The Earth's surface really is getting warmer, a new analysis by a US scientific group set up in the wake of the "Climategate" affair has concluded.
The Berkeley Earth Project has used new methods and some new data, but finds the same warming trend seen by groups such as the UK Met Office and Nasa.
The project received funds from sources that back organisations lobbying against action on climate change.
"Climategate", in 2009, involved claims global warming had been exaggerated.
Emails of University of East Anglia (UEA) climate scientists were hacked, posted online and used by critics to allege manipulation of climate change data.
Fresh start
The Berkeley group says it has also found evidence that changing sea temperatures in the north Atlantic may be a major reason why the Earth's average temperature varies globally from year to year.
The project was established by University of California physics professor Richard Muller, who was concerned by claims that established teams of climate researchers had not been entirely open with their data.
He gathered a team of 10 scientists, mostly physicists, including such luminaries as Saul Perlmutter, winner of this year's Nobel Physics Prize for research showing the Universe's expansion is accelerating.
Funding came from a number of sources, including charitable foundations maintained by the Koch brothers, the billionaire US industrialists, who have also donated large sums to organisations lobbying against acceptance of man-made global warming.
"I was deeply concerned that the group [at UEA] had concealed discordant data," Prof Muller told BBC News.
"Science is best done when the problems with the analysis are candidly shared."
The group's work also examined claims from "sceptical" bloggers that temperature data from weather stations did not show a true global warming trend.
The claim was that many stations have registered warming because they are located in or near cities, and those cities have been growing - the urban heat island effect.
The Berkeley group found about 40,000 weather stations around the world whose output has been recorded and stored in digital form.
It developed a new way of analysing the data to plot the global temperature trend over land since 1800.
What came out was a graph remarkably similar to those produced by the world's three most important and established groups, whose work had been decried as unreliable and shoddy in climate sceptic circles.
