Remember the warm period in the Middle Ages just before the Little Ice Age? Michael Mann and associates tried to erase it from the record. The hockey stick illusion was headline news for the IPCC in 2001 and now it is discreetly parked in the archives and Mann has become an embarrassment to his colleagues.
A thought-provoking piece on deep ocean temperatures has turned up and the following is some of the explanatory commentary provided on Watts Up With That.
This exposes the ubiquitous trick of the Climate Debate, in which Global Temperatures are [almost] always shown only from the depths of the Little Ice Age (clearly marked on the first graph by Gebbie), resulting in images similar to Gebbie’s Figure 2 — despite the fact that most 2 millennia reconstructions clearly show the Roman and Medieval Warm Periods as generally in the same range as the Modern Warm Period. Given the acknowledged range of error in any temperature reconstruction and in modern estimates of global surface temperatures (today, in absolute temperatrures, around +/- 0.5ºC or a range of 1ºC) — there may be little, if any, significant-to-the-global-environment difference between the two periods.
The Medieval Warm period did not result in a “Climate Catastrophe” and the [iffy] little additional 0.2°C seen today is very unlikely to spark a modern Climate Catastrophe either.
A great deal of the polarization in the Climate Debate is based on this little trick of data presentation — using a starting date known to represent a low point in some data set of a measurement which the author wishes to show has increased to a present high. Failure to show the full context of the data is a type of data falsification.