> this period is too short to determine meaningful changes in the rate of rise
Now, you note that the authors openly acknowledge that the rate of rise is measured in low-single-digit units of millimeters per year. So, why is the y-axis of Figure 2 measured in centimeters?
Hint: it’s because every point on that plot is a wild extrapolation.
This paper is not good, btw. The fact that it’s “only three pages” should be a blinking red sign telling you that it is not serious. Just read the more recent IPCC reports, because they deal with the question of updates from prior reports.
I don't understand, or do not spot the issue you are seeing. Could you expand a bit?
The uncertainty on the rate of change is quite large (relatively), therefore, any 100 year projection has huge, compounded uncertainty. Figure 2 is not useful for determining anything about the present.
Quoting "The satellite-based linear trend 1993–2011 is 3.2± 0.5 mm yr−1 , which is 60% faster than the best IPCC estimate of 2.0 mm yr−1 for the same interval"
But, as the authors point out, the worst case forecasts that were within-data, are so for the wrong reasons. Quote "The model(s) defining the upper 95-percentile might not get the right answer for the right reasons, but possibly by overestimating past temperature rise."
My previous comment is regarding Figure 2, i.e. "Sea Level". I would invite you to read the whole paper. It is only 3 pages and written without jargon.