HADCRUT5 – nothing more malleable than data in Climate ‘Science’.

Mean Global Temperature is calculated by a number of National Agencies and Universities with the most prominent being BEST, GISS and HADCRUT. HADCRUT is a collaboration of the UK Met Office and the Climate Research Unit at the University of East Anglia. Global data is used as a basis of a model of mean global temperature which is published monthly. These data use so called ‘anomalies’ of temperature, rather than the more accurate term deviations, as an anomaly is an outlier from the variability within the dataset. It is a carefully chosen trigger word to fuel the alarmist view of weather and hence climate. The data used in the models of global temperature are secondary data, relying on already averaged temperatures, and these are further processed, creating figures which are are 4th of 5th level abstractions from the primary data. It is claimed that ‘means are easier to deal with’ but at each level of abstraction vital information is lost as to the internal variability of the measurements, as at each step variance is set to zero.

There is much to critique about these models, not least that they are combining data from independent populations ie climatic regions without accounting for heteroscedasticity, but they are the best we have. However they are subject to constant revisions and it is fascinating how malleable the past is when it comes to each revision. A simple scientist might think that the past temperatures, once calculated, are fixed, but it constantly changes within these models, making analysis very difficult.

Traditionally HADCRUT has produced temperatures lower than the other two surface temperature based models, but this failure to adhere to ‘The Cause’ has now been corrected.

The latest incarnation of HADCRUT is version 5, which is standard from January 2022. It is possible to compare earlier versions ie 3 & 4.

If we subtract the each version from the current one we find an interesting picture.

Adjustments between versions 3 and 4 appear minor, but HADCRUT5 has produced a major change.

with significant annual and decadal implications.

and significantly warming the present, more so than even the change from version 3 to 4 had managed.

This much warmer present is more in keeping with the Global Warming alarmism.

The overall changes in the Mean Global Temperature has been:

Years	HADCRUT3 to 4	HADCRUT 4 to 5
1850-1959	0.00 oC	-0.41 oC
1960-2021	+0.03 oC	+0.56 oC

Cool the past, warm the present, Global Warming is worse than we thought. It is anthropogenic, within the models of the Climate ‘Scientist’, more activist than scientist.