Bjorn Lomborg makes the (by now traditional) claim that the new IPCC report has significantly reduced the estimates of projected sea level rises.
Six years ago, it anticipated ocean levels would be 48.5 centimeters higher than they are currently. In this year's report, the estimated rise is 38.5 centimeters on average.
But the 38.5 number Lomborg presents does not include increases from accelerating ice flows. About these, the report says:
For example, if this contribution were to grow linearly with global average temperature change, the upper ranges of sea level rise for SRES scenarios shown in Table SPM-2 would increase by 0.1 m to 0.2 m. Larger values cannot be excluded, but understanding of these effects is too limited to assess their likelihood or provide a best estimate or an upper bound for sea level rise.
IPCC lead author Kevin Trenberth (speaking on Science Friday) spoke on the sea level projections:
"The numbers in this report are actually very similar to the previous report, however they are reported in a somewhat different way"
Lomborg continues:
This is especially interesting since it fundamentally rejects one of the most harrowing scenes from Al Gore's movie An Inconvenient Truth. In graphic detail, Mr Gore demonstrated how a 20-foot [6 metres] rise in the sea level would inundate much of Florida, Shanghai, and the Netherlands. The IPCC report makes it clear that exaggerations of this magnitude have no basis in science - though clearly they frightened people and perhaps will win Mr Gore an Oscar.
Actually the report says:
The corresponding future temperatures in Greenland are comparable to those inferred for the last interglacial period 125,000 years ago, when paleoclimatic information suggests reductions of polar land ice extent and 4 to 6 m of sea level rise.
Now you could fault Gore for not saying how long this would take, but it doesn't look like there is a good estimate for this.
Lomborg:
The report also revealed the improbability of another Gore scenario: that global warming could make the Gulf Stream shut down, turning Europe into a new Siberia. The IPCC simply and tersely tells us that this scenario - also vividly depicted in the Hollywood movie The Day After Tomorrow - is considered "very unlikely".
Which means that they think that there is a 5-10% chance of it happening. It's not that improbable that Gore would have been justified in ignoring it.
And then we've got Lomborg defender and Republican Party favorite, Roger Pielke Jr. once again carrying water for the Bush Administration.
Within minutes after experts testified to Congress that NASA and NOAA are getting large cuts to their climate change budgets, RPJ quickly slops up a post of rebuttal.
http://tinyurl.com/37mu55
You'd almost think that Roger was on the White House staff.
Lomborg and CEI:
http://www.cei.org/2003dinner/index.htm
So over and over we seem to be seeing this single misinterpretation of the IPCC report which apparently is incredibly widespread among the people who dislike the IPCC's basic message.
Is there any way the IPCC itself could be convinced to issue some kind of clarification? It wouldn't even have to pass judgement on anything, it could just note the two numbers at hand are not directly comparable.
"Now you could fault Gore for not saying how long this would take"
Er, yes.
As one commenter to an earlier post noted, the 20-foot sea level rise is "catnip for wingnuts." It is worth noting that even this statement-- apparently the one considered most vulnerable by Al Gore's critics -- is scientifically solid.
From Greg Hoke's unofficial transcript, we have the relevant passage:
That's a concise and accurate description of the ice sheets and their support. Here's the money quote on sea level rise from destabilization of either mass:
Was Gore correct in what he said? Yes.
Yet, Lomborg is comfortable in saying "exaggerations of this magnitude have no basis in science - though clearly they frightened people and perhaps will win Mr Gore an Oscar."
It's clumsily snarky and wrong -- but it's aimed at Al Gore, so who cares? If you believe that he said he invented the Internet, you'll believe anything.
They did, right in the SPM, in the paragraph cited by Lambert.
The SPM is being subjected to quote-mining. Lomborg's smart enough to know exactly what he's doing, it's intentional. Any further clarification will be ignored ...
Yeah, but it *would* have been helpful if Al Gore been a bit clearer about possible time scales. Go on, admit it, you know I'm right.
Oh, yeah, he might've said "it might happen in the future" instead of saying ... um what did he say, exactly? "it might happen in the future?"
What difference does the timescale really make? You're saying you're willing to fuckover your great-great-grandchildren and you're happy with it because it won't impact your weekly golf game?
Is that the kind of point you're trying to make?
"The corresponding future temperatures in Greenland are comparable to those inferred for the last interglacial period 125,000 years ago, when paleoclimatic information suggests reductions of polar land ice extent and 4 to 6 m of sea level rise."
Judging by the Vostok Ice Core record (you'll have to plot it up), the temperature in the Eemian interglacial was sustained for more than 1.5C above pre-inducstrial for about 3000 years and sustained for more than 2C above pre-industrial for about 2000 years. We'll most likely get it above 2C for at least a few hundred years so I guess it's most likely that Greenland will go. The impact that's hard to predict is the one on West Antartica which was much more stable than Greenland in the past. The lowness of its bedrock makes it far more vulnerable than East Antarctica but I guess it might have some "protection" from being close to East Antartica.
it would have been helpful if Al Gore been a bit clearer about possible time scales
You're right. The catnippers surely wouldn't have latched on to it had he been more nuanced.
Are you sure about that? We are talking about the same person that was found not guilty of scientific dishonesty, because it could not be shown that he understod the issues well enough to be dishonest about them. In other word, if he had known what he talked about, it would have been dishonest, but since he probably didn't, he was just plain incompetent.
What's golf got to do with it? I play twice a week, walking, only CO2 I contribute is what I exhale. I should get carbon credits.
Topically, I once asked a particularly slow player if he'd allowed for the effect of the next ice age on the line of his putt.
I should get carbon credits.
Yeah, right.
A link to Roger Pielke Jr's take on the SPM sea level issue:
"I conclude that the IPCC has indeed lowered its top end estimates of sea level rise over the 21st century relative to 1990, in contrast to the conclusions at RealClimate which suggest that this has in fact not occurred. For details, please read on."
http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/00…
Hans, Greenland is not part of the WAIS.
Well, timing is important. Remember that CO2 will equilibrate with the deep ocean on timescales of ~500 years (couple of hundred years each way because there are multiple processes with multiple rates involved). Real Climate has an article on this which is worth reading, so if the sea level rise is slower than the mean rate for dilution of atmospheric CO2 into the deep ocean this is not as great a problem. On the otherhand, we may be near or past the point of no return for rapid breakup of the ice caps. Fact is we do not know.
Now as to the claim of large cuts in the 1990s to climate budgets, Eli points out in his typical mild mannered way that just looking at the budgets for climate work, something called Republican Control of Congress happened just at the point where the money vanished. RP attempts to rebut. We are looking for the budget requests. Those numbers many not be aggregated there....Hi ho, hi ho, it's off to search we go....
Hey, what happened to my incredibly witty and insightful response to dhogaza and Sven?
Never mind.
jre,
that link is very useful - thanks for that.
I'm guessing/hoping that somewhere there's a compilation of such handy links to source data, refutations of common arguments etc.
Do you happen to know of such a thing?
I was wondering when the corporate media was going to 'wake up the gimp' (of Pulp Fiction fame) in the body of Bjorn Lomborg and get hime to distort the latest IPCC report by downplaying it. Lomborg is a useful tool for the denial lobby because of his allegedly 'green' credentials, so they unwrap him every time another important report or study further consigns their views to the lunatic fringe.
Let's be clear here - the effects of climate change go well beyond sea level rises, an area where Lomborg spends the best part of 90% of his article. What about the effects on ecological food webs? Ecosystems? On a critical range of ecological services humanity depends upon for its survival and upon which there are no technological sustitutes? Lomborg steers well away from this area because he doesn't understand even the most basic science underpinning the function of complex systems. He has never studied popultion ecology. By ignoring it, he makes it appear as if no problem exists.
And sea level rise is important anyway. I've had an unfortuante spat with a friend who lives in the east of England, where the land is sinking. I was saying we don't need to get too panicky about sea level rise, and he pointed out the particulars of his area. 2 to 3mm a year adds up soon enough, especially if the area is sinking. London's Thames barrier will be inadequate much sooner because of the sea level rise. This will necessitate the expenditure of hundreds of millions of pounds on defences along the line of the Thames in a shorter time frame than if there was no global warming.
A cost that the denialists ignore completely.
"London's Thames barrier will be inadequate much sooner because of the sea level rise. This will necessitate the expenditure of hundreds of millions of pounds on defences along the line of the Thames in a shorter time frame than if there was no global warming. "
Good job there are no plans to build 300 000 hoiuses along the "Thames Gateway" then.... Oh.
I'd suggest to wait for some real sea level measurements, instead of extrapolating short data ranges.
The moment in time when it is observed that sea level has risen another 30 cm seems an adequate enough time span to me. I'll let you know by the end of this century. Or in a worst case scenario: 50 years.
Yeah, Hans. Nooooo need to plan ahead, cuz *COUGH*NEW ORLEANS*COUGH* that nasty ol' sea level will neeeeeeeever *NEW ORLEANS**COUGH* influence us in our lifetimes *KATRINA*COUGH*.../especially/ cities RIGHT AT THE EDGE OF THE FRICKIN' OCEAN...and it's not like some places already have a PRECARIOUSLY HIGH WATER LEVEL AS IT IS, no sir...
Millimeter Wave -- Sorry I didn't notice your question before now. Within my limited knowledge, the best effort at a climate FAQ specifically answering contrarians' talking points is Coby Beck's. Does anyone know of a better (or different) one?
Coby's place is the standard reference.
Best,
D