8 January 2013 Last updated at 10:17 ET
By David Shukman Science editor, BBC News
The Met Office says its long-term projections forecast significant warming
The UK Met Office has revised one of its forecasts for how much the world may warm in the next few years.
It says that the average temperature is likely to rise by 0.43 C by 2017 – as opposed to an earlier forecast that suggested a warming of 0.54C.
The explanation is that a new kind of computer model using different parameters has been used.
The Met Office stresses that the work is experimental and that it still stands by its longer-term projections.