In a report released this week, the ‘task force on displacement’ called for better data collection and analysis on climate migration trends, and finance to help those hardest hit. “The UN currently lacks a systemwide lead, coordination mechanism, or strategy on disaster displacement, including related to climate change,” wrote the authors, who mostly represent UN agencies. They called on Secretary General Antonio Guterres to develop a response.

It is important to note that absolute scarcity doesn’t have to be on the horizon in any given resource category for this scenario to kick in. A lack of adequate supplies to meet the needs of a growing, ever more urbanized and industrialized global population is enough. Given the wave of extinctions that scientists are recording, some resources -- particular species of fish, animals, and trees, for example -- will become less abundant in the decades to come, and may even disappear altogether.