Sea level rise:a modest proposal

[nickbarnes]

Global sea-level is forecast to rise a metre or so over the next century. In the spirit of dumb-ass geo-engineering proposals to combat global warming, we should consider the most obvious geo-engineering approach to sea-level: pump sea-water into endorheic basins (that is, areas which don't drain into the global ocean), such as the basins of the

Comments

[nickbarnes]

Salinity: endorheic basins are already really salty places. We're going to destroy their ecosystems because we're flooding them, not especially because we're flooding them with salt water.
Pumping costs: Eyre and Caspian fill for free as they are downhill: all they need is some really big canals. There may be other large downhill ones; I haven't checked. Aral can probably be filled for free by using a variation on hydrostorage power engineering. Chad and Tarim not so much.
Flow rate: 4e14 cubic metres in a century is 1e5 cubic metres per second, roughly, which is 0.1 Sverdrup or about half an Amazon. Yes, it's a heck of a lot, but geo-engineering projects are always a bit jaw-dropping in that way.
Overflowing: We have different data. Wikipedia's list of basins says that Tarim is 1.152 million square kilometres. The total area of the top 5 endorheic basins is about 10 million square kilometres, i.e. 1/40 the area of the world ocean. So we need to put 40 metres depth in them, on average. Some of them have higher watersheds than others, so can be filled deeper. Left as an exercise for the reader.
To get a list of the basins, go to the Wikipedia list and click on the "Drains to" column head to group the endorheic basins together. Also notice that the Central Asian Internal Drainage Basin doesn't have an area listed.

[yea_mon]

I got an area of 400,000 km2 for Tarim on Wiki, which is 400 billion square meters - so we're dealing with a factor of 3 difference.

On the subject of salinity - I was not aware of that fact. I wonder if pipe-leakage will result in salinity changes to the water tables in the areas around them?

As an aside - have you reached your 5-insurmountable items yet?

[nickbarnes]

Wiki can't decide on the area of the Tarim basin: it has two pages which disagree. Possibly the 1.2 Mkm^2 figure is the overall drainage basin, whereas the 400k figure is the central plain within the basin. I suppose we could follow the citation links, but nah.
The oceans are salty because salts in rock dissolve in rain water, and the rivers carry it to the sea where it is concentrated by evaporation (and eventually re-deposited into salt rocks when a part of the ocean is separated into an endorheic basin - by uplift or tectonic shift - which then dries out). Endorheic basins are salty for the same reason. This is why the Dead Sea is so salty, and the Great Salt Lake in Utah is another well-known example. The Caspian is salt water, although less salty than the world ocean. The Aral is exceedingly salty, but was approximately regular salt water before it was wrecked.
5 insurmountable items: I'm not sure, because it's unclear to me how absurd a geo-engineering idea has to be before people stop proposing it. Compare this plan with (say) the often-aired idea of spraying sea water onto ice sheets to shift the mass balance.

[jwburton]

We're going to destroy their ecosystems because we're flooding them, not especially because we're flooding them with salt water.

You'd think, but in the Dead Sea case, real hydraulic engineers have looked hard at the problem, and they are worried about salt-water intrusion into the Negev aquifers, triggered by adding dilute salt water to the most concentrated salt water in the world at the lowest spot in the world. Unfortunately, there isn't quite enough power in the 400m drop to desalinate it all.

[nickbarnes]

Since Israel does so much desalination anyway, can't it make lots of hypersaline water and use that?
I can't find any numbers about the endorheic basins in the Sahara, which is another obvious candidate for this mad scheme.

[jwburton]

My understanding is that the aquifer problem is osmotic, and that adding still more salt to the basin is always problematic, while adding water is harmless (and removing water is an air quality hazard but not an aquifer hazard). It's possible that I'm wrong; I know some of the right people at the Weizmann Institute to ask if you're seriously interested.

[nickbarnes]

if you're seriously interested
Heavens, no!

[jwburton]

If we buried the nuclear waste first, and then flooded Nevada, there might be substantial economic synergies despite the unfavorable kinetic energy balance. For one thing, you no longer need to worry about containment, but only about good mixing (which is surely an easier problem). The solution to pollution is dilution, as the engineers of a more audacious age used to say.