At Wired Gaia Vince argues that climate change will drive a mass migration the “global south” to the developed countries of the north:
The global map of today’s climate impacts, and those modeled for the coming decades as temperatures continue to rise in this century, makes it clear that people will have to retreat from large swathes of the tropics, which will become unlivable for at least parts of the year, from coastlines as sea levels rise and weather becomes more extreme, and from low-lying islands. Infrastructure adaptations will not save us, and agriculture will become impossible in places which are now breadbaskets supplying millions of people. Where will they move to? Largely, northwards, to expanded cities, and entirely new cities that will need to be built on the habitable fringes of Europe, Asia, and North America. Managed well, this migration could supply a much-needed population boost to countries with worker shortages due to low birth rates, and it could help reduce poverty in some of the worst-hit nations. Managed badly, it will be a catastrophic upheaval with huge loss of life.
I agree that the mass migration from south to north is inevitable but I don’t think you need to resort to anthropogenic climate change to get there. Climate change for any reason whatever is sufficient and, frankly, the climate is always changing. The enormous and growing populations in the “global south” are moving to Europe, the United States, Canada, Australia and New Zealand whatever we do to reduce carbon emissions. There are many reasons for the move. The utter dysfunction of their governments resulting in weak economies. The perception that there are jobs and/or government handouts to be had here.
We are likely to see considerable migration from Central and South America for the foreseeable future while Europe is likely to see immigration from Africa and the Middle East. A little back-of-the-envelope calculation shows the economic burden that will create. My estimates suggest that if just 10% of Central and South America’s children and their parents come here it will increase our government spending by about a half trillion per year.
There will be no mass migration north of either plants or animals because of AGW. That is merely racial fear mongering. And anyway, we are getting mass human migration to the north for economic reasons.
It has to be remembered that the models predict that almost all of the global warming will be at high latitudes 50° plus. The tropics will have only marginal warming, largely because the surface is mostly water in the tropics, which buffers temperature changes, and the tropics already have high solar insolation.
On the whole, tropical and subtropical plants and animals will see their habitats expand. Humans will especially benefit from a massive expansion of arable land in Canada, Scandinavia, and Russia. The cost of shipping from China to Europe will fall by 60%, once the Northern route opens in the Arctic.
PS. The last few 20 or 30 million years have seen extraordinarily low carbon dioxide levels, to the point where C3 photosynthesis (RUBISCO) is negatively affected. The RUBISCO enzyme complex catalyzes both the reduction of carbon dioxide to a three-carbon intermediate, and the oxidation of the intermediate. The relative concentrations of oxygen and carbon dioxide determine the direction of the reaction.
C3 photosynthesis shuts down at about half the current carbon dioxide level. One benefit of substantially higher carbon dioxide is that there has been significant increase in crop productivity world-wide.
C4 photosynthesis first showed up in grasses as a response to low carbon dioxide levels.
That’s pretty much what I wrote.