You might have heard of the Aral Sea and its “ships of the desert”. Where there once was seafloor, now there’s only dust; where there once was thriving fish and birds, now there’s only toxic clouds. All the casualty of diversion for agriculture, a plague upon the Earth’s freshwater seas, and though the worst disaster of its kind it’s far from unique. Which got me thinking: what would be the fate of such seas in a timeline, a science-fictional universe, like mine, the one I write my stories in?
The Aral Sea in 1989 (when it already had drawn down substantially) versus 2014. Yikes. At least Kazakhstan has taken measures to conserve their part of it (that northern piece that didn’t shrink…). Photographs courtesy of NASA, collaged by Producercunningham of Wikimedia Commons.
A “ship of the desert”. Yes, this is the kind of weird stuff that happens when a seabed becomes land. Wouldn’t it be nice if this was still a verdant natural sea? Photograph courtesy of Staecker of Wikimedia Commons.
The only Way out is Through?
Technology advances much faster and further, the economy grows far richer and more globalized over the course of the 20th century. I’ve penciled in that this leads to a burst of hydroelectric dam-building, which despoils whole landscapes with unsightly reservoirs; flood-control dams might also be even more common than they are today.
And it’s possible diversion of freshwater for agriculture might get even worse initially, though global population going through the demographic transition much faster relieves the pressure by now, especially in the less-developed countries that use less-efficient technology. Land used for agriculture has already shrunk slightly in the United States — in the northeast it’s common to come across low-lying stone walls in the middle of thick woods, because those woods used to be fields a century ago but have fallen into disuse — because of improvements in crop yields. With global population, and food demand, being like half of what it is today, and crop yields per acre being much greater than today, this reversion to nature will be much more dramatic; the lower Midwest will go from horizon-to-horizon corn fields to islands of corn in a sea of new-growth trees.
There might be even more trees in the originally forested regions, perhaps enough to approach complete restoration, if agroforestry catches on; crops can be grown under forests, and tree crops are a thing. Notably, tree crops can be used as feedstock for meat-yielding animals like pigs and cattle. And trees make excellent carbon sinks to boot.
Anyway, freshwater demands will remain acute in this scenario, shrinking lakes from the Salton Sea to Lake Chad worldwide. But starting in the mid 20th century, nuclear desalination will come to the rescue; using reactor heat, masses of seawater can be boiled and condensed into fresh water, to be sent wherever it’s needed via aqueducts. Nuclear energy in my world becomes extremely cheap by our standards, and thus nuclear-desalinated water becomes more and more economical as a source.
Coastal regions such as California will become completely reliant on this freshwater source, but over time aqueducts will be constructed connecting places deeper and deeper in the interior to this abundant water source. Helping matters immensely will be nuclear tunnel-boring machines, or subterrenes, that enable by the late 20th century extremely cheap tunnel-digging via reactor heat melting the rock. Transportation and other vital infrastructure in cities, and increasingly the countryside, is put underground, and fresh water is no exception.
Forget the Colorado River: the Pacific Ocean becomes the primary source of water for the Desert Southwest, delivered cheaply via tunnels extending from coastal nuclear complexes. The rest of the world follows much the same pathway as development permits. By the 21st century I expect nuclear desalination to be the primary source of freshwater globally.
The upshot of that is that there’s no more need for dams; environmentalists and conservationists get their way and the edifices are one by one torn down, the rivers allowed to run wild again, the landscapes despoiled by the reservoirs restored to their natural state as much as possible. Why not, when all the power and water the locals want is provided much more cheaply by nuclear technology? Indeed, the capacity exists by the early 21st century to manufacture more freshwater than people know what to do with!
Restoring all the Lakes!
With this infrastructure in place, the Aral Sea remains at peak health, and the California Central Valley’s Tulare Lake, which once was the largest freshwater lake in the U.S. west of the Mississippi River but had been depleted by 1899, might come back to full strength, along with its sister lakes Buena Vista Lake and Kern Lake.
Looks like a good place for some recreation, not to mention wildlife. Wouldn’t it be nice if we brought it back?
Protecting the freshwater Seas against Climate Change
The one remaining menace to the world’s great freshwater lakes in my timeline is climate change; in the case of the Salton Sea, even if its waterflow is not interrupted, it will likely evaporate eventually, as all its previous incarnations have. In our case that would be a big problem, since pesticides have accumulated on the seabed, and will, once dry, create toxic dust storms much like the Aral Sea’s have. Lake Chad too has suffered mightily as a result of climate change.
The solution, of course, is simple; build an aqueduct from the nuclear desalination plants to these seas, so new fresh water can be poured in to replenish what’s lost. In my setting I imagine the Salton Sea has been completely restored by this method and is once again home to a variety of hot-weather resorts.
The Salton Sea. Photograph by Rman 348 at English Wikipedia.
More intriguingly, Lake Chad could be protected from the ravages of climate change by the same method; take water from the Atlantic Ocean, desalinate it cheaply with a nuclear complex, and pipe it all the miles inland to the lake. Intriguing because Lake Chad is in a flat low-lying area, ergo its basin is shallow, ergo small changes in volume have big effects on its surface area. During the African humid period, before 5000 BC, it spanned 400,000 square miles’ worth of territory, larger than the Caspian Sea today! It might have stretched deep into northern Chad (within 100 miles of Faya-Largeau), and at the time it flowed out into the Atlantic Ocean via the Niger River system.
If you raised the water level this high you’d inundate millions of people, so most likely the maximum extent of today’s wetlands, where (as far as I can tell) the cities begin that draw on it for their livelihoods, is about as far as you’d want to take any “refill the inland sea” effort.
Or would you? Restoring Lake Chad to its prehistoric glory, interestingly, was envisioned to be part of the Atlantropa Project. Atlantropa’s best-known component is the idea of building a hydroelectric dam at the Strait of Gibraltar, which would then be used to lower the water level of the Mediterranean by up to 600 feet, opening up a large area of new land to be shared by the peoples of Europe.
Less well-known is that in addition to being a pan-European project it also envisioned unification of Europe with Africa into a single geopolitical bloc, known as Atlantropa. Its creator, Herman Sörgel, predicted the British Empire was not long for this world, and that pan-Asian and pan-American blocs were emerging to threaten European competitiveness in the long-run, so therefore a pan-European effort to colonize Africa was necessary. Sörgel foresaw that fossil fuels would be depleted, and that the Gibraltar dam would provide an inexhaustible source of energy; the Middle East, under the control of Atlantropa, would provide yet more energy. The massive public works would relieve unemployment, new lands opened up, both reclaimed from the Mediterranean and irrigated in the Sahara, would relieve overpopulation, and in a peaceful way, in stark contrast to the Nazi vision of “lebensraum”, i.e. living space for the people.
Atlantropa was rather ahead of its time, but much interest was lost after the peak of interest in the 1920s and 30s, continuing to simmer into the 1940s and 50s, with the advent of nuclear energy, making such a monstrous dam unnecessary for power. Nevertheless, it showed up as late as in 1979 in (of all places) Gene Roddenberry’s novelization of “Star Trek: The Motion Picture”. Yes, in Star Trek world, Atlantropa is supposed to be a thing. Would have been genius if they linked Atlantropa with that somewhat-sinister-sounding “European Hegemony” once mentioned as the beginning of world government in “Star Trek: The Next Generation”. Oh well.
Back in the real world, the general idea of giant dams to alter water levels in the region has continued to simmer, especially among Germans and Scandinavians. The Northern European Enclosure Dam proposed in 2020, though intended to counter global warming’s sea level rise, is basically Atlantropa North. There’s even a southern branch of Atlantropa: the Red Sea Dam proposed in 2007. And the idea of a channel to flood the Qattara Depression in northwestern Egypt with seawater has continued to simmer.
There are actually a variety of depressions and basins in the Sahara that could be, and indeed once were, filled with freshwater lakes. The Darfur, for example, while not much to look at these days, was once home to the West Nubian Paleolake (also known as Lake Ptolemy), which was a much cooler bit of geography than what’s there today. Indeed, it seems that our own Nile River is but the pale remnant of what was once a thriving network of rivers, lakes, and marshes that dotted the entirety of the Sahara.
Image from Dynamics of Green Sahara Periods and Their Role in Hominin Evolution, courtesy of Juan C. Larrasoaña, Andrew P. Roberts, Eelco J. Rohling. CC BY SA 4.0.
What if we could use the abundant water produced by nuclear desalination to make all these lakes fill their basins again? Now that’s an interesting thought.
Restoring Seas in the Desert…and making new Ones?
Has anyone actually done this in my setting? I’m not sure. I’m pretty sure that at least refilling Lake Chad to, say, the levels observed in 1900 would be done, but flooding enough land to make it bigger than the Caspian again, displacing millions of people? Seems like a bit of a stretch, but if French West Africa unifies into a strong state and the region becomes wealthy I could see them actually executing such a mad plan. Much more likely, though, would be filling with freshwater this or that ancient reservoir in the Sahara, most of which are uninhabited.
In addition to farming, which often does better with irrigation in deserts than in more naturally humid climes, but all manner of verdant habitats could be created around these reborn lakes for residents and tourists alike in the new Sahara. Eventually if you pushed it enough you could get some substantial “greening” of the Sahara desert, in a process not unlike what happened to Arrakis in the “Dune” chronicles. Like Arrakis, it’s technically feasible to even turn it, along with Earth’s other deserts, into a forest if you wanted to, but that process would take much longer than a century or so, which is how long it’s been in the 21st century in my setting since these projects started.
And in any case given the more general ethos of “rewild the Earth” in my setting, complete terraforming seems unlikely. Still, it’s an interesting idea. I know this all is a bit rambling, but contemplating these inland seas and their ecologies, the possibilities inherent in this space, proves many things, one of which is: geography isn’t nearly as fixed as you might think. Worldbuilders, use your imagination, and don’t be afraid to think big.