Thousands of families were forced from their homes due to the recent Colorado wildfires. They add to the growing number of people—21.5 million since 2010—displaced by extreme weather. In the coming decades this trend will almost certainly accelerate, as some 200 million—possibly as many as 1 billion people—are displaced by the middle of the century.

It is debatable whether the families in Colorado can be classified as “climate migrants.” Part of the debate has to do with the challenges of attributing single extreme weather events like wildfires (PDF) to a global trend like climate change. But it also has to do with the fact that despite the large and growing population displaced by extreme weather, there is, incredibly, still no common definition of a “climate migrant.”

Internationally, legal frameworks for displacement focus on refugees, people fleeing war, violence, persecution, and other forms of conflict. They do not focus on the growing population of people affected by climate shocks and stresses. Fixing this oversight could entail giving people who are displaced by a changing climate similar protections to those afforded to refugees under these international frameworks.

There are similar opportunities for policies that support climate migrants at a national level, too, where such action is even more necessary, and where our most recent work focuses. Most forms of climate-related migration are within national borders, not across them, yet few governments have plans for these populations.

Read the full article about climate migrants by Jay Balagna, Aaron Clark-Ginsberg, and Vanessa Parks at RAND Corporation.