Climate change emails row deepens

And it continues:

SPECIAL INVESTIGATION: Mail Online

The claim was both simple and terrifying: that temperatures on planet Earth are now ‘likely the highest in at least the past 1,300 years’.

As its authors from the United Nations Intergovernmental Panel on Climate Change (IPCC) must have expected, it made headlines around the world.

Yet some of the scientists who helped to draft it, The Mail on Sunday can reveal, harboured uncomfortable doubts.

In the words of one, David Rind from the US space agency Nasa, it ‘looks like there were years around 1000AD that could have been just as warm’.

Keith Briffa from the University of East Anglia’s Climatic Research Unit (CRU), which plays a key role in forming IPCC assessments, urged caution, warning that when it came to historical climate records, there was no new data, only the ‘same old evidence’ that had been around for years.

‘Let us not try to over-egg the pudding,’ he wrote in an email to an IPCC colleague in September 2006.

‘True, there have been many different techniques used to aggregate and scale data - but the efficacy of these is still far from established.’

But when the ‘warmest for 1,300 years’ claim was published in 2007 in the IPCC’s fourth report, the doubters kept silent.

It is only now that their concerns have started to emerge from the thousands of pages of ‘Warmergate’ emails leaked last month from the CRU’s computers, along with references to performing a ‘trick’ to ‘hide’ temperature decline and instructions to resist all efforts by the CRU’s critics to use the Freedom of Information Act to check the unit’s data and conclusions.