climate - 450 scenario and modelling???

the world energy report from 2009 onwards refers to a 450 scenario, meaning the global energy balance and forecasting to satbilise and maintain 450ppm of CO2 maximum.

is anyone aware of any detailed modelling or acceptance elsewhere of this? it is apparently to limit temperature rise to 2deg C max.

would appreciate some links on the discussion/acceptance and/or acknowledgement of this throughout the climate movement community.

thanks.

(p.s. am not after debate on it's applicability or otherwise, but am wondering how well known this is to climate supporters and what is being discussed on it).