IPCC 2013 states that anthropogenic forcing is 95% certain
The 2013 IPCC report states that, with 95% certainty, human influence has been the dominant cause of observed warming since the mid-20th century (IPCC 2013). Please note the increase from 90% certainty in the Fourth Assessment Report in 2007, from 66% in 2001 and from just over 50% in 1995.