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dr2chase at 08:31 AM on 24 July 2012Trigger for past rapid sea level rise discovered
chriskoz @7 -- The Greenland ice cap is not saddle shaped, but the land underneath it is.
What happens when ice melts in the middle; does it run to the bottom and collect there? Does it get part way down and re-freeze? It's hard to imagine the ice above melting fast enough (takes a LOT of heat) to create a saddle in the ice, but there is a saddle underneath. -
Martin Vermeer at 03:37 AM on 24 July 2012Esper Millennial Cooling in Context
Lambda 3.0, With "Figure S6" I assume you mean Figure S9, right? I'm not a treeringologist, but know a little about stats. You have to look carefully what is being plotted. The year number at the horizontal axis is the end year of an interval, of which the start year is 138 BC. Over this interval, a linear regression is performed. The core point is that the length of the regression period is very short at the left (538 years) and very long at the right (2138 years), and the data regressed is very "wiggly". Of course the trend variations due to the wiggling will then be considerably greater at the left end of the graph than at the right end. As we see. We also see that wood density gives different results then ring width. Due to the way this plot was made, also that difference has an effect on the plotted trends that grows going to the left (I suspect the tree-ring score differences themselves aren't any greater for the earlier times). About Figure 10, you have to look again at what is being plotted: 15-year moving-window correlations. So the "dip" at 1912 (I think) shows the correlations over the period 1905-1920. If you look at the upper part of the plot, you see that in this window, there happens to be only little variation in instrumental ("real") temperatures (black); these are almost constant over the window period. So, there is no temperature signal to cause corresponding variations in the proxy record, and no hope to extract good correlation values. The values we see (lower graph, colored curves) are more or less in the noise. The instrumental records for different stations show much better correlations among themselves (grey curves), because, well, purpose-built weather stations are more fit for purpose and less "noisy" than proxies-of-opportunity ;-) -
Alexandre at 00:23 AM on 24 July 20122012 SkS Weekly Digest #29
By the way, Beth Gardiner's article linked on this post is so good it deserved a post of its own! -
Composer99 at 00:14 AM on 24 July 2012Yes, Virginia, There is Sea Level Rise
RonManley: From previous discussions on this site (and examining all the graphs posted in this thread) it is my understanding that the principal driver of fluctuations in sea level rise (but not the trend) is ENSO; with the many La Niña years recently causing an appreciable dip in sea level rise. This seems to correlate with ENSO being a driver of fluctuations in surface temperatures, again without really affecting the trend in that metric, either. That would seem to account for the fluctuations you have remarked upon. -
anchr at 23:56 PM on 23 July 20122012 SkS Weekly Digest #29
Re geoengineering: yes. Once the realities of global warming is obvious, even for those who don't even want to look for it, geoengineering is likely to be the next line of defense. Partly as an argument for continued inaction, like KBow point out, but also partly because there will be a lot of money in this, that that will attract the same companies that makes a lot of money from oil extraction today. Although inaction on GW has made a lot of damage, getting geoenineering wrong might totally overshadow any damage we've seen so far. Besides, in that context they might be as opportunistically optimistic about the climate models as they are critically dismissive of them today. Thus, I think it is very important for this site to counter 'bad geoengineering'. -
KBow at 23:28 PM on 23 July 20122012 SkS Weekly Digest #29
The potential for geo-engineering is likely the next big argument to further delay action in favor of fossil fuel burning. Understanding the hurdles and risks will be important in developing opinion in whether we should delay action because we have a "cure" or if we should take an ounce of prevention. I would like this information explained to see if it would be reasonable to add this as part of the long-term solution. -
Bernard J. at 23:03 PM on 23 July 2012Trigger for past rapid sea level rise discovered
John Mason's comment at #20 cuts to the chase. The real problem of sea level rise does not involve big numbers. A rise of more than a few metres will place indecribable pressure on future generations, already labouring under the stresses of a heated planet with a seriously degraded biosphere and dwindling energy, soil, water and other resources. These few metres of sea level rise are already set in train with the current rate of human-caused global warming and its concurrent SLR change, and given a little more time than the arbitrary time limit of 2100. It's these simple, little numbers that will have huge consequences. And most human action these days continues as if these future consequences are still only hypothetical. -
Daniel Bailey at 21:48 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Chris Machens, you disappoint me. The source you link to, despite hosted on a university website, is a slide presentation nearly devoid of source attribution. As such, it is little more than opinion. Which is cheap these days. You stake your reputation on essentially hearsay. -
Alexandre at 21:36 PM on 23 July 20122012 SkS Weekly Digest #29
About geoengineering: I resist to admit the need of that kind of half solution, but yes, SkS should discuss those possibilities as well. It would even help people know their limitations, and it would help putting the low-carbon alternatives in better perspective as well. -
chriskoz at 21:29 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Martin@18, Thanks for correcting my typo. Chris@21, You should know by now that the claim of "potential SLR of 180m" in that presentation is unsubstantiated rubbish. I have also noticed another problem: in their simulation of GIS melt on slide 17. They assumed CO2 reaches 550, 750 and 1000ppm (3 scenarios) and stays constant after that for almost 3000y until 5000AD. That's very pessimistic/unlikely because, according to Archer 2009, figure 1 therein, pulse 1000GtC in the atmosphere cannot stay constant for so long, because its tail is reduced to 350-450Gt in just 1ky timescale after ocean invasion and neutralization by CaCO3. So their scenarios assume humans to keep burning coal (or some other CO2 release, e.g. from permafrost) into 5000AD to keep up with ocean CO2 uptake. That assumption cannot be substantiated. CBDunkerson@22, Thanks for puting it together. Now the numbers make sense to me. -
CBDunkerson at 20:45 PM on 23 July 2012Trigger for past rapid sea level rise discovered
chriskoz wrote: "This article incorrectly puts a figure of SLR 9 m in 500a during MWP1A, whereas the quote from www.nature.com reads "14–18 metres over 350 years" which is substantially different figure." The article stated: "The melted ice flowed into the oceans leading to rapid sea level rises of 9 m in 500 years during the Meltwater pulse 1a event 14,600 years ago..." AND: "The meltwater pulse produced by the saddle-collapse can explain more than half of the sea level jump observed around 14,600 years ago." 9 * 2 = 18 No 'substantial difference'. -
prokaroytes at 20:05 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Here is a paper from Colorado University with the same 100 meter flood map http://atoc.colorado.edu/~dcn/ATOC1060/Members/Lectures/26_SeaLevelRise.pdf The author claims it is unlikely but if all ice melts it could be up to 180 meter? -
John Mason at 19:47 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Danial @#14 has it about right. We need not wave big numbers about here. 2m would be pretty serious; 10m would be catastrophic, regardless of whether it occurred within 100 or 500 years. It takes a lot - an awful lot - of time and expense to relocate a coastal city - and there are an awful lot of 'em! -
Martin Vermeer at 19:40 PM on 23 July 2012Trigger for past rapid sea level rise discovered
This is the thread to link to when Tony Watts again claims that the "alarmist" side doesn't call out their own... -
Martin Vermeer at 19:38 PM on 23 July 2012Trigger for past rapid sea level rise discovered
chriskoz #16:The PETM studies calculated the temp rise of deep ocean as 8K from O18 ratio. The corresponding thermal SLR was 5m, which is about 1.1% vol.
Surely you mean 0.11%? -
prokaroytes at 19:09 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Chriskoz, the USGS 2003 numbers assume a maximum SLR (without thermal expansion) of 80 meters. http://pubs.usgs.gov/fs/fs2-00/ And as i said above, i have no interest in discussing if there will be 80, 90 or 100 meters SLR equivalent. he impact from massive SLR will be felt globally differently, depending on the planets gravitational field and mass movements. Therefore will an ice free state have SLR of above 100 meters. -
chriskoz at 18:35 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Chris Machens @13,...i have yet to see any hard data about thermal expansion. Current SLR is attributed for the most part to 70-75% thermal expansion i see no reason why this should change considerable
You can calculate termal expansion from this data and the average ocean depth of 4000m. The PETM studies calculated the temp rise of deep ocean as 8K from O18 ratio. The corresponding thermal SLR was 5m, which is about 1.1% vol. Your number of 30m indicates thermal volume expansion of close to 1%, which is equiv to 45K temp rise in the link I provided above. Not strictly the boiling point yet so physically possible but pointless to even consider as whole life (except some bacteria) would be dead long beforehand. So before claiming "I see no reason why this [thermal expansion component of SLR] should change considerable", check you basic maths. -
barry1487 at 16:53 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Thanks, Daniel. Still, the article doesn't reflect the uncertainty in the abstract. The link seems to be busted - maybe a wrong backslash in there? Here 'tis if anyone else is having my problem. http://www.bristol.ac.uk/news/2012/8626.htmlModerator Response: [JH] The embedded link in the introduction to the OP has been fixed. Thank you for bringing this to our attention. -
Daniel Bailey at 16:10 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Chris, on what basis do you: 1. Maintain there will be less ocean upwelling? Do you think the upper surface layer exists in a vacuum, disjointed from the layers below? We know that the deeper layers are warming, thus we know both upwelling and downwelling still exists between the ocean layers. Please furnish a credible mechanism under which this might occur. 2. Assert that current SLR attribution to thermal expansion will not change? Indeed, current understanding is that it is indeed changing, with the component due to melt already increasing. With many meters of ice-melt/mass loss already in the pipeline (century+ timescale). 3. The 100-meter assertion was yours, thus it is yours to defend. If you screwed up your maths, then admit it. What we (you and I, not the rest of SkS) have in common: 1. The GIS and the WAIS are screwed. Indeed, in a future sense their melt has already happened (when one views time a certain way), based on today's CO2 levels and the forcings/feedbacks derived from it. 2. Yes, 20 meters SLR is catastrophic, and may/will happen (given time). The point you miss is that 2 meters SLR is catastrophic, and will likely happen to the world's seaport cities ere the centuries end. All SLR which happens after that, and which will continue for centuries, is moot. 3. Yes, we are changing things many times faster than any comp in the paleo record. And also faster than mankind as a species can wake up to and internalize. And thus, mitigation is likely already out as a viable option. Which leaves suffering and adaptation. The former on a global scale; the latter, on a much smaller scale (for those that still live). -
prokaroytes at 15:25 PM on 23 July 2012Trigger for past rapid sea level rise discovered
I think that you and others missing a lot of the future environmental setup. This begins with less ocean upwelling - hence less cooling of the upper surface layer. Rohling and Hansen say 70 meters SLR from melt water alone and i have yet to see any hard data about thermal expansion. Current SLR is attributed for the most part to 70-75% thermal expansion i see no reason why this should change considerable. And with modest "natural" climate changes as discussed in this article here, we have already a realm of SLR within a few centuries. It makes a lot of sense to assume that anthropogenic driven SLR will advance much faster, as we know it does, from our observations. Maybe it is not 100 meters but even 20 meters will be catastrophic. I really have no intention to argue about a few meters and that is why i wrote below that image that it is not accurate. The point is that things will be faster than in the past of earth history and any modelling is helpful in our learning and understanding of this threat. So if we know that within 350 years a SLR of 18 meters can happen, than we can assume that the magnitude with faster Co2 addition to the system, will have an effect on the timescale. We are today 10.000 faster than the natural process. And we have data from coral reef proxies which show rapid SLR within a few decades. -
Daniel Bailey at 15:10 PM on 23 July 2012Trigger for past rapid sea level rise discovered
And again, addition of water/ice sufficient to raise global sea levels by even 70 meters would have the effect of dampening much of the thermal expansion you anticipate as most of the mass added will be near the freezing point of water. That level of ice mass added to the world's oceans would occupy nearly 100% of the world's SLR over that period. And if you were to ask Eelco Rohling if your timetable of SLR had any merit he'd also be incredulous. And (how I hate this repetitiousness) I have indeed re-read your post. All previous criticisms still stand. Despite that fact that I am still the SkS author most likely to be in your circle, you are not convincing. -
prokaroytes at 15:02 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Again. The point is to show what the impact of an ice free state looks like. Also i suggest you re-read the post since it got updated. For a further discussion on the topic i invite you and others to comment on that post, since it is off topic here. -
Daniel Bailey at 14:53 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Again, Chris, even a 70-meter SLR implies the entirety of the GIS, WAIS and the EAIS will have to melt/make its way to the sea in some fashion by 2100-2200 for your graphic in your blog post to have any semblance of accuracy. Show me some comp in the paleo record whereby 70 meters SLR was achieved in a world already at an interglacial peak and then you will have my attention. As an FYI, I touched on SLR impacts around the world in this SkS post: http://www.skepticalscience.com/mapping_sea_level_rise.html -
prokaroytes at 14:35 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Also the liquid is not distributed equally. Which suggest that some part will be considerable above that figure and other less so. The point with the image of sea level rise is to show us the future. Because with current emissions, we will get there. -
prokaroytes at 14:32 PM on 23 July 2012Trigger for past rapid sea level rise discovered
To quote from my post: The paleoclimate record also shows that 560 ppm would be enough to melt all the ice in the Arctic, and later the Antarctic. Rohling said that once the Antarctic melts, sea levels would rise by 60 to 70 meters. “If governments keep going the way they are going,” Hansen added, “the planet will reach an ice-free state.” Now it would be interesting to know exactly what the maximum possible thermal expansion could be on top of the melted water. -
chriskoz at 14:24 PM on 23 July 2012Trigger for past rapid sea level rise discovered
This article incorrectly puts a figure of SLR 9 m in 500a during MWP1A, whereas the quote from www.nature.com reads "14–18 metres over 350 years" which is substantially different figure. This article does not explain Heinrich events (5 of them between 45ka - 15ka) each attributed to the melt pulse of 5m/100a. Other than that, the results are good news: Greenland dome does not have "saddle shape", so future warming can spare us the MWP1A and 8.2K-like events. -
angusmac at 14:10 PM on 23 July 2012Christy Exaggerates the Model-Data Discrepancy
Dikran Marsupial @32 I am not quibbling about the diagram. My version of the AR4 Figure TS.26 is much clearer than the SkS Figure 2 from RC. Incidentally, @24, have you had any success digging out your data for Figure 2?Moderator Response:[DB] Cease with your dissembling. Figure 2 (taken from this RC post) are for global model runs. The IPCC figure you cite a portion of is for NH only. You compare apples and porcupines.
Continuance of this posting behaviour of dissembling will result in an immediate cessation of posting rights.
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chriskoz at 14:08 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Chris Machens, The maximum SL in the top warmth of Eocene (~40Ma) was 70m above present. I find your claim that it could rise 30m further above that is less likely than runaway greenhouse effect, during which the water would boil at the surface while the bottom part would remain cold. So the total volume of ocean would not have a chance of thermal expansion to reach your figure before it starts to evaporate. -
Daniel Bailey at 14:07 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Barry, note that this SkS blog post is a reprint. -
barry1487 at 13:56 PM on 23 July 2012Trigger for past rapid sea level rise discovered
I think this article would be improved by including caveats. The scientific conclusions may be strong, but not definite. Uncomfortable with absolute language here. -
Bernard J. at 13:46 PM on 23 July 2012Greenhouse effect has been falsified
I'm certain he has an explanation. They always do.
Don't they just? And the operative word is "an". The explanation doesn't need to be the correct one, because the intent here is to sow fear, uncertainty, and doubt. Purely and simply. Richard Pearson's target audience is the unsure, non scientifically-educated swinging voters who form a large proportion of his and his colleagues' voting constituency. Sadly, most of them are not as cooly logical as Philippe, and frustratingly there never seems to be a simple way of getting across perceptive points such as his. Pearson doesn't need to be right; he just needs to be convincing. -
chriskoz at 13:42 PM on 23 July 20122012 SkS Weekly Digest #29
I'm annoyed by the vulgarity of the crude text-box to enter the comments. It's inconvenient to type those "a" "i" "blockquote" "img" tags, needless to say I never remember the syntax and i.e. often produce bad links. Preview button + hyperlink help is not enough. Is there any WYSIWYG editor that would do it for me? If not possible to link WYSIWYG editor to this Comment box, can anyone recommend a simple & easy external editor for that? -
Bernard J. at 13:37 PM on 23 July 2012Vision Prize Results
I also echo John Hartz @15 in that WUWT commenters are the radical fringe, not at all representative of the general public.
Dana and John. I certainly acknowledge that Watts' commenting fan-base is over-sampling from the extreme end of the anti-science pool. My concern is that they have a disproportionate influence in policy, and this was increased recently as a result of an off-the-cuff straw-poll a colleague conducted of non science-specialised students. Around a third believed that there was a serious scientific debate about the evidence for climate change, and of those a majority thought that the science had been done incorrectly or was compromised by personal interest on the part of scientists. Most of the students referred to "the internet" as a source for their doubts of the science. Whether this is more representative of such students generally still has us scratching our heads... Amongst my non-tertiary educated friends and relatives there is a strong propensity to believe that there is no smoke without fire in tabloid stirring of the idea of a debate about the science of climate change. It's classic fear, uncertainty, and doubt. I'm sure that they're not as extreme in their beliefs as the Watts crowd, but the issue is whether they let the fundamental notion of the 'unreliability' of the science influence their decisions when voting and 'consuming'. The overall glacial pace of government action around the world would seem to reflect this. In the Australian context I guess that one test of the general public's ability to balance the realities of climate science against the tabloid 'uncertainties' will occur at the next federal election. One counter to the FUD campaigns of the blog science-denial industry is the presence of initiatives such as the Vision Prize, and I certainly hope that they are able to separate the denial noise from the surveying of the signal of scientifically-qualified opinion. -
Daniel Bailey at 12:12 PM on 23 July 2012Trigger for past rapid sea level rise discovered
Chris Machens, I am considered one of the more "alarmist" among the SkS ranks, yet your claim on your blog of 100 meter SLR over the next 100-200 years is quite frankly incredulous. For one thing, not enough ice exists to cover that gap due to melt nor do 1-2 centuries give enough time for full thermal equilibria of the ocean depths to be reached to get the full thermal expansion effects. I'm happy to entertain many possibilities, no matter how wild, but in the end it comes down to physics and evidence. As the esteemed Martin Vermeer suggests on your blog, perhaps you should check your maths. As it stands, your comment is not very on-topic for the OP of this thread. -
Paul Magnus at 07:46 AM on 23 July 2012Trigger for past rapid sea level rise discovered
Anyone monitoring the height of the Greenland dome? -
prokaroytes at 06:25 AM on 23 July 2012Trigger for past rapid sea level rise discovered
Possible Sea Level Rise of 1-3 meters (or more) within the next 50 years Based on the current rate humans put Co2 into the atmosphere, which is 10,000 times faster than the natural processes. For that matter and potential singular positive feedbacks the rate of Sea Level Rise (SLR) can be assumed to rise with a similar rate. And for that matter there is no equivalent in the earth recorded history. The main SLR rise is likely not to come from melted water, rather then thermal expansion, which is attributed to be 70-75% of current observed SLR.Moderator Response: [DB] Fixed link. -
RonManley at 06:17 AM on 23 July 2012Yes, Virginia, There is Sea Level Rise
Rob Painting # 20. I don't say that the sea level rises all by itself. What the data do show that is the rate of sea level rise fluctuates in a quasi-cyclic way. You can download the Excel file I used here and check it yourself.Moderator Response: [DB] Fixed link. -
John Mason at 03:47 AM on 23 July 2012Joe Romm's Congressional Testimony
Good on Joe. It is high time we ditched the euphemisms and stopped pussyfooting about. We hung along for too long with the Banking industry - bowing to calls for deregulation etc - and look exactly where that has gotten us too. If that's not a wake-up call to us ordinary folk, what will it take? It's a brilliant world out there - under tremendous strain - but it is still managing, just about. Let's do everything in our power, however small that may be, to further the simple cause of wanting a brilliant world for our children and grandchildren and not a toxic, polluted mess where the last 'consumers' wander about looking for the last bargains. We can do this, folks - if we speak with one voice (and not a World Socialist Government voice, before anyone starts) - just the voice of the people, who love their gardens, the wildlife around them, getting their hands dirty with the soil of the land and who hate all the form-filling, box-ticking nonsense that is the facade of dealing with the biggest issue of our lives when pretence is the order of the day. I would rather see children knowing 100 plant-names and recognising 50 different butterflies by the age of ten - as I did many years ago - than knowing 400 brand-names by the age of five. That's just one aspect, but I hope people will see where I'm coming from! Rant over! -
Tristan at 03:13 AM on 23 July 2012Greenhouse effect has been falsified
I'm certain he has an explanation. They always do. -
Philippe Chantreau at 02:31 AM on 23 July 2012Greenhouse effect has been falsified
Tristan, if he is as bright as you suggest, then I'm sure he must have an explanation as to why there is so much more downwelling IR radiation reaching the surface than what the Sun emits. That is an easy, reliable, confirmed over and over, direct, real world observation, in total contradiction with the little experiment you link above. So allow me to be a little skeptical. Where does all that IR come from? -
Tristan at 21:15 PM on 22 July 2012Greenhouse effect has been falsified
Following from my earlier comment about our state MP who advocates against the science of climate change, here he is demonstrating that he's not just a politician but a brilliant scientist. -
Rob Painting at 19:41 PM on 22 July 2012Yes, Virginia, There is Sea Level Rise
Ron - The notion that the sea level simply rises all by its lonesome, as part of some mysterious natural quasi-cycle, is ridiculous. And yes, you are right climate models certainly don't allow for this physically impossible scenario. -
shoyemore at 18:40 PM on 22 July 2012The Mid-Wales floods of June 2012: a taste of things to come?
Found the Matthew Kahn video The Free Market as a Solution to Climate Change Kahn sees the insurance industry as a key "sender of a price signal" about housing. Governments should not help communities at risk because they will only attract more inhabitants to those areas. These ideas are refreshing. But one wonders, if inaction continues, how feasible is the "free market" if tens of thousands, if not millions, are simultaneously affected? -
Alan E at 18:29 PM on 22 July 20122012 SkS Weekly Digest #28
@ curiousd I have supported Carbon Community Foundation (http://carboncommunity.org.au) and know the two principles - Andrew Flint and Chris Trafford. CCF's mission is to replace kerosene lamps with solar lamps in villages that are off-grid. We're talking 300 million households so there's a lot to do. CO2 emissions are the tip of the iceberg - buying kero drains the household budget and burning it causes all manner of really bad health problems. And having cheap light at night aids home businesses and kids education. CCF are pretty young and have partnered with Barefoot Power (http://www.barefootpower.com/) and others who can bring the products and distribution channels. -
RonManley at 18:18 PM on 22 July 2012Yes, Virginia, There is Sea Level Rise
I should have posted a graph earlier to minimise the confusion. I calculated the rate of sea level rise based on the data of Church et al merged with the Jason-Topex data for recent years. The data start in 1870 so for every year from 1890 onward I calculated the rate of change of sea level in the preceding 20 years (very easy in Excel using LINEST).
This plot shows that:
1. There is an underlying increase in the rate of rise. It works out at about 1mm per year increase every 70 years.
2. The rate of increase in sea levels is quasi-cyclical. Thus, depending on the phase of the cycle it is possible both to have an underlying acceleration and short term (c 30 years) drop in the rate of rise.
Despite the implications I am not a climate change denier. I believe that the acceleration in the rate of increase is almost certainly due to global warming alone. I am also in favour of the decision relating to the citizens of Virginia being based on science. However since the rate of sea level rise is quasi-cyclical and since as far as I know (correct me if I am wrong) none of the model projections include this then the four year pause to get better science may be to their advantage.
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Neven at 16:32 PM on 22 July 2012The Mid-Wales floods of June 2012: a taste of things to come?
Like I said, it isn't working: Deadly mudslides sweep through Austria. More from the local media. Apparently we are witnessing a one-in-30-years storm here in Styria, except of course that the last one wasn't 30 years ago... -
Rob Painting at 13:54 PM on 22 July 2012Yes, Virginia, There is Sea Level Rise
Ron Manley - "Rob Painting #2. Your graph actually suggests the rate has been more or less constant from 2001 to 2009 at about 1 mm/year" Ron, I'm sure if one confines oneself to looking at any short interval you can find a short-term trend that affirms a preconceived notion. We call that cherry-picking. On the other hand understanding the physical mechanisms driving these trends is far more useful. For example, if a reasonably-sized El Nino develops this Southern Hemisphere summer I fully expect that sea level will rise abruptly - as the continental land masses, and particularly the tropical basins, dry out. Furthermore, as mentioned above, the loss of ice from Greenland & Antarctica is accelerating - this will manifest itself in greater sea level rise. The solar dimming of the Southern Hemisphere in the "noughties" has shielded the oceans from greater warming, but can much longer can that last? We've already seen that the slowdown in ocean heat content between 2004-2008 has been replaced by greater warming:
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Tristan at 13:37 PM on 22 July 2012Yes, Virginia, There is Sea Level Rise
Hmm. I wonder if my childmind misinterpreted 2200 as 2022. Possible. -
Rob Painting at 13:28 PM on 22 July 2012Yes, Virginia, There is Sea Level Rise
Tristan @ 14 - never heard that one before, probably because it is nonsense. Certainly the paleodata indicate rates of sea level rise of well over a metre occurred in previous warm intervals (interglacials), but there's no evidence to support rates greater than that. They may have occurred, but the evidence is lacking. -
Albatross at 12:50 PM on 22 July 2012Yes, Virginia, There is Sea Level Rise
Tom @13, Good points. Steve Chase is also wrong about what he claims is stated in the video about global sea level rise. The video starts of with reference being made to a press release from the Niels Bohr Institute, the heading for that press release is: "Studies agree on a 1 meter rise in [global] sea levels" Nowhere do they state 1.8 m as the best estimate for the increase in global sea level by 2100. Admiral Titley does note in the video that sea levels could rise between 0.9 m and 1.8 m by 2100 (~3-6 ft), and that range is entirely consistent with the GRL paper referenced below. So we have some "skeptics" here cherry picking values to misinform and to fit their narrative. That Niels Bohr press release in turn refers to a paper just published in GRL by Jevrejeva et al. (2012) who conclude that: "With six IPCC radiative forcing scenarios we estimate sea level rise of 0.6–1.6 m, with confidence limits of 0.59 m and 1.8 m." So as new information becomes available the best estimates of increases in sea level are being revised upwards. Now 2100 is rather arbitrary, because sea levels will continue to rise well beyond 2100 because of global warming.
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