Parasols in Space

When I hear the word “parasol,” I think of a woman in a shirtwaist and long skirt, walking down a handsome urban boulevard circa 1890. A charming image. So when I saw the New York Times’ headline “Could a Giant Parasol in Outer Space Help Solve the Climate Crisis?" I was intrigued enough by the contrary images to actually click the link.

From the article I learned that, because (they say) the earth is on the verge of overheating, there are actual scientists who think it might – might! – be possible to put something like a giant parasol up in space to shade us from the sun as we stroll through our days. If you get into the spirit of the thing, this is a bit intriguing. How would you get a “parasol” into space, positioned, and secure enough to provide ongoing shade? Turns out, that critical piece of this thought experiment remains unclear. Perhaps because everyone involved was being playful with the science, the reporter’s byline got cute too. It read “Cara Buckley reported from Earth, specifically New York.” 

She opens by calling the idea “the equivalent of a giant beach umbrella, floating in outer space.” About that shade scientists want to generate, Buckley reports that “scientists have calculated that if just shy of 2 percent of the sun’s radiation is blocked, that would be enough to cool the planet by 1.5 degrees Celsius, or 2.7 Fahrenheit, and keep Earth within manageable climate boundaries.”

Something like this?

That 1.5 degrees Celsius is a magic number. It is the number that the climate obsessives claim the earth is predicted to warm, if we don’t do enough to control the climate. Everything they recommend is geared to counter that allegedly dangerous 1.5 degree rise -- even though the temperature on any given day in almost any given place on the planet rises or falls by that all the time. What you can definitely say about this path to cooling, is that at least it isn’t the same old carbon minimizer. You could have your parasol and your gas stove.

Just kidding! We’d have to do all the other stuff too – give up fossil fuels, gas cars, all the stuff we need for a robust economy, in addition to putting these shade makers in outer space. Because “there’s already excessive heat-trapping carbon dioxide in the atmosphere.” Spoken like a True Believer.

So how do the parasols work? 

One suggestion, from scientists at the Massachusetts Institute of Technology, is to create a shield made of “space bubbles,” whatever they are. An astronomer at the University of Hawaii, Istvan Szapudi, wants to tether a big solar shield to an asteroid. Which is very science fiction-y. How, exactly, would you chain the shield to an asteroid? How would you program the asteroid to stay on a useful path around earth? Because of its weight, launching such a shield is still far beyond today’s technical possibilities. In Israel, the physicist who leads the Asher Space Research Institute at the Technion-Israel Institute of Technology, says his team is ready to build a prototype “to show that the idea will work.”

Of course, to work, the shield that Yoram Rozen has in mind would have to be about a million square miles big. That is the size of Argentina. It would weigh at least 2.5 million tons. Rozen thinks the answer is to employ smaller pieces, which would cast diffused light onto the earth, instead of entirely blocking the sun. He also thinks a prototype could be a mere 100 square feet, for which could be funded at a mere $20 million. Does anyone think that, whatever small prototype emerges, it will ever be possible or cost effective to launch a million square miles of parasol into space?

That’s just a drop in the bucket of ultimate costs, of course. The full model has lightweight solar sails attached to small satellites and would be sent to L1, the point between the Earth and Sun with an uninterrupted view of the sun and currently home to the Solar and Heliospheric Observatory Satellite. Then it would “move back and forth between L1 and another equilibrium point, with the sail tilting between pointing to the sun and being perpendicular to it, moving like a slats on a venetian blind. This would help keep the satellite stable and eliminate the need for a propulsion system, Dr. Rozen said to the New York Times. This model costs trillions of dollars. More than any country could afford for an experiment.

Worked for fireman, back in the day.

The Times article quotes several other scientists at serious institutions who have ideas about space parasols. Some of them have been working on them for two decades. But then the reporter slips in one little negative opinion, in the name of reportorial balance: 

Susanne Baur, a doctoral candidate who focuses on solar radiation modification modeling at the European Center for Research and Advanced Training in Scientific Computation in France, [believes that] a sunshade would be astronomically expensive and could not be implemented in time, given the speed of global warming.

Also it could be damaged by solar storms or collisions with space rocks. 

So, we’re back to giving up our cars, our ovens, air conditioning, steaks, and most of the good things about life in the modern Western world, in order to reduce carbon emissions and get that temperature down by the requisite 1.5 degrees Celsius. What'll they think of next?