The present global warming debate pays excessive attention to designating a particular year as the warmest ever (Physics Today, Physics Today 0031-9228 59 12 2006 30 https://doi.org/10.1063/1.2435671 December 2006, page 30 ) or the warmest in the past 100 years. Such declarations, begun by the Intergovernmental Panel on Climate Change (IPCC), risk missing the point that the trends are what matter most. The basis for making a claim of the “warmest year” is nothing more than calculating a mean value of temperatures recorded at several land-based stations and combining it with a similar mean over world oceans. Such a “mean” calculation can be misleading since the distribution of observing locations over land and ocean is uneven. Large areas that were only sparsely observed decades ago remain so today.
In a July 2006 report to the House Committee on Energy and Commerce, 1 Edward Wegman of the Center for Computational Statistics at George Mason University stated that the IPCC’s assessment of the 1990s as the “hottest decade in a millennium” and of 1998 as the hottest year “cannot be supported…. The paucity of data in the more remote past makes the hottest-in-a-millennium claims essentially unverifiable.”
In a 2002 report on extreme weather trends, prepared for the government of Alberta, Canada, 2 I documented that the 1930s had the hottest summers in Canada and possibly in the conterminous US. In a recent reanalysis prompted by Steve McIntyre, weblogger at http://www.climateaudit.org, NASA has now designated 1934 as the hottest year in the US and not 1998 as previously claimed.
As someone who has spent more than 50 years in the science of weather and climate, I find this designation of “warmest year” misleading and almost meaningless.
