© Getty ImagesLord Lawson's Global Warming Policy Foundation say the Met Office's predictions are biased
A report for a think tank led by former Tory chancellor Lord Lawson says a computer programme behind figures that shape climate change policy is biased in favour of higher temperatures.
Large sums of public and private sector money could be 'malinvested' in everything from wind farms to heat-proof road surfaces as a result, it claims.
Lord Lawson, chairman of the Global Warming Policy Foundation, said: 'The Government's policy of abandoning cheap conventional energy and moving to expensive (and unreliable) renewable energy has always been of dubious merit.
'The fact that it now emerges this policy has been based on projections by a computer model which has been found to be fatally flawed means that an independent expert review of the model and its projections is both essential and urgent.'
The claim, hotly disputed by the Met Office, comes as scientists and officials meet in Stockholm to finalise a major report by the United Nations' Intergovernmental Panel on Climate Change.
Experts claim the think tank timed its report to undermine the IPCC, which is expected to say the case for man-made global warming is stronger than ever.
The report attacks HadCM3, a programme used to predict the effect of carbon dioxide levels.
It says there is a glitch in the way it factors in the impact of low-lying cloud, with estimates of small temperature rises adjusted upwards. Report author Andrew Montford said: 'The UK's official climate predictions are therefore unreliable and excessively alarmist.
'The problem is highly technical but its implications are that the model, as currently used, will always provide high estimates of future warming.'
However, the Met Office said it is confident in HadCM3. It said it uses data from many models, and the figures are independently reviewed.
Bob Ward, a climate change expert at the London School of Economics, said: 'This is a political stunt by Lord Lawson's Global Warming Policy Foundation to try to distract attention from the IPCC report.
'The Met Office climate model is based on the best available scientific evidence and expert judgment.'
Drafts of the IPCC report - the first in six years - say it is at least 95 per cent certain human activity is the main cause of temperature rises since the 1950s. That is up from 90 per cent in 2007, and 66 per cent in 2001.
The assessment will be used by governments worldwide to set policy.
Arctic sea ice extent (polar) bears little relationship to global mean temperatures but was used by the warmists to support their arguments for a globalist agenda. The skeptics have gleefully taken this up and realising from historical records that the arctic ice would return as it always has done have flung this back at them in a dramatically successfull way. This key if somewhat flakey indicator is persuasive to the political class, who wouldn't know a thermometer from a plate of egg and fries, is having a disproportioante effect on their self preservation systems. Unfortunately they will not react effectively until it is (was) all too late to prepare for the dramatic period of global cooling which is alreadt underway.
I just hope it does not precipitate a full blown glaciation.