Present day sea-level rise is a major indicator of climate change. Since the early 1990s, sea level rose at a mean rate of 3.1mm/yr. However, over the last decade a slowdown of this rate, of about 30 per cent, has been recorded. It coincides with a plateau in Earth's mean surface temperature evolution, known as the recent pause in warming. Here we present an analysis based on sea-level data from the altimetry record of the past 20 years that separates interannual natural variability in sea level from the longer-term change probably related to anthropogenic global warming. The most prominent signature in the global mean sea level interannual variability is caused by El Nino-Southern Oscillation, through its impact on the global water cycle. We find that when correcting for interannual variability, the past decade's slowdown of global sea mean sea level dissapears, leading to a similar rate of sea-level rise (of 3.3+/- 0.4 mm/yr) during the first and second decade of the altimetry era. Our results confirm the need for quantifying and further removing from the climate records the short-term natural climate variability if one wants to extract the global warming signal.
The rate of sea-level rise by Anny Cazenave, Habib-Boubacar Dieng, Benoit Meyssignac, Karina von Schuckmann, Bertrand Decharme and Etienne Berthier published in Nature Climate Change online on 23 March 2014. DOI: 10.1038/NCLIMATE2159.
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