This is what is laughable. The original IPCC report on global warming predicted an average rate of global mean sea level rise of about 6 cm per decade. The reality? 11 mm or less over the last 2 decades! That's over a factor of 100 miss. Nobody seems to notice how the goal posts on this issue are constantly moving. In the end, yes, there is global warming, but it is not even close to what was predicted in the late 1980s and early 1990s.
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).
Also ignored is the linear warming trend that started before the large industrial production of CO2 and that accounts for significant amounts of warming. And the multi-decadal pacific oscillation. But you know, alarmism sells.
And I, in turn, have never understood the argument you mention. Regulations have effects, both malevolent and benign. When regulations are enforced, someone wins, someone else loses. If we "clean up the air and breathe easier" as you put, it but millions of people end up in poverty (or worse), is that a net win?
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.
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.
http://en.wikipedia.org/wiki/IPCC_First_Assessment_Report