I am working on a story that takes place roughly 2000 years after a worst-case-scenario climate apocalypse. It revolves around a society located in present-day Glacier Bay National Park on the Alaska/BC border.
I should note that in my world building, on top of the normal climate apocalypse which devastated society 2000 years ago, there is an alien race that has also been terraforming the earth for hundreds of years now, changing the atmosphere to make the climate even warmer. (I don't know if it matters but these aliens are also raising the oxygen level of the atmosphere to something similar to what existed in the Carboniferous period, primarily because I want to justify the existence of genetically engineered giant dragonflies.)
So given all that, I'm hoping to get some advice on how the landscape would have realistically transformed. I've been working off the assumption that by then the glaciers would have cut U-shaped valleys that run down the mountain into the ocean, in some places ending in fjords. However I'm unsure if 2k years is a realistic timeframe for that, and I'm curious if the rapid warming of the climate would actually melt the glaciers entirely before the glacial troughs have a chance to reach the ocean. Although it's worth pointing out that in most pictures I could find, lots of these glaciers appear to be pretty close to sea-level already.
To be hyper-specific, I want to know about the area where the "Melburn glacier" and the "Grand Pacific glacier" meet, and I'm especially interested in knowing whether I'm being realistic in assuming that the melting of those glaciers, combined with rising sea-levels, would create a waterway that connects the Tarr Inlet to the Tatshenshini River (Or at least levels the landscape to the degree that it would be easy for people to create an artificial canal there that connects the two bodies of water.)
To be more general, I'm curious about realistic projections for the climate and ecosystem of this area, the effects of glacial melting, and the effect that rising sea-levels would have on the unique landscape of Glacier bay and the surrounding area.
(Thanks for reading, I'm really excited to have discovered this website!)
For clarity, when I say "normal climate apocalypse" I mean the current projection for climate change with the assumption that there is absolutely no major effort to reduce carbon emissions or seriously curb any of the excesses of industry over the next century. (Hi, I'm extremely pessimistic about the current political and economic system.)