In the face of threatening climate change, it’s tempting for humans to look for a magic bullet–one technological fix that will solve all of our problems.
In recent years, several such proposals involve artificially modifying the climate. Climate scientists refer to these sorts of ideas as geoengineering, as they involve tweaking natural systems on a grand scale, and remain generally skeptical of them because they avoid addressing the real problem–that mankind is consuming resources at an unsustainable rate.
There are some limited cases in which geoengineering techniques can have a positive contribution to the fight against climate change, though. (We’ll look at some of those examples in a subsequent article.) But more often than not, geoengineering schemes are expensive, impractical, or ineffective. Here are five that just won’t work.
1. Put a huge umbrella in space
The problem at the heart of climate change is that the Earth is trapping too much heat. So why don’t we stop some of that energy from reaching the planet in the first place? That’s the thinking behind the space sunshade concept, which would reduce the amount of sunshine the Earth receives.
There are several proposals along these lines, including a cloud of trillions of small spacecraft or a lens similar to the ones found in lighthouses that would disperse a small amount of the sun’s energy out into space. In almost all cases, the plans would be not only prohibitively expensive but near impossible to manufacture with current technology.
2. Whiten the clouds
Lighter-colored surfaces are more reflective than darker ones, so by brightening the Earth’s clouds we could bounce more sunlight back out into space. How would we do that? By spraying seawater directly into the atmosphere–perhaps from the decks of unmanned yachts constantly sailing the globe.
While seawater and wind are relatively accessible resources, and the strength of the effect could be adjusted on the fly, clouds are atmospherically tricky. Given that we don’t fully understand the impact of different cloud types on the climate today, it seems unwise to try and fiddle with them too much for fear of unexpected consequences.
3. Spew iron into the ocean
Plants absorb huge amounts of carbon dioxide from the air. Obviously, we couldn’t live without them. But can we make them do more? An American businessman named Russ George tried: In 2012, he dumped well over 222,000 pounds of iron sulphate into the Pacific Ocean to create an artificial plankton bloom.
The idea was to suck more CO2 out of the atmosphere until the plankton died; it could then be dragged to the bottom of the sea and buried. George maintains that his experiment was successful–but dumping huge amounts of industrial chemicals into the sea is highly illegal under several international treaties, and he was swiftly fired from his job.
4. Dam the Bering Sea
The loss of Arctic sea ice is one of the biggest climate “feedbacks”–the white ice reflects sunlight so when it melts, the planet warms faster, melting more sea ice, and so on. In 2008, a Dutch science writer named Rolf Schuttenhelm proposed safeguarding the sea ice by building an enormous dam across the Bering Strait to block the flow of warm water into the Arctic.
It’s not the first time the idea’s been suggested. In 1956, the Soviet Union proposed a binational plan to the United States to artificially melt the Arctic by building a similar dam and then pumping warm water over it. The Americans rejected the idea outright, and the response to Schuttenhelm’s plan has been similarly chilly.
5. Fake a volcano
Whenever a major volcano erupts anywhere in the world, trillions of tiny reflective particles are pumped into the stratosphere. These particles reflect incoming sunlight, causing a temporary dip in global temperatures for a year or two until they eventually drop back to Earth.
Some researchers believe that artificially injecting these particles into the atmosphere–in essence, creating a fake volcano–could cool surface temperatures enough to allow us to continue burning fossil fuels without worry. However, early tests of the system in Britain were canceled following concerns about the lack of regulation around geoengineering projects.
How We Get To Next was a magazine that explored the future of science, technology, and culture from 2014 to 2019. This article is part of our Nature & Climate section, which looks at how human activity is changing the planet–for better or worse. Click the logo to read more.