The Met Office’s method of predicting the annual increase in global average temperature may have a “warm bias”, according to a BBC weather forecaster.
Paul Hudson said that the yearly headline predictions made by the Met Office had been “too warm” for 13 of the 14 years so far this century.
In December 2012, the Met Office gave a “best estimate” based on computer models that the global temperature would be 0.57C warmer than the 1961-1990 average of 14C.
Last month, it said that a “central estimate” of real measurements up to the end of October showed an increase of 0.49C in 2013.
While the difference is small, Mr Hudson, who spent 15 years working for the Met Office, noted in a blog that the incorrect predictions this century “have all been on the warm side and none has been too cold”.
He acknowledged that the Met Office had included a range of temperature increases in its predictions and that the observed increases fell within this margin of error.
Mr Hudson wrote: “The Met Office believe one of the reasons for this ‘warm bias’ in their annual global projections is the lack of observational data in the Arctic Circle, which has been the fastest warming area on Earth.
“They also suggest that another reason why the global surface temperature is falling short of their projections is because some of the heat is actually being absorbed in the ocean beneath the surface.”
A Met Office spokeswoman said: “As Paul says, there is evidence that incomplete global coverage of the available temperature observations may have led to an under-representation of regions that were unusually warm.”
A leading climate sceptic scientist told MPs yesterday that “doing nothing for 50 years” about climate change would be better than present policies which seek to cut emissions.
Richard Lindzen, a former professor of meteorology at Massachusetts Institute of Technology, believes that climate change poses no risk to mankind and insists that there is no consensus that sea levels are rising.
He told the Commons Energy and Climate Change Committee: “Whatever the UK is deciding to do vis-a-vis climate will have no impact on your climate. It will have a profound impact on your economy.