There are a lot of predictions about how many people will migrate in response to climate change. Depending on where you look, the next few decades could see hundreds of millions—or even more than 1 billion—people pick up and move. On this episode of our Changing Climate, Changing Migration podcast, we asked Julia Blocher, of the Potsdam Institute for Climate Impact Research, to explain why the predictions vary so much. We also discussed how this movement can lead to conflict.