claim: Global warming' and 'climate change' mean different things and have both been used for decades.
evidence: NOAA, 17 June 2015; IPCC AR5 SYR Glossary 2014, p. 120 : Climate change refers to a change in the state of the climate that can be identified ( e.g., by using statistical tests ) by changes in the mean and / or the variability of its properties and that persists for an extended period, typically decades or longer.