claim: That humans are causing global warming is the position of the Academies of Science from 80 countries plus many scientific organizations that study climate science.
evidence: The Geological Society of America ( GSA ) concurs with assessments by the National Academies of Science ( 2005 ), the National Research Council ( 2006 ), and the Intergovernmental Panel on Climate Change ( IPCC, 2007 ) that global climate has warmed and that human activities ( mainly greenhouse‐gas emissions ) account for most of the warming since the middle 1900s.