I've come to the conclusion that nearly all geoengineering "solutions" face the problem that the same trillions of dollars they'd cost would have a far better ROI if simply invested directly into green tech deployment & R&D. And given the rapidly dropping costs of greentech, this problem gets worse the longer it goes on. It would be far better to focus energy on getting to zero-carbon than on crazy band-aids like this, however interesting.
I agree that for most things it can be true to do "other things"; however, the cost of this is a global investment the ROI is a good chance to at least restore sea-ice seasonally at a higher extent & volume in this critical area.
Please understand there is a Phase 2.
This was yesterdays' extent and the entire western part of the straits are fully open note the eastern shore still has ice.
http://www.mallard-design.com/mdc2010/media/sea-ice-5-20-2016.pngSeeing this years ago began the idea of creating a large estuary to deal with it, that became the freshwater supply to the shipping locks and can be freshened by pumping the water to the locks from the bottom.
That means it freezes earlier, if snow dumps on it for this limited area pumping water to remove its insulation value is worth the hassle to allow cold air to cool the water below the ice, the trouble at sea with snow is that it does insulate !!!
That's bad, you can't fight the warmer water with cold from above because of the snow, with more moisture and warmer air there's more snow.
The goal is preserving sea-ice in the eastern basin.
[Aside: For those who never designed a vertical-axis windmill, they are superior to propeller horizontal-axis for windspeed range and in the case of Arctic operation I'll post details for DIY & TIY, test-it-yourself, no way want to waste time on non-shop-people worries.]
For scale that's a much easier total area to focus upon and does not get ocean swells and pretty narrow, about 10-miles to allow some artificial peninsulas & islands to break its fetch.
Thus the question on ROI in relation to restoring sea-ice is, "Will it help create a sea-ice refuge?".
The answer is yes and what else will? You must answer that because restoring the sea-ice is mandatory to thermally balancing this planet, to me it flips the switch from ice-age earth to hothouse earth.
That's with a high confidence even without modeling to know that by preventing the wave action and warm current the ice habitat will extend season and thickness in the embayment.
Once this point is reached, the dam in and effects have metrics all aspects are known to then make a decision on Phase 2: Cape Serdtse-Kamen to Point Hope, the route map:
This is obviously a larger undertaking yet now dealing with a known construction method, still tides and river outflow it will be a "controlled porosity" structure in places not a waterproof one costs more to do that and could be islands with intentional passages for tides.
This fishery & sea-mammal habitat is huge, preserving traditional sea-ice seasonal length the goal along with the overall goal of increasing the "seed" area to gain larger scale effects out into the Chukchi Sea, the hope that effects the edge of the Beaufort by 2-decades later.
With this closure having a much larger extent of still-water, the geophysical goal to cool the water to the bottom in winter to -2C to prove the technique can work; if it does, then we can build atolls around degrading methane zones using this technique.
On the global scale this is dealing with the worst emissions in the Arctic and hardest to control.
With methane 100-times more potent for a decade or so this is another feedback the method attempts to control physically, these atolls having pumps using windmills to keep snow converted to ice by having a structure able to slab the ice ramming into it during the season.
Consider now the history of polders, by starting small and building upon a foundation to expand, they took over a lot of sea then maintained it as it sank from desiccation as land.
For the Arctic it's easier & harder and this is only for shallow seas my focus the East Siberia shelf as critical to control the Pine Island Glacier of many beds, thus consider this next phase is a mgmt system.
In the next step it's oriented toward sea-ice related habitat while allowing tides & river flow with intentional freshwater estuaries with the goal of freezing the bottom in areas to prove a methodology to deal with the clathrates later.
Phase 2, Cape Serdtse-Kamen to Point Hope