There has been much discourse on how long-term climate change will affect human mobility over the course of the 21st century. This column estimates the long-term welfare and mobility responses to climate change. Depending on the scenario, climate change will force between 210 and 320 million people to move, mostly within their own countries. Massive international flows of climate refugees are unlikely, except under generalised and persistent conflicts. The poorest economies will be hardest hit, thus increasing global inequality and extreme poverty.