophe.

~~~
mgkimsal
> only the coastal regions will suffer from sea levels rise

that's sort of definitional, but what might be 'coastal regions' 50 years from
now might be somewhat different than today.

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iconjack
Also NASA:

Antarctic Sea Ice Reaches New Record Maximum (2014) [1]

NASA Study: Mass Gains of Antarctic Ice Sheet Greater than Losses (2015) [2]

    
    
      etc etc etc
    

[1] [https://www.nasa.gov/content/goddard/antarctic-sea-ice-
reach...](https://www.nasa.gov/content/goddard/antarctic-sea-ice-reaches-new-
record-maximum)

[2] [https://www.nasa.gov/feature/goddard/nasa-study-mass-
gains-o...](https://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-
antarctic-ice-sheet-greater-than-losses)

~~~
nherment
I think maybe these are worth reading past the title?

[1]: > While the Antarctic sea ice yearly wintertime maximum extent hit record
highs from 2012 to 2014 before returning to average levels in 2015, both the
Arctic wintertime maximum and its summer minimum extent have been in a sharp
decline for the past decades. Studies show that globally, the decreases in
Arctic sea ice far exceed the increases in Antarctic sea ice.

[2] "We’re essentially in agreement with other studies that show an increase
in ice discharge in the Antarctic Peninsula and the Thwaites and Pine Island
region of West Antarctica" ... "“Our main disagreement is for East Antarctica
and the interior of West Antarctica" ... "If the losses of the Antarctic
Peninsula and parts of West Antarctica continue to increase at the same rate
they’ve been increasing for the last two decades, the losses will catch up
with the long-term gain in East Antarctica in 20 or 30 years -- I don’t think
there will be enough snowfall increase to offset these losses."

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sgolecha
Oh Dear !!! Climate change is a slow moving disaster which we humans have not
evolved to completely comprehend. Once the oceans are not able to absorb any
more C02, the temperatures are going to soar pretty fast and that C02 will
remain in the atmosphere for a long time (unless some magic carbon capture
thing comes along..which I doubt).

~~~
AngryData
Right now ocean currents are near one full turnover from around the start of
the industrial revolution. Up until now, as deep ocean currents rose to the
surface it was exposing fresh water unladen with excess CO2, but now the
current coming up is carrying CO2 saturated water from the industrial
revolution.

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dawhizkid
When I read stories like this I'm instantly reminded how small my day to day
problems really are.

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mkempe
I don't understand this part: "In total, Antarctica has shed some 2.7 trillion
tonnes of ice since 1992, corresponding to an increase in global sea level of
more than 7.5mm."

If the melting ice of Antarctica contributes only 0.3mm per year to the annual
6mm rise of sea levels, what exactly is causing a 20x larger change?

[added] On the other hand a NASA study published in 2015 [1] indicated that
Antarctica has been steadily _accumulating_ ice, thereby "taking 0.23
millimeters per year away... If the 0.27 millimeters per year of sea level
rise attributed to Antarctica in the IPCC report is not really coming from
Antarctica, there must be some other contribution to sea level rise that is
not accounted for."

[1] [https://www.nasa.gov/feature/goddard/nasa-study-mass-
gains-o...](https://www.nasa.gov/feature/goddard/nasa-study-mass-gains-of-
antarctic-ice-sheet-greater-than-losses)

~~~
llccbb
0.3 mm/yr * 26 yr = 7.8 mm

Antarctica's contribution to sea level rise per year is fairly small. The
largest portion comes from loss of land-ice like mountain glaciers and snow
pack. Mass loss from the Greenland Ice Sheet is also substantial, contributing
about 2.7 mm/yr to sea level change. Groundwater withdrawal is a measurable
component of modern sea level rise. Aside from these mass-transfer mechanisms,
there is also ocean warming (water generally expands as it get warmer) and
salinity changes that don't affect the amount of water in the oceans, but do
affect its volume. Loss of sea ice (which floats on top of water and is not
supported from below by solid earth) does not contribute to sea level change,
as the sea ice is already displacing an amount of water equal to the amount of
ice doing the displacing.

That 2015 Jay Zwally paper should not be taken as truth, as there are
substantial reasons to doubt the impact of the findings. In that paper Zwally
uses a set of satellite laser altimeters operating over different epochs and
neglects to co-register the different platforms in an intelligent way. There
was actually major hubbub around that paper and most glaciologists recognize
the claim that "Antarctica is gaining mass" is probably incorrect.[0] Zwally
has a pretty big ego and was happy to get the publicity anyways.

[0] [https://www.scientificamerican.com/article/what-to-
believe-i...](https://www.scientificamerican.com/article/what-to-believe-in-
antarctica-rsquo-s-great-ice-debate/)

~~~
mkempe
Greenland does not contribute that much to global sea-level rise: "The
cumulative ice loss from Greenland from 1992 to 2015 was 3,600 Gt and
contributed to global sea level rise by approximately 10 mm" \-- that's less
than 0.5 mm/year. [1]

Where did you get that Greenland contribution rate?

[1] [https://www.eea.europa.eu/data-and-
maps/indicators/greenland...](https://www.eea.europa.eu/data-and-
maps/indicators/greenland-ice-sheet-3/assessment)

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ThJ
Look... Humanity... You know you could do something about this, right? ... No,
faster than that. You can do it faster. You just don't want to, do you? ...
Because you're too selfish and short-sighted! Can't you see that? ... Of
course you can't. Listen... No, listen... You're f%$&ed. Don't you get it?
You're f%$&ed, and you're making it worse, and you're refusing to listen
because you're smart enough to fly to the moon, but too dumb to save yourself!
_Sigh._

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cozzyd
I expect to see #FloridaMan stories about sea level rise before we do
something constructive like greatly increase the gas tax.

~~~
devmunchies
> something constructive like greatly increase the gas tax

and to stop subsidizing meat and dairy production and associated crops (corn,
soy).

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ssivark
Why do headlines give meaningless and absolutely context-free numbers just
because they sound large?!?! X-(

In other news: you breathe out a bazillion molecules of carbon dioxide every
breath!! /rant

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11235813213455
this type of news unfortunately won't change the consumerist nature of most
people

