Global mean sea level has been rising. From 1961 to
2003, the average rate of sea level rise was 1.8 ± 0.5
mm yr–1. For the 20th century, the average rate was 1.7 ± 0.5
mm yr–1, consistent with the TAR estimate of 1 to 2 mm yr–1.
There is high conﬁdence that the rate of sea level rise
has increased between the mid-19th and the mid-20th
centuries. Sea level change is highly non-uniform spatially,
and in some regions, rates are up to several times the
global mean rise, while in other regions sea level is falling.
There is evidence for an increase in the occurrence of
extreme high water worldwide related to storm surges, and
variations in extremes during this period are related to the
rise in mean sea level and variations in regional climate.
The rise in global mean sea level is accompanied by
considerable decadal variability. For the period 1993 to
2003, the rate of sea level rise is estimated from observations
with satellite altimetry as 3.1 ± 0.7 mm yr–1, signiﬁcantly
higher than the average rate. The tide gauge record indicates
that similar large rates have occurred in previous 10-year
periods since 1950. It is unknown whether the higher rate
in 1993 to 2003 is due to decadal variability or an increase
in the longer-term trend.
That last sentence is a classic. They avoided the obvious answer that the higher rate from 1993-2003 was due to using a different methodology to generate the numbers. The older measurements are from tide gauges, and the newer ones are from satellite altimetry.
They failed to mention that tide gauges don’t agree with the satellite altimetry. They failed to mention that we don’t see much if any increase in rates from tide gauge data. They failed to provide any justification for the switch. They failed to provide any evidence that tide gauges are less reliable now than they were in the last century. They failed to do any verification of the accuracy of altimetry measurements.
This is just another IPCC nature trick – switching measurement systems to create an increase where there is none.