In this new study, scientists imagine ways to block out the Sun to let our planet cool. To do this, they suggest releasing moon dust. But this idea faces many problems, including ethical ones.
As the consequences of climate change become more visible each year, the calls to counter them are increasing. For example, finding solutions to reduce greenhouse gas emissions, reduce our meat consumption, or do away with fossil fuels. But some are looking for ideas… in space.
It is in any case what is found in the heart from a study published in the journal PLOS Climate. The authors describe how dust placed in orbit, between the Earth and the Sun, could protect us from the rays and therefore reduce the heat on our planet. ” The goal of our concept is to reduce the brightness we receive from the Sun “, details for Numerama the main author, Benjamin Bromley, astronomer at the University of Utah. ” We hope to be able to reduce the brightness by 1 or 2% with a cloud of dust in space. »
10 million tons of dust per year
An idea that seems straight out of a science fiction film, but described in a very technical way in this study. According to the authors’ calculations, the best would be to eject dust from the Moon: it is located on a good trajectory so that the grains are placed in orbit at the Lagrange point L1. The problem is that this orbit is not stable, and so the dust will eventually disperse after a few days, which means having to start again as soon as there is not enough left. In the end, it would take about 10 million tons of dust each year to achieve a lasting result. And the study clarifies that climate models predict a limitation of global warming in the short term if the brightness of the Sun drops from this level.
As surprising as it may seem, this study is far from being the only one to imagine a similar solution: it is the field of geo-engineering. A team backed by MIT, for its part, has been working for years on a concept of space bubbles which would form a screen between the Earth and the Sun. A very fine structure that would serve to limit solar radiation and provide us with a milder climate. Their argument for developing such a titanic project: “ If climate change is already too great, what could be our emergency solution? »
Benjamin Bromley has the same approach: “ It is an option for humans to have more time to solve their problems on Earth. In other words, this thesis considers that efforts to reduce pollution and resource depletion are too slow to take place, and that these technologies could provide a reprieve.
“There is an ethical problem”
But the project is far from unanimous among scientists. In general, geo-engineering meets with strong criticism: an open letter, at the beginning of 2022, warned of the ethical and political risks of this type of approach – this remedy could be worse than the email, according to these scientists.
” It’s techno-solutionism », Considers Olivier Berné, astrophysicist at the Institute for Research in Astrophysics and Planetology in Toulouse. ” Some like to count on it to solve the climate crisis, but it is above all a way of diverting the problem. »
Indeed, even on the assumption that these screens of dust or plastic would be sufficient to limit global warming – which has not been proven – they do not change the use of resources, on the contrary. ” The idea is to overexploit another territory, the Moon sums up Olivier Berné. ” This study is a patch which consists in continuing to consume in a reckless way, I do not think it is a good way to take the problem of the climate. »
Worse, imagining that it is possible to limit the luminosity of the Sun could encourage us to put aside the necessary efforts on Earth, since a less restrictive solution would seem to exist. But for Benjamin Bromley, the effect would be the opposite: Seeing how complicated our concept is to set up and requires so much effort, people will realize that it is easier to act on Earth, and this will encourage them to act sooner. »
“When you produce a scientific study, you have to ask yourself how the environmental issue is dealt with”
An announcement that leaves Olivier Berné skeptical: “ There is an ethical problem: when you produce a scientific study, you have to ask yourself how the environmental issue is dealt with, but also what impact this study could have on future social and ecological policies. »
For the researcher, who militates within the collective Labs 1point5 interested in the climate impact of scientific research, the environmental question should be taken into account for each research, as is the case for subjects related to bioethics or animal abuse.
Does this mean that we must prevent the publication of such studies, which are capable of doing more good than harm for science and the decisions that will be made later? For Olivier Berné, not necessarily: “ You never know what can come out of a scientific study when it is well conducted. And this is the case with this one, which is technically sound despite the ethical issues raised. »
A wall of dust between us and the Sun will never be the definitive solution to the climate crisis. This would ignore the effects of pollution and the scarcity of resources. But studying this avenue could lead to other more useful discoveries, the important thing being that researchers think upstream about what their work will bring to humanity.
Subscribe to Numerama on Google News so you don’t miss any info!
