Quartz
March 30, 2009, 8:59am
1
I’ve read the Telegraph’s article on sea level rises which says it’s a load of bunkum. Now the author’s (and the paper’s) proclivities are well-known and he depends upon the work of one Professor Nils-Axel Mörner, who apparently believes in dowsing. :rolleyes: :dubious: So you can imagine my suspicion above and beyond my usual scepticism. However, the article makes one particular claim which should be verifiable, but my search-fu isn’t good enough:
One of his most shocking discoveries was why the IPCC has been able to show sea levels rising by 2.3mm a year. Until 2003, even its own satellite-based evidence showed no upward trend. But suddenly the graph tilted upwards because the IPCC’s favoured experts had drawn on the finding of a single tide-gauge in Hong Kong harbour showing a 2.3mm rise. The entire global sea-level projection was then adjusted upwards by a “corrective factor” of 2.3mm, because, as the IPCC scientists admitted, they “needed to show a trend”
One single gauge?
Let’s keep this GQ, please. Is the bit I’ve quoted true or false?
Here is a report on Sea Level Rise as measured by tidal gauges. It shows several hundred gauges used to create the average rise.
It seems the author also ignored satellite data, and it was not only one gauge being used:
High quality measurements of (near)-global sea level have been made since late 1992 by satellite altimeters, in particular, TOPEX/Poseidon (launched August, 1992) and Jason-1 (launched December, 2001). This data has shown a more-or-less steady increase in Global Mean Sea Level (GMSL) of around 3.3 ± 0.4 mm/year over that period. This is more than 50% larger than the average value over the 20th century.
Recent observations show the observed sea levels from tide gauges (blue) and satellites (red) are tracking near the upper bound (black line) of the IPCC 2001 projections (grey shading and black lines) since the start of the projections in 1990 (Rahmstorf et al. 2007). This upper limit leads to a global-averaged sea-level rise by 2100 of 88 cm compared to 1990 values. These observations do not necessarily indicate that sea level will continue to track this upper limit - it may diverge above or below this upper limit. However, the ice sheet uncertainties referred to above are essentially one-sided – i.e. they could lead to a significantly larger sea-level rise than current projections but are unlikely to lead to a significantly smaller rise. Note also that greenhouse gas emissions are now tracking just above the highest of the SRES emission scenarios used in calculating these projections (GCP_CarbonBudget 2007, Raupach et al. 2007; Canadell et al. 2007).
The bad news is that so far the rise is matching the **upper **limits of the projections.
Quartz
March 30, 2009, 2:47pm
4
Right. So the “sea level isn’t rising” bit is a load of cobblers, then. Thank you. But what about the charge against the IPCC? I expect it’s false too, but it would be nice to nail it.