They say there are two commonly suggested ways to prevent global warming. mitigation and adaptation. They add migration to the list as well. People can move to cooler climates if temperatures rise across the globe. And it has happened in the past as well. So nothing new:
In recent research, we argue that the world has seen climate change before, and how it adapted then – when modern adaptive strategies were not available – may provide valuable lessons for the challenges we face today (Desmet and Rossi-Hansberg 2012):
- During the Medieval Warm Period, roughly spanning the 9th to the 14th centuries, the world experienced temperature rises of up to two degrees celsius.
According to Fagan (2008), this “brought bounty to some areas, but to others, prolonged droughts that shook established societies to their foundation”. For example, northern Europeans and Inuits benefited enormously whereas native Americans and other Mesoamerican societies lost out.
Today’s responses to climate change would not have been much help then. There certainly was no possibility of changing the course of temperature increases, and technologies to mitigate their impact were limited. Instead, as Fagan (2008) argues: “the only protection against such disasters was movement”.
The Medieval Warm Period prompted changes in trade patterns and led to important movements of people:
- During the 12th and 13th centuries – pre-dating Ricardo’s famous example of comparative advantage – England was exporting wine to France, and vineyards were found as far north as southern Norway.
With these warmer temperatures, population density in the Nordic countries increased and the Norsemen ventured out, settling first in Iceland and later in Greenland and even parts of Newfoundland (Fagan 2008).
- Higher temperatures in 13th century Mongolia have also been linked to the rise of Genghis Khan and the vastness of his empire.
- In the 1930s, the US Dust Bowl, caused by a period of severe drought, prompted the displacement of 2.5 million people; without migration, many more would have fallen prey to poverty, malnutrition and worse.
The same thing can happen even now provided migration is allowed:
We recognise that large-scale migration across countries has never been easy or costless. Suppose we introduce a border at the 45th parallel north – a circle of latitude 45 degrees north of the Earth’s equatorial plane – making migration between south and north impossible. This benefits the north, and more so if global warming is more severe. Since higher temperatures provide a productivity boost to northern latitudes, in the absence of migratory restrictions this would attract immigrants from the south, and as a result, wages would fall. But if those immigrants are not allowed in, the north no longer suffers from declining wages. In addition, rising temperatures make the south’s population accumulate at the border, thus lowering trade costs, and providing another boon to the north.
Taking the benchmark prediction of climate change of the IPCC, introducing a border at the 45th parallel north decreases the average utility effect of global warming by 0.3%, compared to free mobility. The distributional impact of global warming is an order of magnitude larger, with the difference between north and south increasing by 3.9 percentage points. In more extreme scenarios of temperature increases, the border increases the negative average utility effect of global warming by a much larger 2.9%, and the difference between north and south widens by more than 11 percentage points.
So, we may not really move to Greenland but just to cooler places:
The current emphasis on carbon taxes as a way of dealing with global warming therefore seems appropriate. But we should certainly not forget the age-old strategy of ‘movement’ as a way of adapting to climate change. Although you may not yet be planning to migrate to Greenland, the policy debate on climate change should start giving greater importance to finding ways of alleviating migratory and trade restrictions. These frictions are fundamental to our understanding of the economic costs of global warming.