Easterbrook excerpt: “The Marcott et al. conclusion is totally at odds with the Greenland ice core data. But why should we believe the ice core data rather than the Marcott et al. computer generated curve? Well, the ice core curve is based on thousands of isotope measurements that reflect paleotemperatures and the chronology is accurate to within about 1-3 years, whereas the Marcott et al. curve is essentially based on computer-manipulated data with multiple data types using different technologies with varying accuracy and chronology accurate only within hundreds of years.
The Marcott et al. conclusions that“Current global temperatures of the past decade … are warmer than during ~75% of the Holocene temperature history”and“Global mean temperature for the decade 2000-2009 ….are warmer than 82% of the Holocene”are clearly contrary to measured, accurate, real-time data and thus fail the Feynman test, i.e., they are wrong.
Figure 1. Comparison of Greenland ice core temperatures and Marcott et al. temperatures for the past 10,000 years. (Top curve modified from Alley, 2000 based on data from Cuffy and Clow; bottom curve modified from Marcott et al., 2013)