Chapter excerpt Michael Mann’s Hockey Schtick: From best-selling The Politically Incorrect Guide to Climate Change by Marc Morano
But Overpeck is on record denying the reality of the Medieval Warm Period. In 1999, he declared, “Now, high-resolution paleoclimate records stretching back 1,200 years confirm that the so-called Medieval Warm Period did not exist in the form of a globally synchronous period as warm, or warmer, than today.” He was frustrated by the Medieval Warm Period’s impact on the climate change debate, as a 2005 email from him, exposed in Climategate, revealed: “I’m not the only one who would like to deal a mortal blow to the misuse of supposed warm period terms and myths in the literature.”9
But despite Overpeck’s claims and what was implied by Mann’s infamous hockey stick, the Medieval Warm Period—also called the Medieval Climate Optimum—is not a myth. The most recent research clearly shows that it was real—and was in fact global, not just confined to the Northern Hemisphere. The Center for the Study of Carbon Dioxide and Global Change reported in 2017 that “the Medieval Warm Period was: (1) global in extent, (2) at least as warm as, but likely even warmer than, the Current Warm Period, and (3) of a duration significantly longer than that of the Current Warm Period to date.”10
And as the Science and Public Policy Institute reported in 2009, “More than 700 scientists from 400 institutions in 40 countries have contributed peer-reviewed papers providing evidence that the Medieval Warm Period (MWP) was real, global, and warmer than the present. And the numbers grow larger daily.”11
A 2003 study by researchers from the Harvard-Smithsonian Center for Astrophysics, using more than two hundred paleoclimate studies from all over the planet, confirmed the existence of the MWP and LIA and found that twentieth-century warming was not unprecedented.12
A 2012 peer-reviewed study established medieval warming on the tropi- cal island of New Caledonia in the Southern Hemisphere.13 And a 2012 study published in the Geophysical Research Letters found that the subsequent