The rate at which the global oceans have risen in the past two decades is more significant than previously recognised, say US-based scientists.
Their reassessment of tide gauge data from 1900-1990 found that the world’s seas went up more slowly than earlier estimates – by about 1.2mm per year.
But this makes the 3mm per year tracked by satellites since 1990 a much bigger trend change as a consequence.
It could mean some projections for future rises having to be revisited.
“Our estimates from 1993 to 2010 agree with [the prior] estimates from modern tide gauges and satellite altimetry, within the bounds of uncertainty. But that means that the acceleration into the last two decades is far worse than previously thought,” said Dr Carling Hay from Harvard University in Cambridge, Massachusetts.
“This new acceleration is about 25% higher than previous estimates,” she told BBC News.
Dr Hay and colleagues report their re-analysis in this week’s edition of the journal Nature.
