Geoengineering

I read an interesting article today of a way to decrease the amount

sunlight so as to decrease warming of the oceans.

Here is the title:

MIT Scientists Propose Space Bubbles to Reverse the Worst of Climate Change

By Angely Mercado

6/16/22 2:48PM

 

The idea is to create a really huge “raft” of silicone bubbles which if positioned between the earth and the sun would decrease the solar radiation. I copy the article below:

A team of researchers at the Massachusetts Institute of Technology believe that we can mitigate the worst of climate change with… space bubbles. They’ve outlined a strategy in which a huge raft of bubbles, carefully positioned between Earth and the Sun, would deflect sunlight (and thus heat) to stop further global warming.

 

“Geoengineering might be our final and only option. Yet, most geoengineering proposals are earth-bound, which poses tremendous risks to our living ecosystem,” a web page dedicated to the solution reads. “If we deflect 1.8% of incident solar radiation before it hits our planet, we could fully reverse today’s global warming. The bubble array would be made of inflatable shields of thin silicon or another suitable material, according to the team. The bubble cluster would be placed in outer space at a Lagrange Point, where the Sun’s and Earth’s gravitational pulls create a stable orbit. The researchers also said that if the plan becomes a reality in the future, the completed array would be roughly the size of Brazil.

 

They admitted that one of the main concerns with their proposal would be the logistics of fabricating a large film, transporting it into space, and then unfolding it to form the bubble raft. They suggested fabricating the spheres in outer space to minimize shipping costs.

“[The] bubbles can be intentionally destroyed by breaking their surface equilibrium, this would make the solar geoengineering solution fully reversible and significantly reduce space debris,” the MIT researchers wrote in a statement. They also pointed to the difficulties of maintaining the integrity of the bubble shield. “Effective replenishment rate will be studied to ensure the shield maintains its size, together with strategies to guarantee a smooth end-of-life transition.”

This isn’t the first space-based solution proposed to block the Sun in some way. In 2017, a study suggested an Earth-sized shield to stop solar flares from messing with our communication systems.

 

But why go to such extremes (which surely have unforeseen risks and consequences)? The MIT researchers described the proposed space bubbles as something to supplement other climate change mitigation efforts, but it is still a speculative plan, and other solutions currently exist. If the political will, funding, and technology is available for these high-tech solutions, the same should be possible for much more reasonable solutions, like putting a stop new oil and gas drilling projects.

 

According to the Intergovernmental Panel on Climate Change, we only have a a jarring three-year deadline to curb our emissions and stop climate disaster. Our current fossil fuel infrastructure is enough to push us over that edge, and we can prevent that by keeping the oil in the ground and working to decarbonize our systems.

People in the U.S. are already suffering the consequences of years of emissions. Some of the largest water reservoirs on the West Coast and in the Southwest are drying up. Several states are experiencing a dangerous heatwave right now, and cities all over the country are implementing water restrictions due to widespread drought. We don’t exactly have the time to tinker around in space, hope that it works, and then continue to pump greenhouse gases into the atmosphere.

 

I actually suggested a similar idea several years ago in my Blog (Larry Simpson’s Thoughts and Musings), based on an article by a graduate student.

 I copy my old Blog posting below.

“Dr. Lagrange Would Be Smiling

 

In the late 1700's, the mathematicians, Leonhard Euler and Joseph Lagrange, discovered that there are five points where the gravitational attractions of two astronomical bodies exactly cancel out. Actually, due to the elliptical orbit of the earth, these are "areas" rather than points. A diagram of the five Earth-Sun Lagrange sites is shown below (from Wikipedia).

These sites are not just of academic interest, but may actually be the saviors of the world! This is a rather presumptuous statement, even for a molecular biologist like myself, so let me try to explain. In 1958 the Polish astronomer, Kordylewski, observed the presence of large very faint clouds of dust at two of these Lagrange sites. And of course there have been many science fiction books using Lagrange sites for a variety of fantastic operations..

 

And now the plot thickens. A few months ago I read an article about a proposal by Russel Bewick, a graduate student, and his collaborators in a paper in the Journal of Space Sciences which is a respected journal. They propose to drag a fairly large asteroid such as Ganemede 1036 to the L1 Lagrange point, and to attach a “mass-driver” to generate huge clouds of dust. These would encompass around 1600 km and would be prevented from wandering off by the gravitational pull of the asteroid. Bewick calculated that this cloud could produce a 1.6% reduction in the sunlight reaching the earth, too little to be actually detected by eye. But enough to decrease the temperature of the earth by around 2 degrees C and eventually ameliorate the effects of global warming.

 

When I read this I said to myself that this is a great idea but not feasible. The technology does not yet exist and the possible dangers abound such as making an error (ie using English and not Metric units, as was actually done for a Mars lander some time ago!) and thereby letting the asteroid hit the earth and destroy 90% of the life as happened 60 million years ago in the Yucatan. But by the time we have this technology the accumulative effects of global climate change may be so horrible that this may be a chance worth taking to save our civilization! “

 

In fact NASA has actually proposed an asteroid capture project for developing a way to nudge the asteroid and eliminate the possibility of it hitting the earth. The same method could possibly be used to capture a large asteroid and move it to the L1 Lagrange point. Of course decreasing the heating of the ocean would not solve all the other problems of climate change, such as acidification of the oceans and melting the ice in the artic and Antarctic and causing droughts and flooding. But it may be a start.