The latest of many “sceptic” claims about global warming is that sea level is falling. Satellite altimetry (measuring sea-surface heights from satellite radar systems) supposedly shows the steady rise of sea level has reversed. Well, no, sea level is rising faster than ever.
Up-to-date reputable data can be found at http://ibis.grdl.noaa.gov/SAT/SeaLevelRise/LSA_SLR_timeseries.php
Before 1990 sea level was rising at only 2 mm/year. The change can be seen in a plot by Stefan Rahmstorf, Potsdam Institute for Climate Impact Research http://www.sciencexpress.org / 1 February 2007 / Page 1 / 10.1126/science.1136843
In this plot the satellite data (blue) overlap the older tide-guage data (red). You can see they correspond. This is significant because the two data sources are subject to different sources of interference and have different global coverage, so if they are consistent is increases confidence that they are correct.
This plot also shows that the current rate of rise is at the top of the range of predictions of the Intergovernmental Panel on Climate Change (IPCC), whose projections are shown as dashed lines and the grey-shaded band. This is consistent with other evidence that the effects of global warming are accelerating, and are now happening faster, in some cases much faster, than projections made even a few years ago.
It is true sea level is falling in some areas relative to the local land level. This is usually because the land is actually rising, due to local tectonic forces or, in some cases, due to the loss of glacier ice on land which used to weigh it down more.
There are the usual claims that the scientists involved in producing the above plots don’t know how to do their job. If that were true, those who claim sea level is falling should be getting their work published in mainstream scientific journals. Of course there are the usual claims of a wicked conspiracy blocking publication of contrary views. Like most conspiracy theories, that is nonsense.