The reality? 11 mm or less over the last 2 decades!
The article claims 11 mm of water solely from melting ice sheets. It says the total increase was five times larger than that.
The increase over the last 19.5 years, 1993 to mid-2012, was between 53-68 mm. The average rate was 3.1 mm/year +/- 0.4.
http://sealevel.colorado.edu/content/2012rel4-global-mean-se...
The original IPCC report on global warming predicted an average rate of global mean sea level rise of about 6 cm per decade.
IPCC AR1 did not predict 6 cm/decade rate for this time; it predicted 6 cm/decade averaged over the century 2000-2100, starting slowly and then accelerating. (Rising CO2 levels accelerate melting; economic growth accelerates CO2 rise).
If you look at AR1's actual forecast,
What it predicted for the near-term, 1990-2010 was (eyeballing the graph): a 9 cm rise, lower range 5 cm, upper range 14 cm. A rate of 2.5-7 mm/year.
The graph is from page 277.
http://www.ipcc.ch/ipccreports/far/wg_I/ipcc_far_wg_I_chapte...
1) sea level rises have always been one of the trickier predictions to make, and the IPCC has never been cagey about this. It's subject to a large number of secondary and tertiary feedbacks, which can cause huge variances in what the models say, and should not be a proxy for how correct models from the 80s and 90s were. Notice that the Wikipedia article actually summarizes the report as saying "6 cm per decade over the next century (with an uncertainty range of 3 – 10 cm per decade)". In other words, there is a lot of variability here, but the best guess (22 years ago...think of the kinds of computers those models were running on) was that the average rise over the next century would be 6cm per decade.
This is quite different than the current article, which is of course about actual measurements and what they mean for the models, which is presumably exactly the kind of verification (one way or the other) that we should be looking for. If the models were wrong (as undoubtedly some were since there are a number of different models and we have to try to reconcile them) then we can go back and figure out why our models were wrong; not throw the baby out with the bathwater.
2) according to your claim, the reality was 11mm (or less) over the last two decades, "over a factor of 100 miss". Now, I'm an American and the metric system confuses me, but isn't half of 11mm 5.5mm, which is .55cm, which would only be a factor of 10 off from 6cm?
3) According to current data (check here[1] for sources and raw data), the sea level actually rose 3.1mm per year from 1993 to 2003. I don't know where you got your 11mm for the last two decades, but the reality adds up to 3.1cm over that decade, only a factor of two off and well within the prediction from 1990, which has of course been supplanted by several reports since then.
The last IPCC assessment even explicitly stated that they can't be certain if the acceleration of sea level rise seen in the last two decades can be expected to continue or if other dynamics will become dominant, as they don't have enough data (for the current trend) and their models might not be sophisticated enough yet. Their best guess in 2007 was 18 to 59cm by 2100, but I believe that's been revised since then.
Hey, what do you know: scientists being scientists. If you actually take time to take a look, they include their confidence intervals every time.
[1] http://www.climatewatch.noaa.gov/article/2009/climate-change...
citation: http://people.iarc.uaf.edu/~sakasofu/pdf/two_natural_compone...
We would unquestionably have cleaner air if we shut down all coal-fired generating plants and banned the internal combustion engine tomorrow. There are excellent reasons to do just that, environmentally speaking. But does it sound like a good idea to you? If so, then you may need to think things through a little farther, I believe.