Jo Nova yesterday had a post on the disappearing “Very Hot Days” graph from the BoM website (see below). Jo made the salient points that there is no meaningful trend across the 105 years record and the year with the most hot days was 1952 when emissions were a a near perfect 311 parts per million and the temperature 1 degree Celsius less than today (also below).
What surprised me was that the year with the fewest hot days was 2011 and the period from 1996 to 2015 had significantly fewer hot days (crude estimate around 20 or 8%) than the preceding 20 year period from 1976 to 1995, including four of the six lowest years for hot days in the whole 105 year record.
I look forward to the BoM explanation as to how the decline in “very hot days” during the “warmest decade on record” is evidence of global warming and not a pause. It will be interesting to see if this graph is reproduced using the ACCORN 2 data reconstruction to see what the changes are.
It will also be interesting to see if Australia experiences a hotter than average summer as the bureau is forecasting and if so whether its reporting of “very hot days” is put into any historical context either by the bureau or the mainstream media.
I won’t hold my breath however. In the Annual Climate Summary – 2011 (published in 2012) it states “The ten-year average for 2002–2011 was the equal-warmest ten-year period on record for Australia (0.52 °C above average).” Note that by starting in 2002 it conveniently misses 1999 and 2000 that were cooler years also and hence years with near record low”very hot days”.