Qin Dahi, co-chairman of the working group for the Intergovermental Panel on Climate Change, said there were "multiple lines of independence evidence" showing the earth's atmosphere and oceans have warmed in part because of higher concentrations of greenhouse gas emissions.
The IPCC found, however, the pace at which temperatures were increasing was slowing down. Ocean waters are storing more of the energy than landmass, providing a buffer but doing little to protect against global warming.
Andrew Steer, president of the World Resources Institute, said the report confirms the debate over climate change is settled.
"We can parse the details and have a rational discussion about solutions, but we ignore these scientific warnings at our own peril," he said in a statement.
British Secretary of State for Energy and Climate Change Edward Davey's voice was among the early entrants into the fray. He said only a "deeply irresponsible government" would decide the report was worth no action at all.
"Without urgent action to cut greenhouse gas emissions this warming will continue, with potentially dangerous impacts upon our societies and economy," he said in a statement Friday. "This strengthens the case for international leaders to work for an ambitious, legally binding global agreement in 2015 to cut carbon emissions."