A new development from MIT proposes to launch into space giant bubbles that will serve as a shield against solar radiation. A logical solution to the climate crisis or crossing a red line?
Amnon Director, Zveta - Science and Environment News Agency
Try to imagine yourself looking up at the sky. You raise your head, recognize the Big Dipper, point to the Milky Way, and there, in addition to the stars, you also see a group of large bubbles floating above you. Sound like science fiction?
new development from MIT University, developed by a team of space scientists and architects, proposes to launch into space special giant bubbles that will serve as a kind of shield from solar radiation. The bubbles are expected to block and divert the direct solar radiation, which is one of the causes of the rise in global temperatures. "It is an idea that has elegance and incredible sides," says Prof. Yoav Yair, dean of the School of Sustainability at Reichman University, whose comprehensive article on climate engineering will soon be published in the scientific journal "Ecology and Environment". "Physically it might work. However, from a scientific, technological and operational point of view, there are many open questions around it."
Bubble bursts
The original idea for the project Raised already in the early XNUMXs by the American astronomer Roger Engel. His venture was based on the deployment of rafts consisting of small inflatable bubbles, whose purpose is to protect the Earth from solar radiation.
In the current project, the researchers continued in a similar direction to that of Engel, and developed "Space Bubbles", which are made of thin films that reflect sunlight, based on materials such as silicon or graphene. It is estimated that the thousands of bubbles will be connected to each other in space - they will cover 8.5 million square kilometers, An area similar to that of the entire country of Brazil. These bubbles will be relatively easy to operate, it will be possible to remove them simply. The reflective films will serve as a kind of mirror that will deflect the direct radiation that hits the Earth into space. They are designed to be placed close to the Lagrange point L1 (which is between the Earth and the Sun), where bodies can remain in the same relative position in space with almost no energy investment.
According to the researchers' estimates, the bubbles will be able to reduce about 1.8 percent of the sun's radiation, a figure that may not sound high, but whose effect may be very significant, to the point of stopping the increase in global temperatures, according to them.
The project is currently in a theoretical and experimental phase, which includes the examination of the bubbles and their shadowing ability in the laboratory under the conditions of outer space, the examination of the economic efficiency, the impact on the climate and the ecosystem and the implications for public policy. The team of researchers hopes to obtain additional support for a feasibility study that will include additional experiments in the laboratory. In the next phase of the project, analyzes and simulations will be conducted, along with initial experiments in laboratory production. Later, the research will also examine options for launching the materials from Earth, including the feasibility of using magnetic accelerators (rail guns) that rely on the forces of opposing magnetic fields to propel objects at high speeds.
The researchers believe that the project may be one of the most effective solutions for deflecting solar radiation from the Earth: it is an optical solution (which concerns light and vision), and not an idea that might interfere with complex chemical reactions in the atmosphere; The bubbles are expected to reduce the intensity of radiation throughout the entire surface of the earth uniformly, unlike other solutions; Theoretically, the inflation of the bubbles, as well as their removal, will be under the control of the scientists, and the fact that the system is located in space is expected to reduce the interference to its operation.
engineer the climate
The "Space Bubbles" project is an example ofengineering climate: An active and large-scale intervention in the Earth's climate, in order to deal with the global climate crisis. The type of solutions offered by climate engineering is the product, among other things, of a disturbing opinion among scientists: many of them hold the position that The strictest compliance The targets for reducing greenhouse gas emissions will certainly not be enough to prevent the rise in global temperatures, if we do not act now.
Climate engineering researchers come up with bold ideas like Using bacteria and algae to fertilize the ocean with iron, compressing carbon dioxide into the seabed and blocking the sun by scattering dust in the upper atmosphere. Some of these ideas may work, and some may even be applicable on a large scale, but our understanding of their long-term impact is still lacking. "Our ability to manage climate engineering solutions accurately and prevent disasters is limited. We are not there yet," Yair testifies.
Also in the report of The panel Understood-governmental של How״ם To change climate (IPCC) stated that climate engineering is a secondary option and necessary only if it will not be possible to limit the increase in temperature on Earth to a manageable level. That is, only if there is no other alternative. Furthermore, last January Released Letter position On it Signed above 300 Scientists spatial the world. The letter calls for banning the use of methods that change the intensity of solar radiation on the grounds that today we do not know enough about the risks involved in solar engineering.
when there is no choice
As mentioned, climate engineering type actions are controversial; Scientists debate their effectiveness and dangers, as well as the moral questions they raise. The "Space Bubbles" project also includes reference to various problems: from the optics and mechanics of thin films in space, to the effect of shadowing on the Earth, to the implementation of public policy. That is to say, it is evident that the researchers dwell on the dangers inherent in the project in question as well.
"Scientists fear that a project of this type is too powerful and that it is impossible to control it," explains Yair. "Unlike satellites that can be controlled from afar, space bubbles are a type of 'launch and forget': they stay in space for years, so at the moment it is too dangerous a solution. If we suddenly change the amount of radiation that reaches the equatorial regions or the poles, we may cause unwanted reactions." An example of such a response is a massive change in the Earth's climate, the magnitude of which is hard to predict today. In addition to its level of risk, the method is relatively expensive compared to parallel solutions (such as dispersing dust in the atmosphere), and it will take 20-10 years for its implementation. However, according to Yair, "the work on studies that are perceived as science fiction, or not necessarily applicable - at the same time allows work on additional solutions, which may work and improve the condition of the planet."
Moreover, the researchers in the project emphasize that the "space bubbles" are intended to complement - and not replace - the current efforts to mitigate the effects of the climate crisis. According to them, the day may come when such an intervention will be necessary. "Climate engineering may be our last and only option," testifies Carlo Rati, architect and head of the laboratory where the new research was carried out.
Yair also agrees with the approach. "Climate engineering is a weapon of last resort," he concludes. "It is better not to use it unless at the end of the century we come to the understanding that we have already passed the point of no return. Only then will we have to discuss the applicability of such solutions.'
