Map reading: understanding ‘human climate niche’ maps

Here is a series of worrying maps…?

They show the areas or the world that are predicted to fall outside the ‘human climate niche’ due to extreme heat. They have huge implications for where people live and patterns of migration.

But it’s important not to let these maps drive apocalyptic thinking about climate-linked migration. The implications are far reaching, but far from simple.?

The maps were created by a group of researchers wanting to understand which places on earth might become too hot to live in. They used future predictions about climate change and our existing understanding of the habitable niche to estimate the places that will become unlivable.?

The research generated a lot of headlines. A lot of the coverage focused on implications for migration. The researchers pointed out that 3 billion people currently live in the zones they predict will become uninhabitable.

Undoubtedly these changes will create new episodes of human movement, and new patterns of human settlement. But the relationship between extreme heat, habitability and migration isn’t simple.?

Don’t get me wrong, I’m not trying to downplay the extreme nature of these changes. Equally I’m not suggesting that the consequences for the people who live in these areas won’t be extreme.

But we need to get away from the simplistic view that everyone will simply leave these extreme heat zones, all at once, in a mass refugee-like exodus. We (in the West, and especially Europe) need to be careful not to imply that people will leave these zones and head to Europe. The reality is that extreme heat will create a much more complex shift in migration.

The changes shown in these maps will not happen overnight. The move from livable to unlivable will unfold over decades. Long before they become unlivable other social, economic and environmental systems may have started to falter. Long before an area becomes uninhabitable due to extreme heat, it’s likely its agricultural economy will have been eroded by drought.

Economic factors will mean many people will leave these areas seeking alternative work long before they become uninhabitable. For example, as persistent droughts erode agricultural livelihoods people will start to move. This pattern of movement will look much more like economic migration, than sudden refugee-like displacement.?

People will also move the shortest distance they can to find alternative work. Over a number of decades people will leave the extreme heat zone. But they may move out of it in several stages over a number of decades. Each time moving the shortest distance to secure work.

Some people will also stay in these areas of extreme heat. The research team behind the maps describe them as places where human life will not flourish. Many millions of people already live in situations in which environmental stressors, disasters and wars prevent them from flourishing. Although many people flee these situations, many are also trapped in them and do not move.?

The zones on the map may become areas in which people face extreme hardship, but do not necessarily leave.?

The maps show us one of the worst possible climate change scenarios in which emissions are not cut fast enough. They are not an inevitability. However we should not imagine that cutting emissions now will necessarily prevent the movement of people.?

This means we need to start planning for how this movement is managed. With the right planning it could be possible to protect millions of people. But only if migration is embraced as a form of climate change adaptation.?