Wednesday 21 March 2018

Sea-level sorted at source

I was on about the effect of climate change induced sea-level rise. Since the 1950s there has been a huge demand for beach-front property. If you read Laurie Lee on his travels through Spain in 1936, you'll find that the sandy beaches and hidden coves of the Costa del Sol were seen as deserts only fit for habitation by dirt-poor fisher-folk and their families. My own experience of the Waterford coast is that the half-life of a steel wheel-barrow is about 18 months if left 2km from the sea and its incoming salty wind. The lack of shelter from The Sea View, which is now so desirable, means that storms are fiercer on the coast and damage (trees down, tiles off, electric fails) much more likely than inland. Almost the whole Mediterranean coast of Spain has, since I was born, been covered with a narrow strip of bars, cafés, apart-hotels, time-shares, discos, banks, casinos, and shops anxious to part tourists from their money. This development is mirrored over many other coasts where a huge amount of investment has been made on the assumption that the sea will be in view but out there and not washing through the foyer of my time-share apartment block. In my piece, cited above, I was reflecting on the astronomical cost of protecting all that property if sea-levels rise by a few meters. We could imagine housing refugees from Seychelles, Tuvalu, Maldives, Kiribati, because these low-lying tropical paradises have relatively small populations. And the people of Hemsby on the East coast of England whose houses will be over the cliff in the next few weeks followed shortly after by a pub on the West coast. Holbeck Hall Hotel in Scarborough [live!] went in 1993. Bangladesh is a different matter entirely in housing a lot of people a few metres above current sea-level and not enough space in the rest of the country to take in the dispossessed.

But it is unfair and short-sighted to have each stakeholder operating in their own best interests. The River Suir which flows through Waterford City is flanked for much its upstream length by callows = meadows which flood whenever there is too much rain for the river bed&banks to take away. Having 1m of water sitting on your meadow is bad for the farmer because that's a tonne weight per sq.m. which compacts the soil, suffocates the earthworms and changes the microbial flora of the soil to anaerobic. It takes years to recover. Accordingly farmers have pushed up berms along the river bank which protects their grassland from these adverse effects. 
Q. Where does the water go?
A. It backs up and floods the streets, home and businesses of Clonmel.
If we lived in Padraig Pearse's socialist paradise, the property rights of farmers would not trump those of town-dwellers who buy their beef and potatoes from said farmers. Clonmel floods pretty much every winter.

In this week's Nature, John Moore and three other glaciologists describe a few cunning plans to solve all the problems of future sea-level rise by stopping sea-level rise. To a hammer everything looks like a nail, and glaciologists know how glaciers move. If you really understand a system, then you can start to imagine interventions. The knowledge which two generations of government-funded academic scientists have discovered about the pattern and process of inflammation have allowed MegaPharm Inc. to develop profitable anti-inflammatories. Moore&3more propose to Geoengineer polar glaciers to slow sea-level rise: stalling the fastest flows of ice into the oceans would buy us a few centuries to deal with climate change and protect coasts.  Here is the executive summary:
  1. Protect the leading edge of the biggest glaciers from contact with warmer ocean water by dumping millions of tonnes of rock on top of existing sea-bed undulations to prevent or minimise melt and keep the ice-bergs uncalved. The Jakobshavn glacier in Greenland accounts for 4% of 20thC sea-level rise. It could be insulated by shifting 0.1 of to create a berm across the 'estuary'. That's 10% of the volume shifted to dig the Suez Canal and that was done by fellaheen with baskets and shovels . . . with a bit of help from steam-power.
  2. Pin the leading edge of glaciers with immovable [ya hope] concrete pillars built up from suitable rises in the bed rock and/or creating new or extending existing islands. Some of these sub-projects will require a LOT more material to be moved, and stabilised. Not forgetting, as I say above, that the weather is rougher out at sea and moving water has tremendous destructive power.
  3. Dry up the lubricating sub-glacial streams. Glaciers slip along nicely when they experience summer surface melting which cascades liquid water down the cracks and crevasses. Even without that, the action of grinding thousands of tonnes of ice against an immovable rocky base generates enough frictional heat to lube up the under-surface. Moore&3more concentrate on the feasibility to getting access to the flowing water through 1km of frozen over-burden but seem short on ideas of what to do once they get there. Me, I'd pump down wood-chips to increase the viscosity. Twigs and brambles have been very effective at preventing water-flow in the drains at home so that water blurfs out into the road-bed to sweep the whole thing downhill in a heap.
You want to be super-skeptical about geo-engineers as hammers seeing nails everywhere. Seeding the oceans with iron and manganese to encourage bacterial growth and CO2 sequestration is right dodgy if you look beyond the immediate. And Transaqua's cunning plan for transporting millions of tonnes of water across Africa to re-fill Lake Chad, like a reverse Aral Sea, sounds like hubris to me [Last week]. Hubris = ὕβρις - over-weening arrogance inviting retribution. There will for sure be unintended consequences but if the alternative is to sit on our thumbs waiting for the End Times, maybe we should let the glaciologists have a crack at it?

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