I have a citation[0] that disagrees with your characterization, suggesting (the obvious) that while it may technically be possible for humans to live in harsh environments, they tend not to, they tend to live in a small subset of all places, and climate change will move those places everywhere, even in the first world.

"We show that for thousands of years, humans have concentrated in a surprisingly narrow subset of Earth’s available climates, characterized by mean annual temperatures around ∼13 °C. This distribution likely reflects a human temperature niche related to fundamental constraints. We demonstrate that depending on scenarios of population growth and warming, over the coming 50 y, 1 to 3 billion people are projected to be left outside the climate conditions that have served humanity well over the past 6,000 y."

Unless you are cheating by saying 'first world' without noting that the places constituting the first world will likely migrate rapidly in the coming century.

[0] https://www.pnas.org/content/117/21/11350

‘humans tend not to live in warmer regions’ is entirely different than, ‘make earth uninhabitable’ — but even in that source it shows the concentration of harsher climates as being in the third world (india, africa, south america).

This seems incorrect. Perth, Western Australia has a mean annual temperature around 18°C, and my understanding is many people find the climate here agreeable. There are warmer cities in this country which also seem to be attractive destinations for migration.

The planet will be stable under our models, but what about the humans? There are mass migration scenarios in the models and mass migration always leads to instability. Our species is capable of unspeakable violence.

Migration due to climate will happen over centuries. It's not like a war where one second it's livable and the next second, shells are flying. It's incredibly slow incremental change.

In a hypothetical world without climate change, billions of people would be moving around the world over the next century or two anyway.

I hope you’re right and I’m sorry for sounding so cynical. I live in a city that invited a climate change denier to keynote our renewable city conference. He wasn’t even a good climate change denier - we found the absolute bottom of the barrel lunatic type. That still kills me and makes me genuinely worry that we’re a little too dumb to make it out of this one with the first world intact.

Edit - I’d honestly rather not articulate my fears for the developing world.

> Humans’ ability to efficiently shed heat has enabled us to range over every continent, but a wet-bulb temperature (TW) of 35°C marks our upper physiological limit, and much lower values have serious health and productivity impacts. Climate models project the first 35°C TW occurrences by the mid-21st century. However, a comprehensive evaluation of weather station data shows that some coastal subtropical locations have already reported a TW of 35°C and that extreme humid heat overall has more than doubled in frequency since 1979.

https://advances.sciencemag.org/content/6/19/eaaw1838.full

> fringe regions

I wouldn't call India a fringe region and typically cities are hardest hit.

I'm just making assumptions here, but if an average increases by 2 degrees, that could mean that the outlier maximum temperature can reach 4-5 degrees. For areas where this temperature is already in the 45-50(Celsius), that's probably uninhabitable (at least for poor people).

This will probably mean that there will be a wave of ecological emigration moving towards the more temperate areas of the globe.

So, it's not an uninhabitable earth unless you are poor and live around the dry tropical/ecuatorial areas. And there are a lot of people there.

> Some fringe regions of the planet may become a lot harder to live in (note that climate change is not uniform, it will affect some places a lot more than others) and of course some coastal areas may experience more flooding but by and large day to day living in the first world will be similar to what it is today even with 2C of warming.

How can this be known at this point? I can certainly imagine changing weather patterns such as monsoon, drought, heat waves, cold snaps, etc not being limited to fringe regions.

Because we are already seeing it and can model for the future. See the first image in this article and note how some areas have experienced no warming while others a lot as compared to 1900.

https://www.climate.gov/news-features/climate-qa/does-global...

But I would not describe the areas experiencing change as “fringe”. Nor do I see a reason to expect the areas not experiencing change to continue not changing.

‘Experiencing change’ != ‘a lot harder to live in’

I didn’t say only fringe areas would change

In addition, while global warming makes some places harder to live, it makes others more habitable.