There is an alarmist article by Gaia Vince in the latest issue of New Scientist, called “Surviving in a warmer world”.
Its basic message is that a global rise in temperatures of just 4 degrees would lead to most current subtropical and tropical areas becoming vast deserts, leading to most people being moved to claustrophobic cities in the far north:
If we allow 20 square metres of space per person — more than double the minimum habitable space allowed per person under English planning regulation — 9 million people would need 18,000 square kilometres of land to live on. The area of Canada alone is 9.1 million square kilometres and, combined with all the other high-latitude areas, such as Alaska, Britain, Russian and Scandinavia, there should be plenty of room for everyone, even with the effects of sea-level rise.
These precious lands with access to water would be valuable food-growing areas, as well as the last oases for many species, so people would need to be housed in compact, high-rise cities. Living this closely together will bring problems of its own. Disease could easily spread through the crowded population so early warning systems will be needed to monitor any outbreaks.
Sounds nice, doesn’t it?
Anyway, given that I’m not a climate scientist, I can’t really tell how likely this scenario is.
But one thing I must comment on:
In order to survive, humans may need to do something radical: rethink our society not along geopolitical lines but in terms of resource distribution. [...] “We need to look at the world afresh and see it in terms of where the resources are, and then plan the population, food and energy production around that.”
I think they basically have some kind of planned redivision in mind, with the UN tearing down countries and creating new ones.
That is never going to happen.
If some smallish countries were lost to the sea, I guess the UN would be able to convince most countries to take their share of refugees, although most of them would be bound to end up in camps in neighbouring countries.
Alternatively, I guess some countries could try to buy new land. E.g., if Bangladesh were about to be submerged, I guess Russia might sell it a small chunk of Siberia.
I’m not convinced, though. 150 million Bangladeshis within Russia would lead to huge geopolitical change, and I’m doubtful Russia would agree to that willingly.
So I think reality would be a mixture: Some rich groups of people, or even countries, might buy new homelands in Canada or Siberia. Some peoples would be scattered across the world. And millions upon millions of people would lead hopeless lives in refugee camps.
Not neat, but much more realistic than the ultra-rational dystopia imagined by New Scientist.