Migrate northward or southward?

Where will you migrate to in the face of climate change? Will you go to a country in the Southern Hemisphere (> 45th parallel): New Zealand or Chile maybe? Or will you go to a country in the Northern Hemisphere (> 50th parallel): Canada, Russia or the Scandinavian countries? Which of the two will it be?

Earth’s land mass is mainly located in the Northern Hemisphere (67,3% of the total). Almost 40% of the Northern Hemisphere’s surface is land, against 19,1%  of the Southern Hemisphere (of which 5,5% is Antarctica).

Also, the main continents of the world are funnel-shaped. The further South you go, the less room there is. The 45th South Parallel passes for 97% through open ocean. The 60th  South Parallel does not ever hit land. More warming means that the habitable zones in the Southern hemisphere will get smaller. In the North there are – still – huge swaths of land.

Figure: Cumulative land mass by Latitude, source: andywoodruff.com

The Southern Hemisphere will warm less, because of a greater body of water and the Antarctic. The North is predicted to be up to 1.6°C warmer than the South on a Business As Usual emissions-trajectory. Also, the energy it costs to melt Antarctic ice sheets can, depending on how fast the West Antarctic ice sheet disintegrates,  delay future warming in cities such as Buenos Aires and Cape Town by 10-50 years.

Contraintuitively, the warmer North may be bad news for the South. Tropical rain bands tend to favor the warmer Hemisphere and may thus shift Northward, drying out parts of the Southern Hemisphere. At the same time, the behavior of the gulf stream and polar jet stream – and subsequent erratic weather patterns – in the Northern Hemisphere is still up for grabs.

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