Obama’s sweeping Clean Power Plan rests on a finding in Chapter 10 of Working Group I of the IPCC’s latest report, AR5 — something important and little known. See page 884, emphasis added…
“We conclude, consistent with Hegerl et al. (2007b) {i.e., chapter 9 of AR4}, that more than half of the observed increase in GMST {global mean surface temperature} from 1951 to 2010 is very likely due to the observed anthropogenic increase in GHG {greenhouse gas} concentrations.”
AR4’s statement about the effect of GHGs was similar (although put in its Summary for Policy-makers, not page 884): “Most of the observed increase is global average temperature since the mid-20th century is very likely due to the observed increase in anthropogenic greenhouse gas concentrations.”
In both AR4 and AR5 the IPCC defines “Very likely” as having a “likelihood of the occurrence/outcome” at “>90% probability”. That’s below the 95% standard usually used in both science research and making of vital public policy decisions (e.g., by the EPA and FDA).
