Satellite measurements of the Earth's "skin temperature" have confirmed that global warming is heating up the planet.
The infra-red sensitive system was used to record temperature trends from 2003 to 2017.
It showed a warming pattern consistent with other land-based measurements.
Dr Joel Susskind, from the American space agency Nasa's Goddard Space Flight Centre, said: "Both data sets demonstrate the Earth's surface has been warming globally over this period, and that 2016, 2017, and 2015 have been the warmest years in the instrumental record, in that order."
The satellite system, called Airs (Atmospheric Infra-Red Sounder), records temperature at the surface of the ocean, land and snow-covered regions.
Its findings were compared with station-based data from the Goddard Institute for Space Studies Surface Temperature Analysis.
The results are published in the journal Environmental Research Letters.
Co-author Dr Gavin Schmidt, also from the Goddard Institute, said: "Interestingly, our findings revealed that the surface-based datasets may be underestimating the temperature changes in the Arctic.
"This means the warming taking place at the poles may be happening more quickly than previously thought."
