Secondary Effects

Ready or not, here they come

One challenging source of CO2 emissions is long-haul “maritime transport” (ships), responsible for around one billion tons of CO2 per year. No one is volunteering to build mid-ocean charging stations, so battery-powered ships appear impractical. Carbon-free shipping is a sufficiently difficult problem that reasonable people are thinking about ammonia-powered ships and spinning metal sails. But! It turns out that 40% of all goods transported by ship are fuels. So when we phase out fossil fuel use in the economy overall, almost half of shipping emissions will vanish as a happy side effect.

Public companies, including oil giants like ExxonMobil, Shell, and BP, are under increasing pressure to reduce carbon emissions. As a result, many are simply selling their dirtiest assets to owners with fewer disclosure requirements. Instead of being shut down, these projects are winding up in the hands of new owners who lack accountability and may not bother to run them even as cleanly as the oil giants do.

As electric vehicles take over more of the market, gas stations may start to close, making gasoline cars less convenient and accelerating the move to electrics.

Increased adoption of solar power in California yields a flood of electricity supply at midday. Then solar production drops off in the evening, just as demand peaks. This puts serious strain on the electric grid, known as the “duck curve" because of the shape of the usage graph (seriously, it does kinda look like a duck).

What do these stories have in common? They’re all examples of secondary effects.

Did You Want Brownouts With That?

Secondary effects, also known as “second-order effects”, are the indirect effects of an action. I found an excellent blog post on the topic, which defines the term neatly:

To first order, every action has a consequence. To second order, every consequence has its own consequence.

So, secondary effects are consequences of consequences. They are worth calling out because, being indirect, we often fail to account for them. Secondary effects can be good (phasing out coal reduces demand for shipping) or bad (solar power straining the grid). But they’re never optional. When you buy the plentiful daytime electricity, they throw in the evening power slump for free.

Plan For Secondary Effects

Because secondary effects are unavoidable, we need a plan for addressing the undesirable ones. Sticking with the rooftop solar example:

• As I discussed last time, solar homes break the traditional utility financial model, because they use much less billable electricity but utilities still incur substantial costs to support those homes. We need to decide how to pay for those ongoing infrastructure needs.

• The wild “duck curve” swing from solar-drenched afternoons to peak-electricity-demand evenings strains electricity supplies. We need batteries or other storage to smooth things out.

Proponents need to anticipate these issues, and lay the groundwork for friendly solutions. Otherwise progress may stall, or unfriendly solutions may arise.

People gravitate toward simple stories, so secondary effects often get insufficient attention. Rooftop solar panels are a simple, appealing idea. Upgrades to the electric grid to support power flowing in different directions at different times of day are a lot less sexy.

Secondary Costs and Benefits Still Count

Secondary effects can impact the cost / benefit analysis of a decision. For instance, emissions from maritime transport are important… but if we believe that phasing out fossil fuels will eliminate the 40% of maritime transport devoted to shipping fuels, perhaps it pushes this particular emissions source down the priority list. Or perhaps it tips the calculus to the point where we can reasonably get by with measures that merely reduce fuel usage (those rotating metal sails) rather than migrating away from carbon-based fuels entirely (ammonia power).

It’s important not to get so emotionally attached to a plan that you’re blinded to its secondary effects. Planting trees, of course, has a primary effect of pulling carbon out of the atmosphere. But as I noted a while back, there’s an important secondary effect: forests often absorb more heat than unforested terrain, and can actually make warming worse. It’s hard for many people to wrap their heads around the idea that planting trees isn’t an all-purpose solution to climate change; but there really are good reasons to question this.

Secondary Opportunities

Some secondary effects create opportunities. The duck curve is a problem in the evening; but during the day, it represents a plethora of cheap power. We could use that to desalinate seawater, creating hydrogen fuel, and lots more.

Don’t Overthink It

So long as we’re on the subject of second-order effects, I can’t resist including the recently coined Zeynep’s Law:

Until there is substantial and repeated evidence otherwise, assume counterintuitive findings to be false, and second-order effects to be dwarfed by first-order ones in magnitude.

In other words, while it’s important to consider secondary effects, avoid the temptation to get carried away by too-clever-by-half analysis. Zeynep was speaking in the context of coronavirus response, where public officials often seem to act on overwrought logic like (early in the pandemic) “we shouldn’t tell people that masks are helpful, because they’ll buy up all the supply”. But the same thing happens in the climate field: “if we develop techniques for removing carbon from the atmosphere, fossil fuel companies will use that as an excuse to keep pumping oil.” Sure, they might try that, but they’re going to look for excuses anyway; and we really do need ways of drawing down carbon. Abandoning a critical line of research because of a questionable secondary effect is not a proportionate response.