A team of MIT scientists believe that ‘space bubbles’ could help reverse climate change by reflecting the sun’s heat away from the Earth. Researchers say cutting out just 1.8% of the sun’s rays could reverse global warming. It will be however several years before space bubbles might be put to use.
The bubbles would be manufactured in space by robots. They would form a ‘raft’ about the size of Brazil. The bubbles wold be placed at a Lagrange point, which is a point in space where the sun and earth’s gravity balance each other out, which in turn would keep the raft fixed in position. This kind of large-scale physical solution to climate change is called geo-engineering.
One of the crucial questions at this point is: Would geo-engineering solutions present a “moral hazard” by undermining support for climate mitigation policies and encouraging people to see the shift away from fossil fuels as less important?
Geo-engineering might be our final and only option.Carlo Ratti, MIT researcher
Several such ideas have been proposed. From spraying aerosols into the upper atmosphere to churning tiny bubbles on the oceans’ surface. All with the aim of reflecting solar radiation back into space. The scientists at MIT say that Earth-based geo-engineering solutions could be too risky as they might have unintended consequences for the biosphere, and that space solutions could be safer.
According to the World Economic Forum (WEF), the bubbles would be made of a thin-film material and manufactured in space. A space bubble is a variation of a solar shield, which would work by blocking out some of the incoming solar radiation to theoretically reduce the effects of global warming.
A key difference, however, is that with a space-based sun shield, there should be no risk of interfering with the Earth’s biosphere. Projects deployed within the Earth’s stratosphere do run this risk. Researches have underlined that the Space Bubbles proposal was designed to supplement not replace current climate change mitigation efforts.
“Most geo-engineering proposals are earth-bound, which poses tremendous risks to our living ecosystem,” said Carlo Ratti, MIT researcher. “Space-based solutions would be safer. For instance, if we deflect 1.8 per cent of incident solar radiation before it hits our planet, we could fully reverse today’s global warming.”
One advantage is that the bubbles could be deflated and removed from their position. According to the WEF, the spheres would be made from a material such as silicon, transported to space in molten form, or graphene-reinforced ionic liquids. The MIT team has carried out a preliminary experiment by inflating a spherical shell in outer space conditions. They believe it could be one of the most efficient thin-film structures for deflecting solar radiation.
Scientist James Early first suggested deploying a deflective object at the Lagrangian Point, while astronomer Roger Angel proposed the bubble-raft. The Space Bubbles project is currently just an hypothesis. The team would like to obtain support for a feasibility study that would involve further lab experimentation and analyses.
Options for shipping the material from Earth to space need to be considered. Several points need to be studied in detail, such as the possibility to use a railgun (a magnetic accelerator gun), the positioning and stabilization of the space bubble raft, shading capacity, cost efficiency, maintenance and end-of-life transition, climate and ecosystem impact, and public policy implications.