“…since records began in 1659”

The year 1659 appears with remarkable frequency in the media in 
connection with the English climate, often in the form “since records 
began in 1659”. It is a statement  rarely if every questioned by 
anyone with access to the mainstream media. 

Just pause and think about that claim. Does it seem probable that 
official weather records have been meticulously kept for three and a 
half centuries, kept before the scientific and industrial revolutions, 
kept before the English or British state became a bureaucratic monster? 
The answer of course is that it is extremely improbable  and did not 
happen. What did happen in the third quarter of the last century is that 
a British meteorologist by the name of  Gordon Manley attempted to 
produce an historical series  for temperature in England which he 
eventually extended to 1659. His work over a quarter of a century is 
summarised in two papers published by the Royal Meteorological Society: 
The mean temperature of central England 1698-1952 (1953) and Central 
England temperatures – monthly means 1959-1973 (1974) The two papers 
can be found at  http://www.rmets.org/publication/classics/cp1.php Other 
academics have built on his work since. 

Manley, like a good academic, was scrupulous in admitting the 
difficulties in constructing such an historical series: “Methods of 
approximation must be resorted to [when constructing any historical 
series],  most notably in England where, despite our very long 
scientific tradition, almost all observation before 1841  was dependant 
on amateur effort so that widely scattered records of diverse length and 
accuracy provide endless problems… The English records offer a 
formidable problem”. The opening paragraph of  his 1953 paper. 

“Formidable problem” is understating matters. Even readings of 
temperature today using highly sophisticated equipment  cause 
considerable dispute because where the measurement is taken is all 
important, for example,  readings taken in or close to urban  areas will 
produce a higher temperature than ones taken in areas with little or no 
human habitation. Trying to get a consistent environment to take 
temperature over a long period of time is obviously difficult and 
comparisons with the past questionable because we can never know what 
the conditions were exactly at any point in the past.  Hence, even with 
the advent of official records early in Victoria’s reign it is not 
simply a question of comparing data from one time with another. For 
example, has can temperatures in London today be meaningfully compared 
with those of 150 years ago when there were no motorised vehicles and 
coal was the main energy source? 

Once Manley enters the period before the official records (pre 1841) his 
caveats  become ever more severe, whether it be the paucity of the data, 
breaks in the data, the widely different means used to collect data, the 
absence of any information about how data was collected and even the 
switch between the Julian to the Gregorian calendar in 1752 which means 
every record prior to the change has to be recalibrated to the 
Gregorian. 

Manley’s research and analysis was honest but the most rational thing 
to conclude from it is that it proved no meaningful  historical 
temperature series  for England could be constructed over the period. 
Yet his research is trotted out as having the status of certain fact by 
the mainstream media, politicians and, to their shame, often  by 
scientists when they enter the realm of public debate.