This was sent in February 2010 when the furore over Climategate was still at its peak and before the inquiries got under way. It consists of a summary of the science of global warming sent to Beddington by Julia Slingo, the chief scientist at the Met Office. Slingo, you may remember, later appeared at the SciTech committee hearings alongside Beddington.
What is interesting about Slingo's take on climate science is all the statements of statistical significance she makes:
For the last 3 decades the rate of temperature increase is significant even when uncertainties in the observations are factored in (Fig. 3).
Every year since 1998 (in fact every single year for the past three decades) has been significantly warmer than the temperatures you'd expect if there was no warming [baseline of 1861-1900]. The last ten years have all been among the 15 warmest in the historical record ; it is just that these years have not been quite as warm as 1998.
From the 1980s onwards each decade has been significantly warmer than the previous decade.
The overwhelming majority of leading climate scientists agree on the fundamentals - that the Earth is definitely warming
As readers here know, the claims of statistical significance in the global temperature records are based on an assumption that the Earth's temperature can be approximated by the AR1 statistical model, an assumption that can apparently be readily shown to be incorrect. As Doug Keenan points out in an email, Slingo's final claim - that the overwhelming majority of leading climate scientists agree that the Earth is definitely warming - is 'technically true, but irrelevant if none of those scientists knows how to determine whether such warming is significant'.
What is so frustrating about this is that the question of model selection for the temperature records doesn't appear to be a particularly abstruse bit of statistics, as this excerpt from an undergraduate textbook on time series analysis shows (see also here):
So I must confess that I am a little mystified as to why the AR1 assumption is made. Nobody seems willing to say anything in favour of it, but nobody within the climate science or statistical mainstream seems willing to say it's wrong.