claim: Statistical analysis of the rate of warming over different periods find that warming from 1970 to 2001 is greater than the warming from both 1860 to 1880 and 1910 to 1940.
evidence: For example, Ross McKitrick and Patrick J. Michaels conducted a statistical study of surface-temperature data regressed against socioeconomic indicators, and concluded that about half of the observed warming trend ( for 1979–2002 ) could be accounted for by the residual UHI effects in the corrected temperature data set they studied—which had already been processed to remove the ( modeled ) UHI contribution.