Comment from Professor Phil Jones, Director of the Climatic Research Unit:
The following email, which I can confirm is genuine, has caused a great deal of ill-informed comment, but has been taken completely out of context and I want to put the record straight. "I've just completed Mike's Nature trick of adding in the real temps to each series for the last 20 years (ie from 1981 onwards) amd from 1961 for Keith's to hide the decline. Mike's series got the annual land and marine values while the other two got April-Sept for NH land N of 20N. The latter two are real for 1999, while the estimate for 1999 for NH combined is +0.44C wrt 61-90. The Global estimate for 1999 with data through Oct +is 0.35C cf. 0.57 for 1998."
The first thing to point out is that this refers to one diagram - not a scientific paper - which was used in the World Meteorological Organisation's statement on the status of the global climate in 1999 (WMO-no.913). The diagram consisted of three curves showing 50-year average temperature variations for the last 1000 years. Each curve referred to a scientific paper and a key gives their details. Climate records consist of actual temperature records from the mid-19th century and proxy data (tree rings, coral, ice cores, etc) which go back much further. The green curve on the diagram included proxy data up to 1960 but only actual temperatures from 1961 onwards. This is what is being discussed in the email. The word 'trick' was used here colloquially as in a clever thing to do. It is ludicrous to suggest that it refers to anything untoward.