Chief Scientific Advisor to the United Kingdom Department for Environment, Food and Rural Affairs (DEFRA). http://youtu.be/Yaf0DGVAJAg - Highlights: we're probably not going to hit the 2°C target, and we can't even rule out a 5°C world. Research suggests that every 1C warming increases the risk of extinction for 10% of all species. Even if that's a 4-fold overestimate, it's still a profound result. Events that are already occurring at only 0.8°C above pre-industrial: wildfires, more intense hurricanes, droughts, the July 2012 Greenland melt, accelerating polar ice loss, arctic sea ice decline, ocean acidification, etc. It seems that even 2°C isn't "safe". There is a new understanding of aerosol forcings, which might increase the total anthropogenic radiative forcing from previous estimate ~1.6 W/m^2 to something more like 2.1 W/m^2. The last part of the talk is about finding ways to build a broad coalition of support for improving the efficiency and robustness of our infrastructure while we simultaneously try to decarbonize and feed more people with increasingly less food productivity. Sir Robert Watson also spoke at a session "The Anthropocene: Confronting the Prospects of a +4°C World." That is a 12 minute talk, starting at about 1hr 3min into the recording.