I am pleased to announce that I won an award for an article I wrote!

Every year, the Solar Physics Division of the American Astronomical Society (the largest group of professional astronomers in the US) gives out a slate of awards for science communications, called the Popular Media Awards. This year, I won for my article, “Could the Sun Fry Earth with a Superflare?” published on May 2, 2025. 

The category was for scicomm done by a scientist, which, fair enough. I’ve never really been able to categorize myself — I’m not really a journalist, and I haven’t done scientific research in a while. So I just think of myself as a scicommer.

I got a smile, too, that I won for an article about our planet getting cooked by a cosmic disaster; that’s kinda my thing.

My thanks to everyone on the award committee! It’s an honor, and I truly appreciate it.

Earth is warming up, changing our climate drastically, and not in a good way. Hurricanes get more powerful, tornados do more damage, we get rain and drought and sea level rise and ocean acidification and you get the idea.

What can we do about it? One idea is to somehow make Earth’s atmosphere more reflective, so we don’t get as much incoming sunlight. Less light = less heat = less warming. This is part of a category of ideas called geoengineering, where we change something about the planet to mitigate warming.

One of the ideas is called stratospheric aerosol injection, or SAI. Aerosols are particles that can be suspended in air, and the stratosphere is the layer of our atmosphere that starts roughly 10-20 kilometers above the ground (depending on latitude) and goes up to about 50 or so km. “Injection” seems obvious enough: the idea is to dump a lot of teeny particles of some substance into the air that then remain suspended in the stratosphere, reflecting sunlight.

There have been quite a few studies about this, and some people take the idea seriously. But a study has come out showing that the effects of this are difficult to predict, and the outcomes make it risky [link to journal paper].

Now, on a zero-to-duh scale I’d rate this conclusion as about a 15. We really don’t understand geoengineering at all, and we do know that a lot of effects are non-linear; that is, you change a small thing and it can affect multiple other things, which then affect even more other things, and you wind up getting an outcome you can’t predict and that can be wildly different given small changes in the input.

But this paper actually outlines a lot of real-world problems with SAI. For example, what do you use to reflect sunlight? Some kinds of tiny grains are expensive, and you need so much (millions of tons!) that it can affect the market, ramping up prices. Others are easier to obtain, but their actual properties make them harder to use; they can clump up, for example, increasing the grain size and reducing their reflective properties.

Another problem is that, as you’d expect, there are unexpected effects. For example, volcanic eruptions put a lot of sulfur aerosols into the atmosphere, and we’ve seen temporarily cooler temperatures from that (like after the Pinatubo eruption). However, this can change rainfall amounts in various locations, and even affect the ozone layer. Polar injections can cause changes in monsoons. Sulfur eventually dropping down can cause acid rain as well.

My worry about this on the theoretical side is that it’s impossible to model all the effects, especially on the biosphere. Non-linear effects, especially in Earth’s atmosphere, are ridiculously sensitive to even small changes, and the equations are fierce. There are always unintended consequences, and they might be mild, or they might be catastrophic.

My worry on the practical side is that some dunderheaded egotistical billionaire might just decide on their own to go ahead and do this, and it winds up being a catastrophe, because any time a billionaire gets it into their heads to do something like this it always is.

To be clear, I am against using our only planet as an experimental lab. 

The flip side of this, though, is that we already do. We’ve been running a decades-long experiment of dumping billions of tons of carbon dioxide into the air annually, and we know how that’s turning out. Don’t let the climate science deniers fool you: global warming is 100% our fault.

So sure, especially given we’re the cause, it seems like doing something to mitigate this is a good idea… but this ignores the incredibly obvious idea that WE SHOULD STOP RUNNING THE EXPERIMENT. We need to decarbonize our energy production and stop the greenhouse gasses from getting into the atmosphere in the first place. This won’t reduce the problem — and least not for a long time, since CO₂ has a long half-life in the atmosphere — but it will stop it from getting worse. Then perhaps we can start doing something to reduce the amount in there.

And also to be clear, I am all for investigating geoengineering in a theoretical sense; let’s talk about and scientifically analyze different ways of reducing CO₂ or reflecting sunlight or whatever, but let’s do it in a sober, judicious way, and not run off half-cocked and potentially make a serious problem even worse.

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