A climate sceptic has said that it is now time to end the debate over whether global warming is real after the most definitive study into temperature data gathered by weather stations over the past half-century.

Professor Richard Muller, a physicist at the University of California, Berkeley, who has been an outspoken critic of the science underpinning global warming, said that there is little doubt in his mind the phenomenon of rising land temperatures is real. Over the past two years, he has chaired a group of scientists who have carried out an exhaustive analysis of more than 1.6 billion temperature recordings collected from more than 39,000 weather stations at land sites around the world.

The Berkeley Earth Surface Temperature (Best) study was set up to test the findings of other studies and was part-funded by US billionaire brothers Charles and David Koch.

"When we began our study, we felt that sceptics had raised legitimate issues, and we didn't know what we'd find. Our results turned out to be close to those published by prior groups. We think that means that those groups had truly been very careful in their work, despite their inability to convince some sceptics of that," Professor Muller said.