How Effective Are Different Climate Interventions?

My friend, Mariah Howard, shared this CNN.com climate change solutions quiz today. It’s based on data from Paul Hawken’s excellent climate nonprofit, Project Drawdown. I took the quiz, and it nicely confirmed what I suspected: Other than the consequences of a mostly plant-based diet, I had very little clue about the actual impacts of most proposed climate interventions.

I’d like to see more exercises and visualizations that accomplish this for all sorts of problems. Skilled systems thinker don’t think in terms of binaries. They ask questions like, “How much?”, and, “In exchange of what?” Knowing that driving a Prius lowers my carbon footprint isn’t useful if what I actually care about is getting overall atmospheric carbon below 350 parts per million. (We’re currently at 412 and growing.) What matters is how much it lowers my carbon footprint.

That said, there were a few things I didn’t like about the quiz. First, the scoring system doesn’t make sense. (I scored 34.4 percent overall.) You’re asked to rank a set of interventions based on carbon impact. As my friend, Travis Kriplean, pointed out, if your three interventions are ranked 1-2-3, and you rank them 1-3-2, you’re penalized the same as if you ranked them 3-2-1, which is a more egregious error.

Furthermore, the rankings alone don’t tell the whole story. If intervention 1 will remove 10 gigatons of carbon from the atmosphere, intervention 2 will remove 2, and intervention 3 will remove 1, then mixing up 2 and 3 wouldn’t be egregious, whereas not ranking 1 first would be a huge miss.

Second, CNN.com tries to show which interventions can be implemented by individuals versus industries and public policy. For example, eating a plant-based diet is labeled as something that individuals can do, whereas investing in high-speed trains is something that requires policymakers. I don’t find this to be a helpful distinction. Sure, I could switch to a more plant-based diet, but policymakers could also end meat subsidies, which would raise the price of meat and consequently lower a lot of people’s meat consumption. On the flip side, the quiz labels more walkable cities as a public policy intervention, but it could just as well as have made it an individual intervention where a whole lot of people simply walked more.

This problem is exacerbated by the quiz attempting to make the impact more tangible by showing the equivalent number of gas guzzling cars taken off the road by each intervention. This is an admirable goal, but it makes no sense in the context of this particular exercise. For example, it claims that “driving an electric car” — an individual intervention — would be similar to taking 75.7 million cars off the road. No, actually, if I drive an electric car, that would be similar to taking one gas-guzzling car off the road. If you read Project Drawdown’s analysis, they make projections based on EV’s taking up 16 percent of total passenger miles by 2050. The details here matter.

All that said, the quiz caught my interest enough for me to go down a little bit of a research rabbit hole, something I’ve been wanting to do for a while but have never gotten around to doing. I also learned some surprising things. I’d encourage others to give it a try.

For more on these drawdown strategies, Travis recommends watching Chad Frischmann’s TED Talk: