Concerned that efforts to stop the flow of excess greenhouse gases being released into our atmosphere will not be enough to save us from a worsening crisis, MIT engineers have returned to a decades-old vision to help mitigate the effects of climate change.
To buy time to wean ourselves off our dependence on fossil fuels, we could raise a parasol made of hi-tech bubbles over the planet to create shade.
The proposal to use a giant space umbrella, first proposed in the late 1980s, is not as far-fetched as it seems. And to be fair, it’s a far less risky plan than other major geoengineering projects aimed at bouncing light from the surface back into space.
Still, even if the basic concept of cooling the Earth with some orbiting shield is feasible, the materials required would not be readily available. They would need properties that would make them robust, lightweight, and optically suitable.
Initial designs focused on a 2,000 kilometer (1,200 mi) wide glass sandwich blown from materials mined from moon rock. Positioned in the exact balance between the gravity of the Sun and the Earth and the impact of the Sun’s rays and particles, it would reflect an amount of light calculated to moderate the steady increase in temperature.
Since then, various alternatives have been considered, from hydrogen-filled aluminum balloons to an artificial ring of particles that would turn Earth into a miniature Saturn.
All have pros, but the overwhelming cons mostly consign them to the “nice idea, shame on science” bin.
Still, desperate times call for desperate measures. Convinced that the primary benefits of a solar shield still exist, MIT scientists are calling for a feasibility study of deploying an array of foam bubbles the size of Brazil.
Once you get over the idea of dropping giant cans of shaving cream out into the interplanetary vacuum, it doesn’t sound so ridiculous.
Made from a homogeneous substance such as molten silicon, subtle thickness changes in the bubble wrap could reflect different wavelengths of sunlight, increasing its effectiveness. And unlike the complex origami required to fold and unfold large reflective fabrics before delivery, the bubble sheet can be blown into place, optimizing costs.
Best of all, should something unforeseen happen, it’s far more effective to pop bubbles than to raise dust clouds, summon hordes of tiny umbrellas, or shatter a city-sized glass.
In theory, such a shield would have a mass density of around 1.5 grams per square meter, putting it on par with speculative technology based on swarms of orbiting space umbrellas.