A paper published today in the journal Paleoceanography adds to the overwhelming evidence published by over 950 scientists that the Medieval Warm Period (MWP) was as hot or hotter than the present, and contrary to the claims of Michael Mann, the MWP was a global -not local- phenomenon. The paper finds mean annual sea surface temperatures (SSTs) in the Gulf of Mexico during the MWP were similar to near-modern SSTs, and that the SSTs were significantly cooler than the present during the Little Ice Age. Modern global warming began well before industrialization as a natural recovery from the nadir of the Little Ice Age. By mere coincidence, the global thermometer record begins at the end of the Little Ice Age and reflects recovery from these unusually cold temperatures during the current interglacial.
Famous quote from Michael Mann: "...it would be nice to "contain" the putative 'MWP'," after which he used Mann-made statistics to produce the alarmist and thoroughly discredited hockey stick graph with the MWP "contained," flattened, and beaten to a pulp.
Merging late Holocene molecular organic and foraminiferal-based geochemical records of sea surface temperature in the Gulf of Mexico
Abstract: A molecular organic geochemical proxy (TEX86) for sea surface temperature (SST) is compared with a foraminifera-based SST proxy (Mg/Ca) in a decadal-resolution marine sedimentary record spanning the last 1000 years from the Gulf of Mexico. We assess the relative strengths of the organic and inorganic paleoceanographic techniques for reconstructing high-resolution SST variability during recent climate events, including the Little Ice Age (LIA) and the Medieval Warm Period (MWP). SST estimates based on the molecular organic proxy TEX86 show a similar magnitude and pattern of SST variability to foraminiferal Mg/Ca-SST estimates but with some important differences. For instance, both proxies show a cooling (1°C–2°C) of Gulf of Mexico SSTs during the LIA. During the MWP, however, Mg/Ca-SSTs are similar to near-modern SSTs, while TEX86 indicates SSTs that were cooler than modern. Using the respective SST calibrations for each proxy results in TEX86-SST estimates that are 2°C–4°C warmer than Mg/Ca-SST throughout the 1000 year record. We interpret the TEX86-SST as a summer-weighted SST signal from the upper mixed layer, whereas the Mg/Ca-SST better reflects the mean annual SST. Downcore differences in the SST estimates between the two proxies (ΔT = TEX86 − Mg/Ca) are interpreted in the context of varying seasonality and/or changing water column temperature gradients.