"There is now evidence there is a distinctive upward trend in global sea surface temperatures, and this we can now see from measurements made from Envisat," Professor Llewellyn-Jones said.
Working like thermometers in the sky, a number of different satellite instruments measure SST on an ongoing basis, such as the AATSR aboard ESA's Envisat.
The AATSR instrument aboard Envisat and its predecessors, ATSR-1 and ATSR-2 on the ERS-1 and -2 satellites, has been providing researchers with a precise quantitative indication of the changes and variability associated with the climate system over the past 16 years.
"Thanks to a new archive of uniformly processed data from 1991 to the present day, which is due to be launched later this year, it will soon be possible to provide a definitive statement of the rate at which global temperatures have been changing and how the variability of our climate has been changing," Llewellyn-Jones said.
"The ATSR instrument produces data of unrivalled accuracy on account of its unique dual view of the Earth’s surface, whereby each part of the surface is viewed twice, through two different atmospheric paths," Llewellyn-Jones added. "This not only enables scientists to correct for the effects of dust and haze, which degrade measurements of surface temperature from space, but also enables scientists to derive new measurements of the actual dust and haze, which are needed by climate scientists."