Geoengineering is the category of technology that includes ideas that aim to intentionally alter our climate. With the aim of limiting the. “What we could do… if we keep doing nothing”joked David Keith, at Harvard University (USA), on the occasion of a TedEx conference in 2007.
All kinds of technologies fall into this category. The technologies of(CO2), for example. In its latest report, the Intergovernmental Panel on Climate Change ( ) announces that we are no longer in a position to do without it. If we still hope to limit global warming to 1.5°C.
But geoengineering is also about other technologies, which are a little more controversial. Because they aim to modify our climate quickly and on a large scale, without always being assured of the acceptability of the collateral effects. Like the technologies that somehow aim “to intervene at the source”to play on the solar radiation that the Earth receives.
This is what a team of(MIT, USA). The idea: send the bubbles into space to deflect some of the rays of the that hit our planet. Because researchers estimate that deflecting just 1.8% of solar radiation could be enough to reverse the .
In case the weather gets out of control
Concretely, the researchers plan to deploy a real raft of. All on the side of the Lagrange point L1. That point in space between the Earth and the Sun at which the gravitational influence of the two bodies cancel each other out. The optimal position could actually be a little bit closer to our Sun and a raft stabilization mechanism — possibly based on the geometry of the raft — would then be necessary.
The envelopes of these space bubbles could be made of a thin layer ofor a reinforced with . That remains to be determined. The researchers have already launched a series of tests. To find out if it is possible to inflate silicon bubbles under conditions similar to those prevailing in space. Under a around 0.0028 only and at a temperature of about -50°C. But further studies are needed to be sure of selecting the right material and to determine the ideal thickness of the envelope for these space bubbles.
The technology needed to inflate them in space is also still to be developed. Just like the one who manages to launch the bubbles into space. Why not, a kind of magnetic accelerator?
According to the researchers, the big advantage of their project is that this raft of space bubbles does not directly interfere with terrestrial ecosystems. And should therefore pose less risk to our planet. But this remains to be verified. This raft could also very simply be destroyed — which, from another point of view, raises the question of itsbecause researchers estimate that it could be useful for 50 to 200 years — when it has become superfluous — or if it turns out to have unexpected side effects. All without generating too important. And even gradually to avoid too violent a shock to our Planet and its inhabitants.
But before such a raft can float in space, a lot of work will still be needed. Work that MIT researchers believe it is necessary to begin. To be ready in case our climate spins out of control. Because they also remind us that such a project cannot, under any circumstances, replace the efforts to limit ourof and adaptation to global warming.