Concerned that efforts to curb the flow of excess greenhouse gases that bleed into our atmosphere will not be enough to save us from a worsening crisis, MIT engineers have returned to a vision of decades to help to alleviate the effects of climate change.
To gain time to get rid of our addiction to fossil fuels, we could simply lift a parasol made of high-tech bubbles over the planet to create some shade.
First proposed in the late 1980s, the suggestion to use a large space umbrella to block a small proportion of solar radiation is not as exaggerated as it seems. And to be fair, it’s also a much less risky plan than other large-scale geoengineering projects with the intention of reflecting light from the surface into space.
However, even if the fundamental concept of cooling the Earth with some type of shield in orbit is feasible, the necessary materials would not be exactly available, and require properties that would make them robust, lightweight, and optically suitable.
Initial suggestions focused on a 2,000-kilometer (1,200-mile) wide glass sandwich blown with materials extracted from the lunar rock. Placed in a precise 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 mitigate the constant rise in temperature.
Since then, a variety of alternatives have been proposed, from hydrogen-filled aluminum balloons to an artificial ring of particles that would turn the Earth into a miniature Saturn.
They all have their advantages, but the overwhelming drawbacks relegate most to the trash of “a good idea, shame on science.”
Still, desperate times call for desperate measures. Confident that the fundamental benefits of a solar shield still have merit, MIT scientists are calling for a feasibility study on the deployment of a pool of foam bubbles the size of Brazil.
Once you get over the thoughts of throwing giant cans of shaving cream into the interplanetary vacuum, it doesn’t sound so ridiculous.
Made from a homogeneous substance such as molten silicon, subtle variations in thickness in bubble film could reflect a variety of wavelengths of solar radiation, increasing its efficiency. And unlike the complex origami needed to fold and unfold large reflective fabrics for delivery, a sheet of bubbles could be blown into place, optimizing costs.
Best of all, if something unexpected happens, it’s much more effective to blow up a bunch of bubbles than to catch clouds of dust, remember a multitude of tiny umbrellas, or break a city-sized glass.
In theory, this shield would have a mass density of about 1.5 grams per square meter, placing it on the same level as speculative technology based on swarms of orbiting space umbrellas.
Like many similar suggestions, technology should be kept in place by the tug-of-war between Earth and Sun to avoid the need for heavy guidance systems.
Ideally, engineers expect the entire system to be able to reduce the amount of sunlight that would otherwise cook our planet by 1.8 percent, a figure reached by previous studies. .
If they can find a material that can tick all the right boxes and find a suitable way to put it in position and then start blowing, it depends on getting funding for additional research. Of course, none of this has yet been published in a peer-reviewed journal: researchers are simply exposing the idea in the hope that future work can be done to build on it. So for now, these are more intriguing speculations.
Preliminary experiments have shown that it is possible to inflate thin film bubbles at a pressure of about three thousandths of an atmosphere, maintained at a temperature of -50 degrees Celsius (-58 Fahrenheit). But much more work needs to be done before we can consider putting the plan into action.
“We believe that advancing feasibility studies of a solar shield to the next level could help us make more informed decisions in the coming years if geoengineering approaches become urgent,” says Carlo Ratti, professor of urban technology at MIT Senseable City Lab .
None of this would mean easing efforts to curb carbon emissions, of course. Previous MIT research also implies that we need to be extremely cautious when it comes to any type of sun shade, with changing global weather patterns a clear possibility.
But in light of the evidence that disastrous temperatures could be reached in just a decade or two, it is clear that all options must be left on the table to be considered.
Don’t let these flashy big projects distract us from the real solution: stop emissions as soon as humanly possible.