The Next Great Migration by Sonia Shah review – movement is central to human history

This nuanced study argues that far from being an unwelcome threat to global stability, migration and mixing are essential to human survival

A wild exodus has begun," writes Sonia Shah early on in The Next Great Migration. It is happening on every continent and in every ocean." In response to the climate crisis, plants and animals that until recently scientists thought were fixed to a particular habitat have been seeking out different surroundings. Butterflies and birds have been edging their way towards the Earth's poles; frogs and fungi are slowly climbing mountain ranges - while in the oceans, even some coral reefs are moving at the rate of a few kilometres per year. And where wild species go, humans may follow, Shah suggests, noting that more people already live outside their countries of birth than ever before, some of them pushed by war, floods, rising seas and creeping deserts.

It sounds apocalyptic. But are we wrong to think so? Shah, a US science journalist, argues in a deeply researched and counterintuitive history that much received wisdom about migration - human or otherwise - rests on a series of misconceptions. We tend to see migration as unwelcome and rare, a flight from hardship or a burden for the place of arrival. But techniques including genetic history, navigational mapping and climatology have revealed that migration and mixing are far more central to life on Earth than previously thought. They may, in fact, be our best shot at preserving biodiversity and resilient human societies".