engineers want to blot out the sun to fight global warming. again.
With the climate crisis improving somewhat over the long term, but still posing plenty of dangers as Earth continues self-terraforming, scientists are getting desperate to provide solutions to slow the rate of warming and somehow circumvent government inaction. While some wander about sun-reflecting aerosols, others look to space, planning elaborate orbiting sun shades the size of entire nations. And the latest proposal from MIT is very much in the second column and comes in the form of giant silicon bubbles.
Overall, their plan resembles previous orbital sun shade ideas. Create a large surface capable of deflecting 1.8% of the light we receive, park it in one of the five Lagrange points where the masses of the Sun and Earth create a stable gravitational well — specifically L1 for this scenario — and make sure it keeps blocking the sun. Basically, it’s the Mr. Burns plan, but used for good as our politicians dottle and blameshift because of something about the economy. (Which will be under an awful lot of strain to mitigate the $178 trillion price tag of runaway climate change.)
Of course there are a few major catches. First and foremost is that photons from sunlight exert a force on any surface they hit, and while that’s not much of a problem for a typical spaceship, any large surface facing the Sun effectively becomes a solar sail. An improperly designed shade will just be hurled back at us as it’s being assembled. Fine, we’ll break it up into a myriad of smaller mirrors, right? We could do that, but making sure they all remain in sync will be very difficult and require a whole lot of fuel, constant supervision and maintenance, and corrective maneuvers.
This is where MIT’s bubbles come in. Using an inflatable, spherical design minimizes the impact of the photons and allows for easy adjustments in orbit. Each bubble can inflate and deflate as needed, and any debris that would shatter a flat mirror is likely to bounce off with little impact to each bubble and the swarm itself. They could also be made cheaply and launched in clusters, and their effect would be easily reversible should we ever get our collective poop together and finally clean up our act, unlike geoengineering efforts.
However, there’s still the problem that we’d need to launch enough bubbles to cover Brazil after they fully inflate, an area of 8.5 million square kilometers. And we will likely need another two or three million square kilometers worth on standby to replace burst or broken ones, or add to the swarm for more deflection should it be necessary. This means that the costs of the project would still easily reach in the hundreds of billions and cause significant additional pollution if we add up all the rocket launches required for its implementation, leaving us worse off in the process.
The best case scenario would be putting aside roughly the budget of the U.S. military, building a massive space factory where these bubbles would be constructed in bulk, then launched to L1 from orbit. But if we’re going to commit this much money and effort to mitigating climate change and global warming in space, why not just do it on Earth where it will actually solve our pollution caused problems in ways that yield exponential benefits down the line? Why waste all the cash on simply postponing projects we will still need to undertake later and at greater expense?
Ultimately, that’s the real Achilles heel of such projects. All they’d do is delay the inevitable and waste immense sums of money put to far better use on Earth where they’re already very sorely needed. As politicians will use these sun shades to keep doing nothing so as not to upset their fossil fuel and pro-pollution donors, the costs for remediation and a global transition to greener infrastructure will rise exponentially, which means these bubbles are likely to become just one more excuse to kick the can down the road instead of actually fixing the problem.
