One of the most common and easily debunked claims by denialists is that there is a massive global conspiracy on the part of the climate science community to deliberately and fraudulently overstate the severity of present climatic conditions (e.g. temperature, CO2 levels, etc.) relative to the paleoclimatic record in order to make the (non-existent in their minds) threat of anthropogenic climate change more frightening to the public.
The climate community is doing this presumably to continue their grant-funded lives of obscene wealth and debauchery. Or to cripple the American economy by destroying capitalism [ha!] in order to further a UN-run, communist world government. Or something. In any event, among their frequent targets for such ludicrous conspiracy theories are Jim Hansen (who they believe in his spare time has single-handedly “fabricated” global warming by altering the GISTEMP temperature record; presumably his free time and mendacity are so great that he has been able to similarly propagate this faked warming signal throughout the biosphere), Phil Jones (likewise, but for the HadCRUT record instead), and perhaps most of all Michael Mann- for his temperature reconstructions of North America over the past two millennia. The steady blast of fetid hot air directed at Mann for his imagined attempts to exaggerate current climatic conditions relative to the past could, redirected through a turbine, easily comprise a stabilization wedge all its own.
So it is with much amusement that those in the reality-based community note papers like the one published in today’s issue of Nature here (or here) entitled “Atlantic hurricanes and climate over the past 1,500 years” by one Michael Mann- along with coauthors Jeffery Donnelly, Jonathan Woodruff, and Zhihua Zhang. The Mann et al. paper is a relatively straightforward attempt to reconstruct Atlantic hurricane activity over the past 1.5 ka, employing multiple (although admittedly sparse) regional overwash sediment records in an attempt to create a basin-wide record of landfalling hurricanes. This reconstruction is then compared against statistical modeling based on reconstructions of several climatic (sea surface temperature, Nino 3, and North Atlantic Oscillation) records.
Naturally Mann- no doubt twirling his mustache and laughing manically- has determined through premeditation and statistical voodoo that recent Atlantic hurricane activity is completely unprecedented in the paleoclimatic record, in furtherance of his dastardly fearmongering agenda. Wait- what’s that? Mann et al. actually found that around 1000 AD hurricane activity may actually have equaled and possibly exceeded that of today?!
But that doesn’t fit conveniently into my demonization of Mann or preconceived notions about the global climate conspiracy at all! No fair.
In all seriousness this is an interesting paper as despite some very serious caveats, it seems to indicate that we’ve got a decent grasp of the main drivers of hurricane activity for the region. Obviously it would be nice to increase the number of overwash records used, especially for the southeast US, the Gulf coast, and the Caribbean– for which we only have a single record per region.
The peak in medieval hurricanes is associated with persistent La Niña-like conditions in the Pacific and warmer tropical Atlantic SSTs– conditions that also notably produced a series of megadroughts in the US southwest and Mexico. Has anyone done comparisons between modern Atlantic hurricane activity and southwest drought conditions?