(November 6, 2021 at 9:53 pm)Alan V Wrote:(June 28, 2021 at 11:07 am)Angrboda Wrote: By most models, we are or will soon pass the point at which we can't contain global warming and it will become a largely runaway process.
If that happens, it could make the majority of the earth hostile to humans in a relatively short timespan.
Do you think this will happen within 100 years? Yes or no.
No, although I can't foretell the future. The biggest variable is how humans will respond in the next several decades.
As for tipping points, different tipping points start at different temperatures and occur within a range of temperatures. So for instance, melting permafrost will release methane as a positive feedback, and that has already begun in some areas, but won't happen in other areas for decades yet. The release of methane frozen in the oceans will only happen at much higher and more delayed temperatures.
In other words, since climate change is a slowly moving process, we still have time to halt and reverse it. We can even build machines which will pull CO2 from the atmosphere and sequester it again. It all depends on how we respond. However, it is likely already too late to prevent sea-level rise at least up to some disastrous point.
But I think your assumption that "the majority of the earth could be made hostile to humans" is overstated. Some areas, certainly. Other areas, like Canada and Russia, could benefit from climate change in the short run. And remember, at a point we simply run out of affordable fossil fuels to burn, likely within this century. We will be forced into renewables even if we didn't want to transition voluntarily, by economics alone.
A lot can happen in 100 years, and people will not remain idle.
Sure - I agree with the bold point above. However it also happens that almost all of the 3rd world happens to live nearer the equator as opposed to in temperate zones. The historical reason for this is simple - you don't need as much science, infrastructure, technology, and ultimately stuff to survive in a warmer climate. This segment makes up the vast majority of people that will not be able to relocate when their village / farm / settlement is under water or doesn't see enough rain to self sustain agriculture.
The biggest problem is that those governments of countries most affected don't have the resources to help their own population, and the richer, more temperate lying countries will have exactly zero incentive to do so, in particular when the people most needing help will be from "Shithole Countries" (Donald Trump TM) containing colored people with different ideologies and religious beliefs which existentially threatens the white, conservative, Christian mind.
Assuming that the friendly world will come together to help those in need is inherently bullshit.
Look at the shambles across most of Europe when you have just a single digit million people displaced from Syria. Some rich countries took more than their fair share (eg. Germany) but by far the most refugees were stuck in Turkey for both geographical and geopolitical reasons.
In the end, nobody will want the extra burden on their own population, will claim they have their own problems, and protect their own people, to the detriment of hundreds of millions of vulnerables.