A 4°C world

Nobody knows for certain what a 4°C world will look like, but the map below is one model:

On this map, brown indicates ‘Uninhabitable due to floods, drought or extreme weather’. This includes the eastern Seaboard of the U.S., to Mexico and Central America, to the middle third of South America. In Africa, Mozambique and Madagascar are gone; Asia loses much of the Indian subcontinent, including all of Pakistan; Indochina is abandoned, as is most of Indonesia

Orange is not much better: ‘Uninhabitable desert’. That’s most of the U.S. and the rest of South America, almost the entirety of Africa and the southern halves of Europe and Asia. “Deserts have encroached on (Southern Europe), rivers have dried up and the Alps are now snow-free. Goats and other hardy animals are kept at the fringes”, the map predicts.

Red is for lands lost to the rising tide (assuming +4°C adds two metres to ocean levels). This may not seem a lot, but this is where populations are concentrated. In the U.S. for instance, counties directly on the shoreline constitute less than 10% of the total land area (not including Alaska), but account for 40% of the total population.