Previously, Tom Fuller demonstrated why he isn’t a serious journalist by making a fool of himself on the issue of polar bears.Today, Fuller mixes it up with a little sea level rise (SLR) malarkey. I do love the little “Reality Wikipedia has a liberal climate alarmist bias” preface:
Wikipedia, which doesn’t always play fair when climate issues are discussed, has the chart everyone needs to see to provide perspective on sea level rise. Titled ‘Post Glacial Sea Level Rise, it shows a dramatic rise in sea levels that stopped dead 6,000 years ago and a very flat line since. You could balance a glass of water on the last 6,000 years of that graph.
So what? This means nothing without looking at the drivers of SLR over the same period. Assuming the best of Fuller and choosing to believe that he isn’t trying to be deliberately misleading, this is just a shocking demonstration of laziness or ignorance. SLR doesn’t just magically happen. The clear implication of Fuller’s reference in light of the rest of the post is: “SLR has basically flatlined since we melted out of the Last Glacial Maximum- what’s the big deal?” Of course, the big deal is that radiative forcing isn’t (and certainly won’t in the near future be) flat enough to “balance a glass of water on”. There is no reason to expect SLR to be either.
This hasn’t stopped the marketing gurus from trying to play to our ancestral horror stories and modern fears of flooding. Because there’s still enough ice left in Antarctica and Greenland to cause dramatic sea level rises, all they have to do is say that global warming will melt that ice and we’re in trouble. And so they do.
Fuller would have us believe that there is no actual basis for concern that the WAIS and GrIS could contribute to dramatic sea level rise. Any such claims are “hype” and not science:
Again, we are forced to separate the hype from the science. Remember that the IPCC projects sea level rise this century of 18-59 cm, unless dramatic loss of Greenland and/or Antarctic ice occurs. That’s from their AR4 report.
This isn’t actually what the AR4 says, though it’s not as screamingly wrong as some of Fuller’s other claims. The 18-59 cm range excludes any contribution from the GrIS and WAIS above the observed rate during 1993-2003. It doesn’t even assume a linear increase in their contribution alongside temperature increase- something that would increase the upper bound to 0.8m all by itself.
From the minute that AR4 was published, a string of papers, conferences, publicity events (such as parliamentary cabinet meetings held underwater) have been screaming from the headlines and news reports, drumming into us the message that dramatic loss of Greenland and/or Antarctic ice will in fact occur.
The audacity of researchers to continue working after the AR4! How dare they try to reduce the acknowledged uncertainty with regard to SLR by having conferences and publishing papers (a string of them even)? Have they no shame at all? And who do they think they’re fooling saying “that dramatic loss of Greenland and/or Antarctic ice will in fact occur”? Because this wasn’t explicitly included in the AR4 projections, we know that it can’t possibly occur- Q.E.D., no take-backs. Jeez!
Climate theory predicts that increased precipitation in the much larger middle of these ice caps will be in the form of snow, which will turn into ice and counterbalance some, most or all of the melt around the edges.
The “most or all” part is obviously where Fuller gets into trouble. This is a claim that he has made and failed to back up over at Michael Tobis’s, because a comprehensive look at the primary literature refutes it. There is a grain of truth to it, however. It was/is believed that Antarctica would accumulate snow in the interior due to increased precipitation. However, the possibility that Antarctica would still be a net source of SLR was certainly not ruled out. And moreover, the assertion that increased precipitation would result in an offset of “all” ice-sheet-related melt is simply, flatly unfounded.
It would take millenia [sic] to melt it all…
Fuller picks up the goalposts of “dramatic loss of Greenland and/or Antarctic ice” and runs with them. Now we’re discussing melting every last bit of ice! My, oh my.
In the real world, nonlinear decay of ice sheets contributing to rapid, multimeter sea level rise on sub-millennial timescales is not only possible, it has already happened. Meltwater Pulse 1A (MWP-1A) is an event that took place ~14.6 thousand years ago involving sea level rise of ~20m in less than 500 years, with several meters of SLR coming from the Northern Hemisphere’s Laurentide Ice Sheet and the remainder from the Antarctic. The paleoclimatic evidence is unambiguous: dynamic ice sheet collapse is not a purely theoretical concern- it can and has happened. We have provisional observational evidence of the mechanisms that make such rapid collapses possible. As such they must be considered in any policy or economic analysis of mitigation. This isn’t environmentalist fearmongering, it’s how CBAs are done.
But even excluding hyper-abrupt events like MWP-1A, concern over 1 meter or more sea level rise is well-justified by the scientific evidence. Using a semiempirical approach to derive the relationship between SLR and temperature change, Vermeer and Rahmstorf find more realistic current (and in turn higher future) values than the IPCC numbers:
But, in a scenario that many will find sadly familiar, those with a political agenda have grabbed on to some straws, such as the GRACE studies we looked at yesterday, and are busy hyping possible mechanical changes to the ice sheets (which do happen) and are simultaneously trying to blame those mechanical changes on global warming. They hijacked the science and spun it. (It’s not the scientists–not in this case.)
Here Fuller refers to recent GRACE satellite studies showing that not only are the GrIS and WAIS showing net losses of ice, but that these losses are in fact accelerating- exhibiting exactly the kind of behavior that gives you SLR higher than the 18-59cm Fuller “believes in”. Predictably, Fuller doesn’t accept that evidence, despite its agreement with other sources of data, such as ICESat.
(While there has been no shortage of denialist keystrokes spent hyping a recent paper revising the net losses downward due to a revision in isostatic rebound numbers, the existence of the net negative mass balances and acceleration themselves remain unchallenged.)
In short, Fuller ignores the paleoclimatic and observational evidence that tells us that sea level rise under unchecked warming can receive significant contributions from the nonlinear decay of the Greenland and West Antarctic Ice Sheets- and exceed 1m or more- on sub-millennial timescales without either collapsing entirely.
When the evidence is alarming, to the uninformed those describing that evidence sound like alarmists.