Planetary Boundaries

Climate Change

Concentrations of carbon dioxide in the atmosphere have risen from 280 parts per million (ppm) in pre-industrial times to 400 ppm in 2014—the widely recognized ceiling with regards to acceptable climate risk. The world has already started to feel the consequences: accelerated melting of the Greenland and West Antarctic ice sheets; sea level rise; and an increase in mortality in coral reefs.

Caption: Hurricane Felix over the Carribbeans.
Credit: ISS / NASA