‍This one turned out quite long, but this is still a written-all-at-once first draft. I might edit it properly and turn it into an essay. I reserve the right to change my mind or articulation of anything below.

I started my career, way back in 2010, as an intern at the Royal Society, which is the UK’s national science academy. 

It was an incredible experience for many reasons. We interns were shown various treasures in the library, like the manuscript copy of Newton’s Philosophiæ Naturalis Principia Mathematica, I organised a conference where I met Naomi Klein, among others, and I swam in the choppy waters of a topic that even today is controversial: solar geoengineering.

Let me start with some science before I turn to the more important matter of what’s allowed in public discourse.

Solar geoengineering is the intentional reflection of sunlight into space to moderate some effects of global warming. At the sci-fi end of the options is the deployment of tens of thousands of tiny mirrors into space between the Earth and the Sun. But that’s expensive and probably silly.

More sensibly, we could do it by increasing the Earth’s surface albedo (reflectivity), say by painting buildings white, by covering dark landscapes with a light-coloured material or by making marine clouds brighter with special ships that turn seawater into a fine mist.

We could also inject aerosols into the stratosphere with planes or high-altitude balloons to replicate the global dimming effect of volcanic eruptions. Did you know that when Mount Pinatubo erupted in 1991, the 20 million tonnes of sulphur dioxide it released reduced global temperatures by 0.5ºC for two years? It could be worse; when Krakatoa exploded in 1883 the material it released reduced global temperatures by 1.2ºC and had a century-long impact on ocean temperatures. 

All this to say, we know how it works and that it works. It would also be quite cheap, all things considered, maybe $18 billion per year per ºC of cooling. Given this, let’s assume that when people say solar geoengineering they mean stratospheric aerosol injection.

Now the obvious question: if stratospheric aerosols can definitely reduce global temperatures for cheap, why aren’t we doing it or even planning to do it. Ah yes, the downsides.

First up, it does absolutely nothing to change the amount of carbon dioxide in the atmosphere, which would continue to rise if we don’t reduce emissions. So while average global temperatures may be held down, other effects of increasing atmospheric carbon dioxide, like ocean acidification, would continue.

It’s likely that solar geoengineering would disrupt global weather patterns. We’re talking droughts in some places, flooding in others, crop failures and the like. Oh, and injecting aerosols into the stratosphere could turn the sky white. 

It would also disproportionately affect developing countries, which are least responsible for the emissions that have driven global warming, are least able to invest in their own resilience and have the least influence on the global stage. But this is a complex area. If you’re a small island state facing obliteration from rising sea levels, you might support measures that promise to keep sea levels down.

Finally, there’s the risk of moral hazard. Do you drive a fully insured rental car as carefully as you drive your own? Similarly, if you know you can just turn the sun down a bit, are you as motivated to decarbonise our civilisation as fast as possible? This is the risk I see talked about most often and, as you'll see below, I think often unhelpfully.

Fundamentally, solar geoengineering is a terrible idea that we shouldn’t have to even vaguely consider. Yet it seems that the impacts of global warming may actually be worse than solar geoengineering, so here we are. To let that sink in, I’ll quote my friend Andy Parker, who was my manager at the Royal Society, who is now Project Director for the Solar Radiation Management Governance Initiative, and who, disclaimer, has not read or ‘approved’ of anything in this note:

“We live in a world where deliberately dimming the fucking sun might be less risky than not doing it.” 

I think in most places this is quoted as “deliberately dimming the <expletive> sun”, but I have it on good authority that said expletive was fucking. You’re welcome.

Alright, enough of that. Solar geoengineering is a stupid thing to do that may look quite sensible if we continue on the lacklustre path we’re currently on. Let’s turn to the actual point of this note, which is about the vital need to be able to talk about this topic, and others like it, in a sensible way.

You may have heard the terms climate mitigation and climate adaptation. Mitigation means all the things we can do to reduce new emissions into the atmosphere. This means renewable energy, reducing energy demand, flying and driving less, all that stuff. Mitigation is probably 95% of what you think of when you think about fixing global warming.

Adaptation means accepting that we are committed to some level of impact from global warming, let’s say new droughts, flooding or sea level rise, and then doing something about those impacts. This might mean building stronger coastal defences for low-lying regions or investing in more sophisticated irrigation systems. It might mean creating new insurance products for farmers, developing extreme weather warning systems or even non-coercively relocating entire communities.

Being able to talk about adaptation means being able to tolerate the paradox implied in the moral hazard. Yes, we are talking about building flood defences, but that doesn’t mean we have to invest less in mitigation efforts like renewables and energy efficiency. You can choose to sail your leaking boat back to shore while also bailing water out of it. 

I mean, in theory, anyway. In practice, talking about adaptation was frowned upon, even in academic circles. Even in 2013, there are references in the scientific literature highlighting that discussion of adaptation was, until recently taboo: 

Until recently, adaptation — a process by which societies address the consequences of climate change — was a taboo subject in the discussion of global climate policy, where it was viewed as undermining efforts to reduce greenhouse gas emissions (see Pielke, Prins, Rayner, & Sarewitz, 2007). However, the realization that, even in the best-case scenario, emissions reductions can have little effect on social vulnerability to climate impacts over the next several decades has prompted a resurgence of interest in adaptation” — Stephanie Amaru, Netra B. Chhetri

Climate adaption is now considered mainstream, although all that means is that the truth of how significant global warming impacts have already become is now unambiguous and unavoidable. You might reasonably argue that if adaptation hadn’t been taboo for so long, we’d have talked about it more and earlier, and so benefited the millions of people around the world who now need to, you know, adapt.

And had we talked about mitigation properly earlier, we may not have needed to talk about adaptation. If we don’t talk about solar geoengineering now, we risk having to do it blind. And if it does turn out that we need to do solar geoengineering, I would prefer the science and governance implications around it to be as good as they can possibly be, because if we do have to turn down the fucking sun, I want it done as carefully as possible.

Whenever I see someone call for more climate action while also denouncing discussion of certain options, I become suspicious of their motives. “We must do everything we can, the world is on fire! Oh, but not that.” Perhaps solving climate change isn’t your top priority after all, then?

If the goal is to avoid dangerous global warming and its impacts then we need all options to be on the table. This is a both/and emergency, not an either/or emergency. Solar geoengineering is the most extreme example of this, but the principle applies as much to such things as carbon removal, carbon capture and storage and even nuclear power.

Being able to have hard conversations about hard choices means we’re more likely to have the conversations early on and thus make navigating the hard choices easier. We need to get better at talking about things that are considered, at least by some, to be taboo. The risks of not talking about something are vastly greater than the perceived fears of that thing happening if we do.

“What is true is already so. Owning up to it doesn't make it worse. Not being open about it doesn't make it go away. And because it's true, it is what is there to be interacted with.” — Eugene Gendlin 

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If you liked this, you might also like these:

• How should we think about carbon removal?
• Different kinds of authority
• An idea cannot exist out of context

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