“No one seems to care about the upcoming attack on the World Trade Center site. Why? Because it won’t involve villains with box cutters. Instead, it will involve melting ice sheets that swell the oceans and turn that particular block of lower Manhattan into an aquarium.
“The odds of this happening in the next few decades are better than the odds that a disgruntled Saudi will sneak onto an airplane and detonate a shoe bomb.”
On the current IPCC estimates, sea levels should rise about 20-30 cm over the next few decades. A little googling located a map showing the effect on Manhattan of storm surges from a hypothetical category three hurricane. The large blue areas are areas that would currently flood. The tiny red areas show the additional flooding if sea level were 37.5 cm higher than it now is. The almost invisible yellow bits show the further flooding at 47.2 cm.Not that long ago, critics of the current administration were making fun of a statement attributed to an (unnamed) senior advisor to Bush, who supposedly described a critic as part of "the reality-based community." Judging by this particular example, if the advisor did say that, he was mistaken.
16 comments:
David,
Iirc, the world trade center is only a few blocks in from the ocean at the bottom left hand corner of Manhattan. According to the map, it seems to me that it would flood then. Or at least very close. In any case the margin of error must be large on those lines, so if we believe our climatologist friends there's at least a serious chance that it would flood.
Or perhaps I misunderstood the gist of your post.
*sigh* the zeitgeist these days!
pgm: I think the gist is that, along with large parts of New York City, the World Trade Center area would be temporarily "innundated" by a category 3 hurricane with or without a significant rise in sea level. It seems that without the rise in sea level, I could stand on the west side of 6th Avenue in Greenwich Village to avoid flood waters. With the rise, I may have to cross the street.
Errrr.....thanks.
You'll notice that David didn't spell out how high a storm surge that map was based on. Here's an appropriate articel that provides some details.
http://www.livescience.com/forcesofnature/061025_nyc_hurricanes.html
Now, if you have a roughly 20 foot storm surge, perhaps one to three feet of higher elevation due to rising sea level won't make a huge difference in area inundated.
However, David seems not to understand that the key thing is the frequency of these extrema: there hasn't been a 13 foot storm surge in Manhattan since 1821 according to the article. That one flooded large parts of Manhattan. Raise the sea level a foot, and then only a 12 foot storm surge would suffice to equally flood manhattan, and that is going to be much more frequent because it will require a much smaller storm.
Now, if a 13 foot storm surge is sufficient to flood lower Manhattan, including the WTC site, the additional 10 or 12 feet described as possible in the article would indeed make much of Manhattan as deep as the big tanks at an aquarium. And if global warming is increasing the frequency and magnitude of storms, that increases the probability of large storm surges.
Keep in mind that this isn't a problem unique to NYC: it is a worldwide problem. Coastal areas are the most densely settled and intensively developed and exploited. Increasing the probability of their devastation because of rising sea levels is nothing to snicker at. But it's an easy target for denialists. Doubtless they'd like to besmirch the notion of a "reality based community".
Mike, I suggest you reread the article. The article refers to the 1938 storm Category 3 near miss which produced a storm surge of 35 feet. The map which David linked to is a map which shows a "worst-case scenario Category 3 storm" (i.e., something similar to 1938) and compares the inundated area at today's levels with IPCC expected rises is sea levels. The Category 4 of 1821 was a "bigger storm" but produced a smaller surge because it wasn't a near miss. Given the map is based on something like the 1938 storm, you've gone off on the wrong track.
I think you need to do some reality checking of what the IPCC actually said. They are claiming that the average sea rise has been at a level of 1.8 mm per year, and could rise to 3.1 mm per year. (page 5 of the Feb 2007 IPCC report)
I understand that the metric system is not available in the US so let me put it into inches for you.
2.5mm is a tenth of an inch. An inch being 2.54 cm or 25.4 mm and should take around 10 years for the sea to be raised to that level.
You mentioned 30-40 centimeters or 300-400mm. that is just over a foot. So using very rough conversion rates. You are looking at 150 years for the sea to raise to that level.
Now, do you feel justifiably scared of the future yet? ;)
The levees in southern LA were designed, built and warranted by the US Army Corps of Engineers, and they failed well within their design specs. This had nothing to do with rising sea levels, and everything to do with egregious engineering errors.
And furthermore, New Orleans' difference between city and sea level is because New Orleans sank, not because sea level rose...
And if global warming is increasing the frequency and magnitude of storms, that increases the probability of large storm surges. This is speculative at best. Note, for example, the recent resignation of Chris Landsea as the IPCC's hurricane point person over its misrepresentations on this point.
Not speculative: a hypothesis based on the seasonality of storms corellating with higher Sea Surface Temperatures. See the first comment in the posting after the one you cite: http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/000325follow_up_on_landsea.html
(written by a friend of mine, it turns out!)
Of course, some would want to view this walkout as discrediting the IPCC and its work. A ludicrous demand for perfection. According to Milton Friedman, Von Mises once walked out of a Mont Pelerin meeting, declaring: "You're all a bunch of socialists." Shall this discredit libertarianism once and for all?
The simple fact is that hurricane data is intrinsically noisy: so noisy that if changes occurred recently, they'd be very difficult to show statistically. Thus, predictions made by SST trends.
Mike Huben said...
"Not speculative: a hypothesis based on the seasonality of storms corellating with higher Sea Surface Temperatures.
...
The simple fact is that hurricane data is intrinsically noisy: so noisy that if changes occurred recently, they'd be very difficult to show statistically. Thus, predictions made by SST trends."
1. I would have said that a hypothesis whose supporters hope it will be confirmed by future research is at this point speculative, and that is what your friend described, along with the reasons for forming the hypothesis.
2. The open letter by Chris Landsea was arguing:
a. There was no reason to think that this year's hurricane problems were due to global warming. He was objecting to a press conference by the lead IPCC author that asserted the opposite.
b. There was some reason to think that global warming was likely to increase the strength of hurricanes, but the predicted effect was small.
3. The open letter is relevant to our discussion here in two ways. First, it suggests that there is no good reason to expect global warming to result in substantial increases in hurricane activity. Second, it suggests that public information coming from IPCC, especially from press conferences and the like, may not be reliable.
Note, by the way, that the link you posted supports Landsea's view of the controversy with Trenberth:
"Absent at least one peer reviewed study to support Trenberth's claims, it would seem that he is, at best, a bit forward on his skis."
So we don't know if Trenberth's conclusion is correct, but we know that the statements he is quoted as making, in the page you cited, are false.
And also from the same piece:
" In particular, it seems odd that the head of the IPCC would assert that Trenberth's statements accurately reflected the work of the third IPCC assessment (in 2001), since they clearly do not (and also by Trenberth's admission as well). Landsea wrote much of the IPCC conclusions on hurricanes for the 2001 report, so he ought to know.
But more troubling than a lack of knowledge of the substance of the science of the IPCC reports is the political stance on climate taken by the head of the IPCC. "
And
"In taking such a political position in the highly charged context of climate change, Dr. Pachauri has placed himself in a highly conflicted position. If he were to have accepted Landsea's complaint as valid, it could be seen as admitting that an IPCC scientist is "overselling" the science in support of a political agenda. This could harm the prospects for advancing the political agenda that Dr. Pachauri advocates, so there is a strong incentive for Pachauri to dismiss Landsea's concerns. "
I realize the piece isn't from your friend--but he starts his comment on it with:
"Your arguments are entirely sound."
His argument is not that what Trenberth said about the current state of knowledge was true, but only that his opinion is that Trenberth's opinion is plausible and may be validated by future research.
I think the central point here is that, so far as I can tell, all three people--Landsea, Pielke (author of the piece you pointed at) and Wetzel (your friend) agree that Trenberth misrepresented the current state of knowledge in the field and that the head of the IPCC backed him up for political, not scientific, reasons. That's a situation that you ought to find disturbing.
I'm glad to see you're putting in all the worry words, such as "speculative", "not reliable", "highly conflicted", "overselling", "troubling" and "disturbing". They're very important for conveying how serious this is to you, and how portentious this tempest in a teapot is. I'm sure you've got your professorial dignity turned up to 11 for this. Perhaps you should also utilize that style for discussing the contrarians funded by think tanks. Or does this have something to do with confirmation bias?
Here's the followup from the same blog that should put your political worries to rest.
http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/001085follow_up_ipcc_and_.html
Note that it mentions that there IS a trend to more hurricanes, though the cause can not yet be attributed with confidence.
Here's another followup from the same blog that discusses the Landsea/Trendberth issue after two years.
http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/001105final_chapter_hurri.html
This should show you that there's really nothing to see here.
The way I see it, you guys are reading until you find something to jump on, instead of following the issue through to the conclusion. Perilously close to the tactics of thinktanks, creationists, and others involved in public relations, ie. propaganda.
This hasn't been your normal, extremely restrained style, David. Where's the modesty with which you proclaimed that you used economic arguments rather than moral arguments because you knew more of the former?
Mike Huben writes, about the comment at:
http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/001085follow_up_ipcc_and_.html
"Note that it mentions that there IS a trend to more hurricanes, though the cause can not yet be attributed with confidence."
That is not the case. What it says is:
"There is observational evidence for an increase of intense tropical cyclone activity in the North Atlantic since about 1970, correlated with increases of tropical sea surface temperatures. There are also suggestions of increased intense tropical cyclone activity in some other regions where concerns over data quality are greater. Multi-decadal variability and the quality of the tropical cyclone records prior to routine satellite observations in about 1970 complicate the detection of long-term trends in tropical cyclone activity. There is no clear trend in the annual numbers of tropical cyclones."
Note that the last sentence directly contradicts the claim of yours I quoted above.
Or in other words, no clear trend in total numbers, evidence of an increase in number of intense cyclones in one area in the past few decades but not enough data to compare that to the earlier period. And it also talks about upward trends in some areas and downward trends in others, which is a relevant qualifier to the discussion of a particular upward trend.
And one of the authors, commenting on the IPCC work, writes that:
"We concluded that the question of whether there was a greenhouse-cyclone link was pretty much a toss of a coin at the present state of the science, with just a slight leaning towards the likelihood of such a link."
You then point at:
http://sciencepolicy.colorado.edu/prometheus/archives/climate_change/001105final_chapter_hurri.html
which quotes Trenberth, in a later publication, writing that:
"[T]here is no sound theoretical basis for drawing any conclusions about how anthropogenic change affects hurricane numbers or tracks, and thus how many hit land."
i.e. that Landsea was right and Trenberth wrong in the original dispute.
The conclusion of that piece is that Landsea's actions pushed the IPCC into giving an accurate report on the particular question of frequency of hurricanes--reporting that "There is no clear trend in the annual numbers of tropical cyclones." The final conclusion of the piece is:
"But Chris Landsea should feel good as well because there can be no doubt that his actions helped to ensure that the IPCC got things right in the end."
I appreciate your efforts in digging up information for the discussion, but I think the evidence you found supports both parts of my conclusion from the Landsea dispute:
1. There is as yet no good reason to think that global warming is causing increased hurricane activity.
2. The IPCC process has been politicized, so one should view what it produces with caution.
Whoops! I wrote "more" instead of "more violent."
As a few of us have been pointing out, the problem with global warming and rising sea levels is worse EXTREMA, not the tolerable increases in averages. The average flood in a river valley might be 1 cm per year, but the 100 year flood of a meter is the one that destroys your house and car.
If you read on just a little farther, we find:
"Based on a range of models, it is likely that future tropical cyclones (typhoons and hurricanes) will become more intense, with larger peak wind speeds and more heavy precipitation associated with ongoing increases of tropical SSTs. There is less confidence in projections of a global decrease in numbers of tropical cyclones. The apparent increase in the proportion of very intense storms since 1970 in some regions is much larger than simulated by current models for that period."
So, numerous models predict worse storms. And current models can't account for how bad recent storms have been. I find that more worrisome than a few remarks by an official that have not been supported afterwards by the organization.
So here is my conclusion:
1. There is good reason to think that global warming is causing increased hurricane activity. There has often been anthropogenic change to the environment (think dust bowl, think acid rain, think smog, think invasive species), and of course scientific proof will lag behind hypotheses.
2. The IPCC process is by far the least politicized process answering important social questions. The opponents to this process have a long history of paying for propaganda that supports their financial stakes. Conservative foundations, extractive industries, etc. have a well-documented history of funding professional front organizations such as CATO, Heritage, Sound Science, Hoover, and others to produce propaganda opposing legitimate research. So one should view the arguments of the opposition with enormous caution, knowing that they have a lengthy history of proven conspiracy to subvert publicly important scientific research.
So I'm not impressed by gnashing of teeth over the molehill of Trenberth when you ignore the mountain of industrial tailings from corporate opponents and their shills.
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