Re: GIMP 3.0.0-RC1

On 1/10/25 4:52 AM, The Natural Philosopher wrote:

On 10/01/2025 09:35, 186282@ud0s4.net wrote:

On 1/10/25 4:19 AM, The Natural Philosopher wrote:

On 10/01/2025 09:09, 186282@ud0s4.net wrote:

On 1/10/25 2:31 AM, The Natural Philosopher wrote:

On 09/01/2025 23:31, 186282@ud0s4.net wrote:

Now 100+ years from now, if all remains constant, the
   ice will have melted back some more and there might be
   a more useful exposed rim.

>
Go and calculate the mass of ice on Greenland, and its latent heat of melting, and divide that by a hundred years and tell me that somehow the sun is going to provide that level of excess energy to the planet .

>
   As I said elsewhere, I don't see Greenland melting
   anytime soon. 'Climate' suffers 'cooling periods'
   roughly every 500 years - often driven by massive
   Indonesian volcanic events (sometimes asteroids).
   Iceland may sometimes play a role.
>
   I think Greenland is mostly 'cycling' - right now
   it's slowly melting but sometime soon the climate
   may change a few degrees and it'll build up a lot
   more ice again.
>

The ice age didn't end in a century. In fact it hasn't ended, technically. We are in an interstadial.

The rate of change is the tricky part - even the Ice Ages showed us that a change over 10,000 years is too rapid for species to adapt and not go extinct.
And for Greenland's ice, a lot of it is already doomed to melt, because of the Earth's total energy imbalance has roughly doubled in the past 50 years, so it is additional thermal energy in the system that's going to have to do/go somewhere:
<https://en.wikipedia.org/wiki/Earth%27s_energy_budget#Earth's_energy_imbalance_(EEI)>
TL;DR:  its why sea level has risen by +4" since 1993.

   Well ... the 'main part' of the last ice age DID
   end pretty abruptly in terms of geological time.
   Nobody is sure exactly why - all the factors that
   co-contributed. My GUESS is that sea levels got
   low enough to destabilize the methane hydrate
   deposits. There may be proxy evidence - we'll see.
>

But the point is it took thousands of years for the ice to melt.

>
   Well ... more like maybe 1000 years.
>

While the Younger Dryas feature abrupt and massive atmospheric climate change over a few decades - way more than any modern warming or cooling - it did not immediately melt all of the ice.
>
https://www.antarcticglaciers.org/wp-content/uploads/2012/06/Post- Glacial_Sea_Level_rise2.png

>
>
   These events have "curves". ALL the ice doesn't form,
   or melt, overnight. The BULK may change quickly but
   there's always a long 'shadow'.
>
   Right NOW we're still in the shadow of the last Big
   Freeze.
>
>

Shows the actual sea level rises and the full de glaciation took *over 6000* years.
>
And continues albeit at a far slower pace, to ythis day.
>
Mountains of ice do not melt in a day, or a week, or a decade or even a millennium
>
>

   The bullshit "world flood" then happened
   as ice-dams and such failed and sent Huge
   quantities of water down river tracts in
   the northern hemisphere. I can see why so
   many people imagined the entire world was
   flooded.
>
   Thing is, the last Big Freeze happened really
   quick too. SOME evidence points to an asteroid
   hitting arctic Canada or Greenland.
>

IT may have heppened quickly, but the ice did not form overnight.
>

   All the causes/equations are difficult, hard to
   pin down, but not impossible. 25 years from now
   we'll have a much better picture. Might even be
   able to take advantage.

>
The main facts are known. No matter what happens in the atmosphere, miles deep ice sheets to not melt overnight, and nor does deep permafrost.
>
You have to be particularly ignorant of physics to believe otherwise.
>
https://en.wikipedia.org/wiki/Latent_heat

>
   Ummm ... don't think I'm "pretty ignorant" at all,
   have always researched this kind of stuff.
>

Its not a matter of resaearchm, but of phyics, and oif yoiu had reaqearched te grpah I indicated it show exactly how the oice melted and sea levels roise ovre a 600 year period of constant steady

Because its effectively an integration function, so it doesn't correlate as neatly to the source energy input change causing the melt/freeze.

   As said, 'curves'.

 No. Virtually a straight line,.
  Post the Younger Dryas, ice started melting and sea level rose a a steady rate for the next 6000 years.
 That was the 10% to 90%, and we have hadanother 5% since then, riughly.

Contemplate rate of change:  it wasn't until the rate de-accelerated in ~8000 BC that the environment became stable enough for humans to develop agriculture and give rise to civilization.

 The 90% is kinda volatile

   but the 10% sticks around for a long time,
   maybe seeds the NEXT cycle's curve.
>
   It's been about 55 million years since it ALL
   melted ... tropical jungle pole to pole. It's
   been longer since it ALL froze. Mostly we
   drift back and forth along a rough center line.
   MANY factors seem to drive the cycles.

 Yes but that is hand-wavy BS and doesn't really help answer the question of whether or not Greenland will be ice free in 100 years.
 And the physics says no. Latent heat of melting is simply too massive for that ice sheet.

One needs to start at first principles of excess heat added to the system, and then determine how it is distributed.  Some is going to go to Greenland, sure, but there's also the other 97% of the world too.

 You are in this matter plain *wrong*.
 https://www.antarcticglaciers.org/wp-content/uploads/2012/06/Post- Glacial_Sea_Level_rise2.png
Clearly shows rate of melt, but you ignored the [f]actual data.

Be aware that that graph is ~20 years out of date.
As is a lot of other references on that website.  However, this page of theirs does illustrate some of the thermal hook that was already occurring prior to where a lot of their data ends in 2004:
<https://www.antarcticglaciers.org/glaciers-and-climate/climate-change/>

https://en.wikipedia.org/wiki/Latent_heat
Shows the underlying physics, that you hand waved away.

Which is precisely why having already observed +4" (+110mm) of sea level rise over 30 years should scare the living hell out of you.
Earth's oceans' volume is 1.335 billion cubic kilometers
Surface area of Earth covered by water is 361 million km^2, which means that dividing gives an average depth = 3.698 km = 3698 meters.  A 4" (110mm) rise is an increase of +0.00002975 (= +0.002975%), which based on water's thermal coefficient of expansion is 210 x 10-6 (1/ºC) means an average temperature rise of 0.00002975/210 x 10-6 (1/ºC) = +0.142 C
Now that value might not seem to be all that much, but it is an average across the entire 3698m deep water column, and so one can then also use the latent heat of water ... 4186 J/kg·K (1 cal/g·C) ... to determine how much energy must have already been added to the oceans since 1993.
Volume of 1.335 billion km^3 * 1e+12 liters/km^3 * 4186 J/kg·K * 1kg/L
= 1.355 E+9 * E+12 * 4.186 E+3
= 5.672 E+24 Joules: estimate of excess heat already absorbed.
For context, Hiroshima was 1.5 x 10^13 joules of heating, so:
(5.672 E+24 J)/(1.5 E+13 J) = ~3.78 E+11 Hiroshima equivalents
Over (2024-1993) 31 years, its ~12 billion Hiroshima bombs per year.
-hh