Most of the increase will be in developing countries whose population is projected to rise from 5.6 billion in 2009 to 7.9 billion in 2050.
=== Stopnja in kontekst ===Trajnost se proučuje in upravlja čez mnogo stopenj (razin ali referentnih okvirov) časa in prostora, ter v mnogih kontekstih ekološke, socialne in ekonomske organizacije.