Stress—this is a rumor. However, the rumor says that next week Richard Muller will release the latest Berkeley Earth Surface Temperature analysis of surface temperature data going back as far as the 18th century. Muller, once skeptical of the temperature records that showed considerable global warming in recent decades, set up BEST to reanalyze that data. In 2011, BEST's preliminary analysis of land temperature data found:
….a warming trend that is shown in the figure [below]. It is very similar to that reported by the prior groups: a rise of about 0.7 degrees C since 1957. (Please keep in mind that the Berkeley Earth curve, in black, does not include adjustments designed to eliminate systematic bias.)
The Berkeley Earth agreement with the prior analysis surprised us, since our preliminary results don't yet address many of the known biases. When they do, it is possible that the corrections could bring our current agreement into disagreement.
The rumors say that new BEST reanalysis will show that global average temperature has increased by 1.5 degrees Celsius since pre-industrial times and will suggest that most of the warming since the 1950s is the result of increased greenhouse gas concentrations in the atmosphere.
I will report back if and when these rumors are confirmed.