Sea Level Rise Projections and Maps

[Sebastian Jones]

Theoretically, there is kind of progressions which have a limit but don't have a maximum.

You really think he meant that the human population will approach an asymptote?!

"Fortunately" we still have the catastrophic effects of the climate crisis to counter the potential for an asymptotic population trend....

[oren]

I think KK meant medical breakthroughs could modify the expected trajectory of human population, preventing the expected peaking, increasing pressure on the environment, and thus bringing about sharp sea level rise much sooner. Hope I understood correctly.
Population will off course peak due to the adverse results of climate change and the rest of the carrying capacity issues. The higher you fly, the faster you fall.

[bligh8]

Re:  The higher you fly, the faster you fall.

Terminal velocity for humans is about 240kph, so if one is falling over salt water with SLR in mind one would go splat somewhat sooner.

[Tom_Mazanec]

I'll repost my link to the model of Earth 3000 AD ("Dubia") here because I realized this is where it really belonged:
http://www.worlddreambank.org/D/DUBIA.HTM

[bbr2314]

I'll repost my link to the model of Earth 3000 AD ("Dubia") here because I realized this is where it really belonged:
http://www.worlddreambank.org/D/DUBIA.HTM

Melting 100% of Greenland by 3000AD would require approximately .1% losses each year (based on current mass balance). That would mean that the entirety of the SMB loss between 2002 and 2019, which I believe to be .1%, would be repeated EACH AND EVERY YEAR. That is a loss of 4,000 GT a year of ice, approximately 15X the mass loss we see each year today.

I feel like the impacts of such MASSIVE ice loss are always lost in these projections. If the changes since 2002 -- and 2012 in particular -- are enough to result in changes we have seen to date, a melt year where Greenland loses 2X the volume of its record loss year to date is going to potentially have exponentially worse impacts than what we have already witnessed. Even if the impacts aren't exponential, at what threshold does mass loss result in year without a summer for much of the NATL? 3X current worst to date? 4X? 5? 10X? 20X? Because if projections are correct we are going to hit each and every one of those numbers at some point in the relatively near future. And I do not believe that will be without dire consequence that temporarily halts or stalls the melting of the ice sheet (the only good result).

[vox_mundi]

Stability Check on Antarctica Reveals High Risk for Long-Term Sea-Level Rise
https://phys.org/news/2020-09-stability-antarctica-reveals-high-long-term.amp

The warmer it gets, the faster Antarctica loses ice - and much of it will then be gone forever. Consequences for the world's coastal cities and cultural heritage sites would be detrimental, from London to Mumbai, and from New York to Shanghai. That's what a team of researchers from the Potsdam Institute for Climate Impact Research, Potsdam University and New York's Columbia University has found out in their new study, published in Nature (cover story), on how much warming the Antarctic Ice Sheet can survive.

... "As the surrounding ocean water and atmosphere warm due to human greenhouse-gas emissions, the white cap on the South Pole loses mass and eventually becomes unstable. Because of its sheer magnitude, Antarctica's potential for sea-level contribution is enormous: We find that already at 2 degrees of warming, melting and the accelerated ice flow into the ocean will, eventually, entail 2.5 meters of global sea level rise just from Antarctica alone. At 4 degrees, it will be 6.5 meters and at 6 degrees almost 12 meters if these temperature levels would be sustained long enough."

Long-term change: it's not rapid, but it's forever

"Antarctica is basically our ultimate heritage from an earlier time in Earth's history. It's been around for roughly 34 million years. Now, our simulations show that once it's melted, it does not regrow to its initial state even if temperatures eventually sink again. Indeed, temperatures would have to go back to pre-industrial levels to allow its full recovery—a highly unlikely scenario. In other words: What we lose of Antarctica now is lost forever."



The animation shows the modelled long-term evolution of the Antarctic Ice Sheet under steadily increasing temperatures.

The upper panel shows the ice sheet's surface elevation change (in meters; grey shading), the ocean-induced melting at the base of the floating ice shelves (in meters per year; purple-orange shading), as well as the topography of the bed underneath the ice sheet and the surrounding ocean (in meters above the present-day sea level; blue-brown shading).

The lower panel shows the total sea-level relevant ice volume change (in meters of sea-level equivalent ; blue curve) and total ice mass flux (in gigatons per year; purple curve).

The hysteresis of the Antarctic Ice Sheet, Nature (2020).
https://www.nature.com/articles/s41586-020-2727-5