claim: The IPCC ( 2013 ), USGCRP ( 2017 ), and USGCRP ( 2018 ) indicate that it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-twentieth century.
evidence: The scientific consensus as of 2013[ update ], as stated in the IPCC Fifth Assessment Report, is that it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century.