How robust is it?
Not very. Certainly nowhere near enough to base policy on it.
I was very impressed by Bakker’s intellectual integrity and courage in tackling this topic in the 11th hour of completing his Ph.D. thesis. I am further impressed by his thesis advisors and committee members for allowing/supporting this. Bakker notes many critical comments from his committee members. I checked the list of committee members, one name jumped out at me – Arthur Petersen – who is a philosopher of science that has written about climate models. I suspect that the criticisms were more focused on strengthening the arguments, rather than ‘alarm’ over an essay that criticizes climate models. Kudos to the KNMI.
I seriously doubt that such a thesis would be possible in an atmospheric/oceanic/climate science department in the U.S. – whether the student would dare to tackle this, whether a faculty member would agree to supervise this, and whether a committee would ‘pass’ the thesis.
Epistemic closure.
[Update a few minutes later]
The alarming thing about climate alarmism:
In short, climate change is not worse than we thought. Some indicators are worse, but some are better. That doesn’t mean global warming is not a reality or not a problem. It definitely is. But the narrative that the world’s climate is changing from bad to worse is unhelpful alarmism, which prevents us from focusing on smart solutions.
A well-meaning environmentalist might argue that, because climate change is a reality, why not ramp up the rhetoric and focus on the bad news to make sure the public understands its importance. But isn’t that what has been done for the past 20 years? The public has been bombarded with dramatic headlines and apocalyptic photos of climate change and its consequences. Yet despite endless successions of climate summits, carbon emissions continue to rise, especially in rapidly developing countries like India, China and many African nations.
Because all of the hysteria, name calling and outright lies have appropriately destroyed their credibility.
I went with my daughter through part of the first IPCC report – we looked at the sea level rise predictions.
Interestingly, enough time had past that several of the predictions were close enough to call now. They were all completely off the mark, of course.
If I had more time, I’d like to go through all of the IPCC documents, and take every prediction that they make (normally found in graphs and tables), and compare them to reality. From what I saw in my brief view, I’d be surprised to see a single prediction that they got right.
And if all of any organization’s past predictions were wrong, it would take a LOT of evidence to convince me that they now have it right…
I’ve said it before and I’ll say it again, if a model doesn’t agree with reality, it isn’t reality that’s wrong.
That’s puzzling, I just had a look at the report, which covers SLR on pages 257 through 282, and the best estimate is 183mm rise from 1990 through to 2030, with an increasing rate of SLR over time, so the rise to 2015 looks like it’s damn near bang on.
My experience with these reports is that there are at least two sets of predictions in a given assessment report. Those found in the body of the reports, buried as in this case almost three hundred pages in, and the notorious “Summary for Policy Makers” (SPM). For example, the First Assessment Report rounded that estimate above up to 200 mm of sea level rise in its overall summary.
Meanwhile we’ve been experiencing, according to satellite, 3.3 +/- 0.4 mm of sea level rise between 1993 and 2009 (which apparently is little different from today’s rate of increase). Extending to the entire period 1990-2030, that’s 132 +/- 16 mm of sea level rise which is significantly short even on the high end of your 183 mm predicted sea level rise which in turn is short of the number cited in the SPM.
This sort of thing happens all the time with these assessment reports. The body of the reports gives moderately accurate predictions, though skewed up from actual trends. Then the SPM sexes them up with an even higher error bar on the high side.
It’s not the rate of rise, it’s the acceleration, of which there isn’t any.
You get no brownie points for projecting business as usual.
For some reason, “The seas are rising!” sounds scarier to many (and thus more useful for propaganda) than “The seas are rising, just like they have been for 14,000 years!”.
It’s also a good idea to bear in mind that “sea level” no longer means what it used to; they now “adjust” the sea level data for a “Glacial isostatic adjustment”, further muddying the waters.
What the above means is that they believe that, due to land rising in the post glacial era (the last 14k years, since the departure of the ice sheets) the ocean basins are getting bigger. What this means in practice is that even if sea levels stay exactly the same, they “adjust” them to show a .3MM rise per year (what they say is the increase in ocean basin volume due to land rising).
This “adjustment” was added a couple of years ago. I’m sure it was just totally coincidental that the “adjustment” was implemented at a time when actual sea level data was showing a declining, not increasing, rate of increase (and thus running counter to all their models).