The revised and more aggressive climate action plan San Diego adopted this month commits officials to creating 700 acres of marshland across the city, more than triple the 220 acres of new marshland Mayor Todd Gloria had previously promised in northeastern Mission Bay.

The revised climate action plan prioritizes new marsh areas — sometimes called wetlands — because they serve the dual purpose of removing greenhouse gases like carbon dioxide from the air and fighting sea-level rise by acting as a coastal sponge.