Summary. A denier of global warming asserts that the recent U. S. National Climate Assessment includes statements “that are (at best) misleading”. The denier inappropriately claims the Assessment’s use of a graphic image overlaying recent annual carbon dioxide emissions and annual values of global average temperature “shows correlation, and implies causation”. The denier cites the Medieval Warming Period and the Little Ice Age, having occurred in the absence of significant change in carbon dioxide level, as showing that temperature variations need not even be correlated with carbon dioxide.
Source: email to this writer from T. Wysmuller, citing Loehle, C. and McCulloch, J. H. 2008. Correction to: A 2000-year global temperature reconstruction based on non-tree ring proxies. Energy & Environment 19: 23-100;