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Post by edireland on Mar 11, 2013 9:51:34 GMT 9.5
6m sea level rise is not going to be catastrophic if it is spread over a century.
A small proportion of global GDP would cover the cost Dutch style flood defences for everyone.
(You might even bea ble to completely close areas such as the Irish Sea or what not with barrages, removing the need to build flood defences along those coasts).
It is probably the climatic issues with the intensification of the water cycle that will causet he problem.
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Post by stevek9 on Mar 12, 2013 5:02:26 GMT 9.5
edireland: You may be right. Anyone done a study? If you look at the Island of Manhattan it appears to be rising right off the surface of the water. A wall around it and all of the other coastal cities of the world? I feel a lot less sanguine about that than you.
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Post by anonposter on Mar 12, 2013 10:41:02 GMT 9.5
The Dutch managed to do it to quite a bit more than just their cities with much less advanced technology than we've got.
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Post by edireland on Mar 12, 2013 13:08:39 GMT 9.5
edireland: You may be right. Anyone done a study? If you look at the Island of Manhattan it appears to be rising right off the surface of the water. A wall around it and all of the other coastal cities of the world? I feel a lot less sanguine about that than you. Presumably rather than attempting to dam off the shores of iconic places like Manhattan Island, you would: 1. Install a dam across the Arthur Kill in the vicinity of Perth Amboy. 2. Install another dam across the East River between City Island and King's Point in Long Island (and obviously over the small channel between City Island and the mainland) 3. Construct a third dam across the Verrazano Narrows at roughly the same position as the bridge. 4. Install pumping stations. At full flow the Hudson River can dump more than 6800 cubic metres of water into the bay every second, lifting that 6 metres consumes only 400MWe. Average flow is roughly a tenth this. It would be prudent to overbuild capacity and distribute it across all three barrages to give redundancy. 5. Finally, install locks in atleast one of the barrages to enable ships to still reach the bay, river and the container ports, presumably building them in the Arthur Kill and East River barrages would be most efficient. Ship lifts could be provided for smaller vessels. This would completely seal the New York Bay, and it would enclose such a large area behind the barrages (it has to be 150 square kilometres of water easily as the river is still Tidal as far north as Troy) that even if all pumping stations failed wiith the Hudson at its maximum seasonal flow it would only cause sea level rise of approximately 17cm per hour. Which would give some time to get the pumps operational again. This would also turn the bay into a brackish water environment although it is unlikely to become completely fresh as it would still recieve injections of seawater from the working of the locks in the barrages. If the ports eventually close in favour of ones outside the barrages then the locks can be partially retired. It would be very expensive but still cheaper than building 6m high sea defences across all the coastlines that fall behind these proposed barrages. |
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Post by singletonengineer on Mar 15, 2013 16:25:51 GMT 9.5
Edireland has unwittingly produced a proposed "solution" which actually demonstrates just how far from a solution we really are.
Goodness knows how many folk live less than 6 metres above the high water mark of the world's coastlines, nor how much food is currently produced there, or how many species rely on the mangroves, estuaries and swamps. The numbers would be enormous.
My rough guess is that about half of the world's food and half its population would be adversely affected by the engineering works needed to hold back 6 metres of ocean.
Then what? Do humans continue till all ice has melted and 6 metres becomes 10? Then 15? Then 20?
Get real. Engineered solutions must address the causes, not the effects if they are to be reliable, affordable and sustainable. As in the health industry, prevention is much better than cure.
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Post by anonposter on Mar 15, 2013 18:42:03 GMT 9.5
Problem is we don't seem to be doing very well with prevention, even though we know exactly what we need to do (i.e. build nuclear power plants) so we're going to have to rely on cure regardless.
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Post by edireland on Mar 15, 2013 23:31:56 GMT 9.5
Edireland has unwittingly produced a proposed "solution" which actually demonstrates just how far from a solution we really are. Goodness knows how many folk live less than 6 metres above the high water mark of the world's coastlines, nor how much food is currently produced there, or how many species rely on the mangroves, estuaries and swamps. The numbers would be enormous. This is why we have to protect them from being drowned under 6m of seawater, like the Dutch have done with the polders we must do with most of the world's coastline. My rough guess is that about half of the world's food and half its population would be adversely affected by the engineering works needed to hold back 6 metres of ocean. Given the choice between "adversely affecting" those population centres and food production facilities, and leaving them under water, I believe there is only one choice, and that involves dykes the likes of which the world has never seen. Then what? Do humans continue till all ice has melted and 6 metres becomes 10? Then 15? Then 20? We have no other choice, unless you seriously propose abandoning that ground to the sea? Get real. Engineered solutions must address the causes, not the effects if they are to be reliable, affordable and sustainable. As in the health industry, prevention is much better than cure. Engineering prevention at this point is almost impossible. The "Green" movement has succesfully daemonised the only technologies that could hope to do the job in time. We will just have to live with 6m of sea level rise and hope we can adapt and possibly reverse it before it gets to its full extent. |
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Post by anonposter on Mar 16, 2013 12:27:52 GMT 9.5
We have no other choice, unless you seriously propose abandoning that ground to the sea? I find it highly unlikely that we'll manage to save all land so we should probably accept that we'll lose a lot of land and concentrate our resources on saving land that has a high population and let low population coastal land get covered (this would entail moving significant amounts of agriculture). |
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Post by David B. Benson on May 29, 2022 12:51:10 GMT 9.5
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