Sustainable Carbon Emissions
Need multiple options that reduce emissions by 1 GT/year for 50 years.
S. Pacala and R. Socolow, Science, 305, 13 Aug. 2004, p. 968-972 or National Geographic (2007) or Azimuth Project (2013)
But we waited too long so now we need 2 more wedges to stabilize
R. Socolow, Bulletin of the Atomic Scientists, 27 September 2011

At current burn rates we’ll double CO2 from preindustrial levels by 2050, and quadruple it by the end of this century. We’ve got enough fossil fuels to send it to seven times its preindustrial levels. (Azimuth Project)

The safe level may be only 350 ppm (