Temperature rises appear to be consistent with projections made by the Intergovernmental Panel on Climate Change, but satellite measurements show sea levels are rising at a rate of 0.12 inches a year -- compared to the IPCC's best estimate of 0.07 inches a year -- they said.
The study, published in the journal Environmental Research Letters, involved an analysis of global temperatures and sea-level data during the past two decades, comparing them both to projections made in previous IPCC assessments.
The researchers found that while the overall warming trend at the moment is 0.28 degree Fahrenheit per decade, which closely follows the IPCC's projections, satellite measurements of sea levels show a different picture.
Findings such as these, the researchers said, are important for keeping track of how well past projections match the accumulating observational data, especially since projections made by the IPCC are increasingly being used in decision-making.
"This study shows once again that the IPCC is far from alarmist, but in fact has under-estimated the problem of climate change," said Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research.