Foto Shutterstock Last week, the Dutch population passed the 18 million mark. The 18-millionth new inhabitant was probably an immigrant. And that is no coincidence. Climate change means the world is on the threshold of a period of mass migration. People will be moving from the south, where it is becoming too hot, to the north. This is the message from Professor Marten Scheffer and international colleagues in an article (‘Anticipating the global redistribution of people and property’)in the scientific journal One Earth.
Four years ago, Scheffer and his colleagues introduced the concept of the human climate niche. This is the habitat in which humans have traditionally felt most at home and where we perform best. The optimum average temperature there is 13°C. The areas fitting those criteria have been much the same over the past four thousand years, but climate change is altering that. For many people in the south, their current place of residence is becoming too hot to live in.
Climate losers (red) and winners (blue). The numbers show the loss or gain in habitable area, expressed in millions of inhabitants, given a rise in temperature of 2.7°C and population growth to 9.7 billion people.
Climate niche
In an article last year in Nature Sustainability (‘Quantifying the human cost of global warming’), Scheffer and his co-authors calculated that if policies don’t change, by the end of the century a third of the global population will be living outside the optimum climate niche. By that time, the Earth might be 2.7°C hotter and home to 9.5 billion people. That would inevitably lead to huge migration flows, argue Scheffer and his colleagues in the recent article in One Earth.
A new feature of this latest article is a chart that shows where those climate migrants might end up. It is based on calculations of how much habitable territory each country gains (or loses), expressed in the number of inhabitants involved. Russia, the USA and Canada are the biggest climate winners. Global warming could make it possible for Russia to accommodate one billion (!) extra inhabitants. The USA could take an extra half billion and Canada almost another half billion. In countries such as Brazil, Australia and India, large areas of land would become uninhabitable.
The numbers are dramatic. Does that mean we are on the threshold of a disaster?
‘Not necessarily. We shouldn’t be too downhearted about this. That is also the message of our article. We don’t say exactly how many people will move, but it is likely that an awful lot of people will have to go and live somewhere else. That doesn’t have to be a disaster as long as we prepare properly for it. There are a lot of countries that need people of working age because they have ageing populations. Global warming will make a lot of new areas potentially productive. But people are needed to realize that potential.’
The calculations assume the global population will grow to 9.5 billion by the end of this century. If places get too hot for people to live, isn’t population decline more likely?
‘No. The highest birth rates are seen in sub-Saharan Africa. Rates are lowest in countries with a pleasant climate. So it’s not the case that people have fewer babies if it gets too hot; there is no proof for that. People have fewer babies when education improves, especially women’s education. Areas that are too hot will see their population decline, but mainly due to migration.’
You and your co-authors call on us to prepare for mass migration. How?
‘International agreements are needed about migration. How can you help make sure people end up in the best places? Can you use education in the countries people will be moving from to prepare them for the occupations for which there is a lot of demand in the countries they will be moving to? How should you set up the newly available land for agriculture and production? That last question would be a good one for Wageningen to tackle. Our modern agriculture has had a lot of disastrous consequences for nature and the soil. Now there is an opportunity to go back to the drawing board and start again. Social integration is important too as segregation leads to prejudice and tension. It is high time to start thinking about all this.’
In Europe, right-wing parties are doing well and xenophobia is at a peak. Is the time ripe for this?
‘There are a number of persistent misunderstandings about immigration. One is that it causes xenophobia. There is hardly any evidence for a link between the number of migrants and support for extreme right populism. Xenophobia also doesn’t have much to do with poverty as such. Western Europeans are among the richest people in the world. Tensions in society arise because people have a sense of unfairness. After 50 years of neoliberal politics, some people have become incredibly rich whereas a lot of people have lost public services and have difficulty making ends meet. Populist rhetoric channels that tension and steers it towards xenophobia.’
How do you deal with that?
‘We need to make society fairer again and restore public services. That is the crux of the problem: not the number of migrants but the unfairness in society and how it is framed.’
