Some excerpts from the Beddington's letters to Lawson:
The significance of urbanisation on the global temperature record is not contested by the vast majority of climate scientists. Most stations are not affected by the urban heat island effect and there are well-established ways of taking the effect into account for stations that are (such as comparing temperatures on still and windy nights and excluding urban stations). I refer you to my previous response for further information on this issue.
I should clarify that I did not seek to defend the original hockey stick analysis; I am aware that there are issues and uncertainties associated with it.
...you suggested that scientists at CRU delayed the release of temperature data they held. I hope that I can clarify this by laying out the situation as I understand it. The majority of the data in the CRU dataset are derived from the same freely-available raw data sets used by NOAA and NASA. However, the CRU dataset was compiled with the aim of comprehensiveness and therefore also includes data derived from station data obtained directly from countries, institutions and scientists on the understanding that this would not be passed on.
It is true that global average temperature has remained roughly constant over the past decade, but this in no way undermines the evidence that greenhouse gases are causing warming
[In response to Lawson's suggestion that models didn't predict the slowdown in warming] It remains very difficult, however, to predict year to year changes caused by short-term, internal processes in the climate system such as ENSO – primarily because the climate system is chaotic.