By the way, what is the basis for claiming that the negative aerosol forcing estimate has been reduced? (skepticalscience.com)
The magnitude of external forcings estimated using these same model may drop by that much or more. (climateaudit.org)
The new forcing estimate comes about from a newer understanding of the role of aerosols as well as the additional radiative forcing from greenhouse gas emissions since 2005. (cato.org)