"The interannual and decadal variability in Clipperton coral...demonstrates strong coherence to the [natural] Pacific Decadal Oscillation and the El Niño/Southern Oscillation (ENSO) with reduced ENSO variability from 1920 to late 1930s and enhanced variability in the late twentieth century."The reconstruction is also compared to instrumental sea surface temperature observations [most of which were made with crude measurement methods and questionable adjustments] which show warming of 0.5C-0.75C over the same time-frame, potentially indicating an upward bias of man-made observations in comparison to a uniform proxy temperature reconstruction. Where have we seen that before?
|Top graph is the coral proxy temperature reconstruction, with added red horizontal line to show temperatures were approximately the same around 1930 as at the end of the record, and only ~0.25 warmer than in ~1885. Second graph shows 2 instrumental records, which do have issues.|