There are many forms of thirst.
Nearly every genuine advance, whether based on old ideas or new, encounters greater difficulties than expected, but also becomes valuable in more contexts than expected.
The idea of exploiting the planet's largest resources of fresh water, namely our great ice sheets, has been bruited and mocked for perhaps a century, but though it repeatedly has been dismissed as stupidly unrealistic, the simple fact is that it is unavoidable. We will be doing that, like it or lump it, on a scale hardly imagined by either proponent or opponent. People will make and lose fortunes, people will die of it, and people will make livings from it as routinely as sailors sail and technicians build and tend wind turbines and high-tension lines.
The very ideas that visionaries espoused, towing icebergs for example, were non-viable.
It no longer is too early to think once more of harvesting ocean water and ice. Few people realise how unstable climate really is, with or without modern human culpability. Before our "industrial revolution" of the last three centuries or so, at least a dozen "civilisations", or at any rate established urban communities, were ruined or dispersed by droughts that lasted for decades or centuries. Collapses of that type have happened on every major land mass where cities of any sort existed. The biblical seven lean years were altogether believable as a very mild instance. The very Sahara as we know it, ancient and dreadful as it seems to us, is a relatively young desert, having been largely savanna just a few thousand years ago. It is so recent a development that apparently a few immemorial Atlas cedars still survive where rare underground water sources happen to have sustained them.
Many also don't even realise that much underground water is unusably salty, often saltier than seawater, and that when rainwater percolates through to salty groundwater, it becomes unusably salty in turn.
who steered their vessels through storms and mists, and increased our
knowledge of the lands of ice in the South.
These regions are remote from where many people live and work, and their ice is largely in unfriendly forms. Accordingly we have paid them little attention as sources of fresh water, but that must change. Just as we have been grubbing for oil in ever more incredibly difficult circumstances in recent decades, so we shall need to look at sourcing water from the more challenging, but more rewarding, less ecologically harmful, sources.
And gather the floods as in a cup, and pour them again at a city's drouth
The palms that wave, the streams that burst, his last mirage, Caravan !
And one — the bird-voiced Singing-man — shall fall behind thee. Caravan !
And God shall meet him in the night, and he shall sing as best he can.
James Elroy Flecker Song of the East Gate Warden
The traditional scheme for farming ice, was to cut slabs out of surface-frozen lakes, and some of that still gets done, but it is not an approach of much interest to our topic. It has nothing to do with transporting water to places that need it in quantities that could quench the thirst of cities and agriculture. Its very objective is not the same; those people sold ice as ice, not as water.
This is not my personal fancy, please note; people have experimented. The idea is a non-starter.
Ocean-going tugboats are built for two purposes: to tow huge inanimate objects across the ocean at a snail's pace or to slam
ahead at full speed into the teeth of a gale to come to the assistance of a vessel in distress. Of the two, it is hard to say which is the most
exciting. Personally, I found the long slow trips towing a dry-dock, a dredger or even a whole factory in the shape of a tin-dredger a more exacting experience than the salvage business. For, during the long trips, the officer of the watch develops a tendency to gaze astern instead of ahead, which he will find a difficult habit to lose. When, later, he is on watch on any other ship's bridge, pacing up and down at the comfortable walking speed that is the secret of relaxation, he will often experience a sinking feeling in the pit of his stomach on seeing the empty wake.
Jan de Hartog A Sailor's Life
The water from a billion-tonne iceberg would represent a significant addition to the water supply of even the largest city, but in every way would represent a challenge, both at the source and at the point of delivery...
We certainly would be fools not to take advantage of them, but that is not nearly sufficient on its own. Even the coldest currents would not be cold enough to prevent ice from melting, especially when it is being towed through salt water, and as it approaches regions where the water is wanted, the air temperature would rise dramatically, causing faster melting above water level.
The natural lifespan of a large tabular berg in sub-polar water, if it has a mean diameter of kilometres, is a few years, which is too short for towing even if towing were practical, and what is more, if we put everything we had into towing it, its lifespan probably would drop to less than a year. We would be putting all that effort into re-dissolving nearly all that water back into the sea instead of delivering it to a thirsty land.
Ensuring that the jacket would survive the trip long enough would be a serious challenge in itself; wave erosion and impact are shockingly powerful forces. Amylose film rather than non-biodegradable plastic plastic jacketing might do the trick, but I am not sure that any realistic plastic jacketing would last well enough on the business leg of the trip. At present amylose certainly would be too costly, but one never knows...
or half empty — and instead acknowledge that there's not
quite enough water to go around.
When you come down to it, the idea of towing icebergs is naïve. Towing them certainly does save all sorts of complications and ships, with no problems other than the loss of practically all your payload and the need for special facilities at the delivery end.
Jacques Yves Cousteau
Especially in the early days of gaining experience with polar water transport, we could experiment with second-hand tankers or tugs, but as experience accumulated, we might consider designing dedicated vessels for any of at least three options, all of them on a very large scale.
to do something about it, not when it's around your neck.
Ice has all sorts of disadvantages compared to water — harder to load, less dense, further to fetch, needing heat to make it usable, dangerous in large masses, melts inconveniently, can't be piped — the list goes on.
Such capture of carbon dioxide is regarded as very, very important, fresh water or no fresh water.
Preferably we would look for sheets a metre or two thick, or fairly undistorted floes. Sheets of drift ice could in fact be so precious that prospecting for them by satellite should be rewarding. Such ice is fairly salt-free and could be collected by fleets of harvester vessels.
The design of the harvesters could be based on modifications of ice-breaker principles; unlike the traditional icebreaker, that breaks through floating ice by riding up on it and breaking it, a harvester could invert the process by sliding beneath the crust and raising the ice in strips a few tens of metres wide and stacking them on board till the load reached capacity. It then could return the booty to the dispatching facility for processing while the harvester returned to its floe nibbling.
When the going gets tough the tough gets going.
After retrieving the valuable equipment for the next sheet of course.
Because of contact with the seawater, much of such molten ice would be brack, but as noted elsewhere in this article, even reasonably brack water is valuable. Depending on the most profitable options, it either could be delivered to market directly, or pumped into ponds on the shelf surface to freeze into plates of usable purified ice in winter.
by excrement, kills a child every fifteen seconds. That's more than AIDS,
malaria, or measles, combined. Human feces are an impressive weapon
of mass destruction.
Delivery of either ice or water has its attractions and each presents its own problems. Water is easy to pump aboard and ashore, and it is compact, either in itself or if we use it to fill the gaps between ice blocks in storage vessels' holds. But it also needs special precautions to handle at sea and it cannot be stacked like solid ice blocks. Also, its capacity for storing cold is small, compared to that of ice. In industry concentrated cold can be just as valuable as heat. That is why we spend money on freezers, heat pumps, air conditioning and the like.
Meanwhile the tugs could have returned polewards, taking previously emptied vessels with them. They might well have fetched a few more full loads on successive journeys by the time their previous load had been consumed.
You know, back in 1965, if someone said to the average person, 'You know
in thirty years you are going to buy water in plastic bottles and pay more for
that water than for gasoline?' Everybody would look at you like you're
completely out of your mind.
and tolerates shoddiness in philosophy because it is an exalted activity
will have neither good plumbing nor good philosophy: neither its pipes
nor its theories will hold water.
John W. Gardner
whether it is the waves or a waterfall.
This obviously sounds unattractive for clients near the equator, and there is no question of anything of the kind in the short term, but the need for water world-wide shows no prospect of decreasing. Meanwhile the population is increasing. There certainly will be an increasing need for global water reticulation. The necessary infrastructure will be far too huge to pop into existence suddenly. One of the early forms will very likely be large, long-distance ducts for shipping ice and slurry from the sub-polar regions to consumer regions.
the storm did not abate, we agreed to trust to God, Our Lord, and rather
risk the perils of the sea than wait there for certain death from thirst.
Alvar N. C. de Vaca
However, the cheapest, fastest and most sustainable desalination is the purification of large volumes of slightly brack water. It certainly is better and cheaper than trying to desalinate seawater.