http://www.schroders.com/en/us/…warming-of-more-than-4c/

Schroder Investment Management Limited:
“Scientific and political consensus has settled on 2°C as the acceptable limit for temperature rises, requiring concentrations to stay below 450ppm. On current trends, that limit will be breached within two decades.”

Schroders is a world-class asset manager operating from 41 offices in 27 countries across Europe, the Americas, Asia and the Middle East.