Humans have been modifying the Earth for thousands of years, but we've barely scratched the surface of what's possible. Here are eight dramatic ways we could change the face of our planet.
For the purposes of this list, we're limiting the discussion to megaprojects involving the Earth's geology, atmosphere, and biosphere. This means no technological megastructures such as space elevators and sky hooks. That's a subject for another time.
(1) Global Weather Control
Weather control is a prospect that remains well beyond our technological reach, but that could change in the relatively near future. According to nanotechnology expert J. Storrs Hall, the author of Nanofuture: What's Next for Nanotechnology, we could start to build a weather machine later this century.
His proposed system would consist of a massive but thin global cloud of small transparent balloons stationed in the stratosphere. It would basically work as a kind of programmable and reversible greenhouse gas. When the mirrors on the hydrogen balloons face away from Earth, they would reflect sunlight back into space. When orientated sideways, sunlight could come through while allowing longwave radiation to escape. Incredibly, all the system needs is about a tenth of one-per cent of solar radiation to influence global climate in any direction we desire. (Image: NanotechNow)
Not only could we influence global and local weather patterns, we'd also be able to address climate change. What's more, we could even make large portions of the Earth more human-friendly and habitable (including Antarctica).
(2) Terraforming the World's Largest Deserts
The idea of transforming the world's deserts into lush forests goes back ages, and has many roots in science fiction. No doubt, our planet hosts some rather massive expanses of barren land; approximately one-third of Earth's land surface is a desert. Some are located in the polar regions (like Antarctica's McMurdo "dry valley"), but a fair portion are outside these frigid areas, including the 3.5 million-square mile Sahara Desert, the one million-square mile Arabian Desert, and the 500,000-square mile Gobi Desert. There's also Australia's interior to consider, the 250,00-square mile Great Victoria expanse.
A weather control system would certainly help to terraform these regions, but but other options exist as well. Leonard Ornstein, a biologist at the Mount Sinai School of Medicine, and David Rind and Igor Aleinov, researchers at NASA's Goddard Institute for Space Studies, have describe a plan to pump desalinated seawater from the coast to the Sahara Desert and Australian Outback. Desalination plants would acquire the needed energy from massive solar farms. The water would be used to irrigate crops, such as Eucalyptus grandis. Over time, these trees would replenish the soil and facilitate more rainfall. Depending on the size of the forest, it could fix as much as 8 million tons of atmospheric CO2. So not only would it make vast regions of land fertile and habitable, it could potentially end global warming. This plan was originally devised for Africa and Australia, but there's no reason why it couldn't work elsewhere.
Dune Planetologist Liet-Kynes. Following in the footsteps of his father, he sought to transform the desert planet of Arrakis into a verdant paradise. Could we do to the same do Earth's deserts?
But as Stuart Fox points out in Popular Science, this plan could introduce some nasty side-effects:
For one, sand from the Sahara is carried into the air, across the Atlantic, and deposited in South America. The rich dust that falls from the sky, and the rain storms caused by that dust picking up moisture during it's transoceanic journey both fertilize the Amazon rain forest. No desert, no dust. No dust, no rain forest. During that journey, the dust also feeds a variety of sea life.
Plus, the rain could cause massive swarms of locusts. Currently, wet years in the Sahara trigger serious population spikes of the destructive insects. With a permanent forest and heavy rain every year, Exodus-level clouds of locusts could spread across the entire continent.
What's more, it could cost upwards of $US2 ($3) trillion per year.
(3) Creating Artificial Islands
It may eventually be possible and practical to create new land. For instance, we could excavate the continental shelf to build a series of artificial islands. Interestingly, by raising part of the seabed above sea level, we could actually lower sea level by a similar amount -- a useful strategy for addressing rising sea levels on account of climate change.
Dubai Plam Jumeriah: This artificial island was built from 94 million cubic meters of sand a 7 million tons of rock. Future projects could dwarf efforts like these. (Credit UAE)
Retired geochemist Roelof Schuiling of Utrecht University has proposed an idea whereby the injection of sulphuric acid into limestone would cause it to turn into gypsum, making it grow to twice its original size. Thus, any shallow seafloor comprised of limestone could be terraformed into new land. According to Schuiling, this could be done at Adam's bridge, a narrow and shallow strip of shoals stretching for 22 miles (35 km) between India and Sri Lanka.
(4) Creating a New Continent
But why stop at artificial islands when you can build an entire continent? Such was the dream of German architect and megaproject pioneer Herman Sörgel (1888-1952). Writing in his highly influential book, Engineers' Dreams, Sörgel devised a plan to create the new continent of Atlantropa by damming the Strait of Gibraltar and the Dardanelles. This would cut off the Mediterranean Sea from the ocean, dropping its water level some hundreds of meters through evaporation. The resulting difference in sea levels would be used to generate hydroelectric power, and offer a powerful solution to Europe's energy problems.
The scheme would create 3.5 million square kilometers of arable land along the shores and provide overland access to Africa. And by damming the Congo River, the plan would allow for the irrigation of the Sahara Desert and the creation of massive artificial lakes in the African interior. (Above image: Artist's impression of Atlantropa (Credit: Lttiz/CC BY 3.0); inset image take from Sörgel's Engineers' Dreams)
But as noted by Kees Gispen in Project Muse, Sörgel's utopian plan was not only grossly unrealistic, it was also an expression of the early 20th Century European expansionist impulse:
The theme that inspired Sörgel's vision was unbounded technological optimism wedded to deep cultural pessimism -- geopolitical, demographic, racial -- about Europe's future in the aftermath of World War I. Sörgel believed that the war had fatally undermined Europe's position in the world, threatening it from the east with teeming Asiatic hordes -- a "yellow peril" about to engulf Europe -- and from the west with the rapacious dynamism of American capitalism. As Sörgel and his small band of followers saw it, only the realisation of Atlantropa would give Europe the strength to become a "third force" and maintain its global standing against Asia and America.
Disturbingly, and as Gispen points out, "the similarities between Hitler's solution to Germany's problems and Sörgel's seem perhaps even more significant than their differences."
(5) Eliminating Vast Swaths of Land
Conversely, we could also remove large tracts of land.
Five million years ago, the North American, South American, and Caribbean Plates converged. The new Isthmus of Panama restricted water exchange between the Pacific and Atlantic, diverting waters that once flowed through the seaway. The result was a strengthened Gulf Stream. (Oceanus)
As noted by Michael Marshall in New Scientist, we could relink the Pacific and Atlantic Oceans:
Destroying the Isthmus of Panama, the slender strip of land that joins North and South America, would reunite the Pacific and Atlantic oceans. Underground nuclear explosions would do the trick. With the land gone, the ocean current that once flowed around the equator would restart and, allegedly, stabilise the climate.
Of course, the folks living in Panama might have something to say about this. Not only that, it would produce serious downstream effects, including a dramatic decrease in northern latitude ocean temperature and the subsequent decrease of snowfall in the north, and calamitous effects on migratory terrestrial life in Central America.
Marshall also says we could flood the planet's vast depressions, such as the Qattara depression in north-west Egypt and California's Death Valley. This could serve multiple purposes, including the creation of new bodies of water, the generation of hydroelectricity, and as a means to offset rising sea levels from global warming. But on that last point, and as Marshall points out: "[It] is not worth doing for this reason alone: even if we flooded all of the world's major depressions, it would barely make a difference."
(6) Assisted Species Migration
Megaprojects need not be limited to the Earth's atmosphere and geology -- there's also our planet's biosphere to consider. Given that humanity has instigated the Anthropocene Era, we're going to have to give the plants and animals of the world a helping hand every once in a while.
"With climate change, the range of landscapes that a species is adapted to moves northward, often much faster than species can move," explains Ramez Naam, author of The Infinite Resource: The Power of Ideas on a Finite Planet. He says that's especially true for slow-moving ecosystems like forests and coral reefs.
"One thing we're pretty likely to do is to help those species move into their new zones -- planting forests further north, transplanting corals that thrive in extremely warm waters into other seas that are warming up, and so on," he told io9.
For reasons unknown, bumblebees can't migrate northward to avoid warmer temperatures. (Credit: Bernie Kohl/PD)
Recently, scientists learned that bumblebees -- an important pollinator -- are incapable of migrating northwards on their own. Since 1975 they have lost 300 kilometers (186 miles) of southern range and serious danger of being wiped out. Assisted migration has been touted as a potential solution.
(7) Eliminating Predation
The idea of eliminating predators from the ecosystem is certainly one of the most radical megaprojects ever proposed. And indeed, ridding our biosphere of predation would be a monumental task requiring technologies and foresight abilities far beyond our current capacities.
(Credit: Hamish Paget-Brown/CC SA 3.0)
But such is the dream of David Pearce, a British philosopher and futurist who imagines a future in which animals are liberated from the never-ending cycle of Darwinian processes and its attendant pain and suffering. Here's what he told me last year when I asked him if it was any of our business to interfere with the animal kingdom in such a sweeping way:
Humans already massively "interfere" with Nature in countless ways ranging from uncontrolled habitat-destruction to captive breeding programs for big cats to "rewilding". Within the next few decades, every cubic metre of the planet will be computationally accessible to surveillance, micro-management and control. On current trends, large nonhuman terrestrial vertebrates will be extinct outside our wildlife parks by mid-century. So the question arises. What principle(s) should govern our stewardship of the rest of the living world? How many of the traditional horrors of "Nature, red in tooth and claw" should we promote and perpetuate? Alternatively, insofar we want to preserve traditional forms of Darwinian life, should we aim for an ethic of compassionate stewardship instead. Cognitively, nonhuman animals are akin to small children. They need caring for as such.
To achieve and manage a post-Darwinian ecosystem, our descendents will have to rely on a large suite of sophisticated technologies, including genomics (for conducting gene drives, as an example), massive arrays of sensors and surveillance (both on the ground and from space), and artificial intelligence to monitor, evaluate, and compute the optimal parameters required for keeping the new system in balance.
(8) Mass Carbon Capture
As Ramez Naam explained to me, it's looking increasingly likely that we're going to pump carbon into the atmosphere well past the 450 parts per million / 2 degrees Celsius limit that scientists think it's vital to stop at. Consequently, we need to start thinking about "negative emissions."
"It's going to be increasingly important for us to capture carbon dioxide from the air and pump it into underground formations where it can stay for millions of years," he says, adding that the volume would be absolutely incredible -- on the order of several cubic miles every year.
Concept for Carbon Engineering's carbon capture "slab." (Credit: CarbonEngineering.com)
Physicist Peter Eisenberger has come up with a possible scheme. His plan would call for the deployment of scrubbers that use chemicals called amines that can capture carbon dioxide from the open air, where it's found at concentrations of 400 parts per million. What's more, his system would also be capable of recycling the amines. Less speculatively, carbon can be captured by a liquid solution of sodium hydroxide, which is a well-established industrial technique.
Geoengineering schemes on such a massive scale may be a necessity. But once we start, it will be practically impossible to stop.