Each monthly update of V4C (corrected) changes past results as well as adding the new monthly temperatures. This is due to their homogenisation algorithm. I had already noticed that V4 gave warmer results than V3 but found that the uncorrected data agree where stations overlap.
This means that the expectation value for the temperature difference between two nearby stations is changing with time. This then affects any “adjustments” made to current and past measured values by assuming these stations always move in temperature synchronously. The end result seems to maintain warming trends. Here is a comparison of V4C and V4U.
Comparison of monthly temperature anomalies for V4C and V4U
There is also a significant difference between V4C and V4U since 2015 in the annual temperature values.
Comparison of annual global temperatures for V4 Corrected and Uncorrected
Nick Stokes uses the unadjusted data for TempLS. I am tempted to do the same or at least calculate both to get an estimate of uncertainties. There is a significant difference between the two in recent months.
My calculation of the global temperature anomaly is based on GHCN V4 and HadSST3 using a 3D spherical triangulation method and a baseline of 1961-1990. The value for August 2020 is 0.82C. Interestingly though GHCN V4 is forever updating older temperatures due to its homogenisation algorithm. So July’s temperature has also risen in value from 0.79C to 0.83C. Here is the monthly series.
Monthly temperature for August 2020. Purple shows last month’s values. Note the increase for July.
The spatial distribution shows a cooler southern hemisphere.
The annual average for the first 8 months of 2020 is 0.93C which while slowly reducing is still higher than 2016. The August estimate is 0.02C cooler than that made in July despite the slight increase for the July monthly value.
Annual Temperature Anomalies (first 8 months 2020)
I have been back living in Italy since the end of August. I worked here for over 20 years. There is something special about Italy that still makes me feel at home ( the food & wine ?). I was also quite prepared for the UK to impose a 14 day quarantine on returning to the UK at the end of September. However, since then the relative infection rates seem to have inverted and the UK is now way surpassing the infection rate of Italy.
ECDC 7 day Covid infection rates per 100,000 population
UK infection rates are now nearly double those of Italy!
I think part of the reason for this is that Italians suffered the worst death rate in Europe during the early months of 2020 because people were meeting inside. Outside in summer the risk of infection is tiny. Even Italians were spooked early into extreme social distancing ! Although apparently Berlusconi ignored government advice during his stay in Sardinia .
Despite all this he seems to be recovering fine despite getting COVID at age 83!