A group of MIT researchers is exploring a radical idea to tackle global warming: using a cloud of “space bubbles” to reflect sunlight off our planet, reports Freethink.
The vast amount of greenhouse gases that humans have emitted into the air since the Industrial Revolution forms a kind of blanket around the Earth, trapping heat in the atmosphere and causing global temperatures to rise.
Most scientists agree that humanity needs to drastically reduce emissions to minimize the most serious effects of climate change, such as rising sea levels, severe droughts, and increased extreme weather events.
Unfortunately, it doesn’t look like the world is ready to give up fossil fuels just yet, so some researchers are considering a radical plan B: geoengineering the sun.
The idea behind solar geoengineering is that we can cool the Earth by reflecting some of the sun’s radiation off it. Although there are several different ways this can be done, the most widely studied technique involves injecting reflective aerosol particles into the upper atmosphere.
However, once these aerosols are released, there will be no easy way to catch them if the plan fails or has unintended negative consequences.
Instead of injecting particles into Earth’s atmosphere to cool the planet, an interdisciplinary team of MIT researchers is proposing solar geoengineering in space.
In particular, the group is investigating what might happen if we placed a bubble shield at the L1 Lagrange point, a point in space where the gravitational pull of the Earth and the Sun creates a kind of equilibrium that would keep the shield in orbit indefinitely.
The proposed shield would be about the size of Brazil, and the bubbles for it could be manufactured and deployed in space, possibly from silicon. The group has already experimented with creating these “space bubbles” in the lab.
“In our preliminary experiments, we succeeded at inflating a thin-film bubble at a pressure of 0.0028 atm, and maintaining it at around -50°C (to approximate space conditions of zero pressure and near-zero temperature),” the researchers say.
Because the bubbles would be nearly 1.6 million km from Earth, the MIT team says this approach to solar geoengineering would not be as risky as methods that directly involve Earth’s atmosphere.
“Most geoengineering proposals are earth-bound, which poses tremendous risks to our living ecosystem,” Carlo Ratti, who heads up MIT’s Senseable City Lab. “Space-based solutions would be safer.”
This isn’t the first time someone has suggested putting a solar shield in space to cool the planet, but building it out of bubbles would provide a relatively easy way to abort a mission if it goes wrong: the bubbles could just burst.
“This would make the solar geoengineering solution fully reversible and significantly reduce space debris,” MIT researchers write.
For now, the MIT team’s radical idea for solar geoengineering is still only a proposal. More research and experiments are needed to determine exactly how we might create, deploy, and destroy space bubbles.