Climate change is a real problem. Human caused outputs of greenhouse gases like carbon dioxide and methane are the main driver of an unprecedented rise in global average temperatures at a speed never before seen in the Earth’s geologic record. The problem is so bad that any attempts to mitigate greenhouse gas emissions may be too little and too late. And so a team based at the Massachusetts Institute of Technology have proposed a radical new solution: bubbles…in space.
That’s right, bubbles in space. The thinking is based on two areas of concern. One is that try as we might to reduce or even eliminate greenhouse gas emissions moving into the future, the damage we’ve already done from over a century of advanced industrialization has already set the course of the Earth’s climate trajectory in a bad direction. It may be so bad that even if we were to completely stop all greenhouse gas emissions tomorrow, we would still have to live with the severe impacts of climate change for decades and even centuries to come, including continued rising sea levels, more extreme weather events, and disruptions to food producing regions.
Another way to tackle the problem is to sequester or remove carbon, or somehow limit the amount of sunlight reaching the surface of the Earth, for example by releasing aerosols into the atmosphere. The team at MIT argues that this is generally a bad idea because our climate system is so complex and dynamic that introducing artificial factors into the atmosphere itself cannot be reversed.
So that’s why they’re thinking space. The idea is to develop a raft of thin bubble-like membranes. Those membranes will reflect or absorb a fraction of the sunlight reaching the Earth by literally blocking it. The team argues that if the amount of sunlight reaching the Earth is reduced by mere 1.5%, we could completely eliminate the effects of all of our greenhouse gas output.
Personally I’m pretty skeptical about this idea. For one, the team has yet to articulate exactly what these bubbles will be made out of and how they will be sent to the target location, which is near the first LaGrange point of the Earth-Sun system. They will need to maintain stability of the raft by balancing the gravitational forces of the Earth, the Sun, and also likely the other planets. They will also have to contend with radiation pressure from the Sun itself, not to mention the constant rain of the solar wind and micrometeoroids.
To block even a percent of the Sun’s output would require a raft thousands of miles wide, which would make it the largest structure we have ever put into space. So there’s just a tiny bit of engineering challenge to make this thing work.
And while the MIT researchers claim that this space-based approach is fully reversible, that’s only in a certain sense. Yes, if we decide that the raft is a bad idea or not doing what we had hoped it would do, we could just let it float free or disassemble it. But the Earth’s climate is a complex system with many intricate feedback loops embedded in it that we do not fully understand. What would be the total effects of blocking the Sun’s light by one and a half percent over years, decades, and centuries? What effect would it have on the biosphere or the level of cloud cover or ocean evaporation or thousands of other considerations? Do we really believe that we have the technical and intellectual capacity to get this right?
Lastly, developing a solution that reduces the amount of sunlight hitting the Earth does nothing to address the underlying issue, which is that we are causing serious harm to the Earth’s climate and biosphere. If we have cover – pun intended – to do what we want, then why should we stop polluting or emitting greenhouse gases if we can just add more bubbles to the raft? We need to address these fundamental problems, not just paper them over.
The team admits that there’s a lot more work to be done, but I wouldn’t be surprised if after years of work the realities of the complexity of this proposed solution…pop their bubble.