Read here. Map source. The Mannian style of climate science was established to fabricate a scenario that the Medieval Warming (MWP) and Little Ice Age (LIA) periods were insignificant weather blips, primarily felt in the northern Atlantic/European region. A vast amount of both anecdotal and paleo-climate empirical evidence refutes Mann's contentions that the MWP and LIA were insignificant and only regional. Another peer reviewed study adds to the refutation.
Researchers Rivera et al. determined that the current terminus position of the Chilean glacier Jorge Montt is the same as the terminus position prior to the onset of the LIA, some 450 years before present (~1550 AD). Dendrochronology analysis established that the maximum extent of the glacier was achieved around 1750 AD.
"A team of scientists studied tree rings...recently exposed by the retreating Patagonian glaciers....trees were dated using radiocarbon methods, yielding burial ages between 460 and 250 years ago...study confirms that the Little Ice Age existed in Chile too. Now remember how the high-sticking hockey team kept trying to have us believe that the Medieval Warm Period-Little Ice Age thing was a local phenomena, and not global?...No misprint there. It’s correct. Before the LIA the Chilean glaciers were at the same spot as the present position. Send a copy of that paper to Michael Mann..." [A. Rivera, M. Koppes, C. Bravo, J. C. Aravena 2011: Climate of the Past]