Why Everyone Disagrees About Climate
It's Complicated, And it Won't Stand Still
You can’t spend more than 10 minutes reading about climate change without running into opposing claims. I’m not even talking about denialism or politically motivated positions. I’m talking about well-intentioned, serious folks confidently saying contradictory things.
For example, it’s a commonplace that the industrial sector will be a major stumbling block on the road to zero emissions. Here’s a typical framing, from the Brookings Institute (emphasis added):
Steel, cement, and chemicals are the top three emitting industries and are among the most difficult to decarbonize, owing to technical factors like the need for very high heat and process emissions of carbon dioxide, and economic factors including low profit margins, capital intensity, long asset life, and trade exposure.
Sounds reasonable, no? “Very high heat”, hmm, yes, obviously difficult. “Process emissions”, I don’t know what those are, but they certainly sound serious1.
Meanwhile, Canary Media reports (emphasis added):
…the options to reduce the carbon-intensity of concrete … are broadly available, practical and cost-effective today, building decarbonization experts say.
And in fact, a variety of companies are developing carbon-neutral or even carbon-negative cement. As for steel, an interview earlier this year, Rebecca Dell of ClimateWorks notes that there are several strong contenders for decarbonization: substituting hydrogen for methane in "direct reduction”, or switching to one of several electricity-based approaches. Modest shipments of carbon-free steel have already begun. Maybe the industrial sector isn’t so hard to decarbonize?
And of course this isn’t the only topic where opinions diverge. Reforestation, agricultural carbon sequestration, shipping, scaling mineral production, the role of geothermal and nuclear power, grid stability, viability of hydrogen… it’s almost harder to think of a major topic where there isn’t widespread disagreement.
If this leaves you confused, you’re not alone. I’m right there with you.
Some Contradictions Vanish On Closer Inspection
In the example above, we have some people saying that the industrial sector is “hard to decarbonize”, while other people are busily decarbonizing it. That’s not actually a contradiction2! Heavier-than-air flight was legit “hard”, but we’ve gotten pretty good at it.
It’s easy to lose track of the fact that divergent viewpoints may not actually contradict, because messages tend to get simplified into sentiments like “cement is a problem” vs. “cement is not a problem”. The truth is usually in the messy middle: cement is a solvable problem, if we put in the work. If you look for simple answers, you’ll wind up with contradictions.
Failing To Allow For Change
Heat pumps have a reputation for struggling in cold environments, because historically, they did struggle. However, Consumer Reports recently reported3:
But that’s old news. When properly installed, plenty of today’s air-source heat pumps… can keep your home toasty even amid bone-chilling cold, using far less energy than other types of heating systems.
The article goes on to note that a poorly designed installation can still have problems. So: do heat pumps work in cold climates? In the past, no; today, yes; but only if done properly. There are lots of people who “know” it’s a problem because they aren’t up on recent developments, or had a bad experience with a bad installer. Others have had good experiences. People in either situation will happily share their views, and don’t always do a good job of clarifying the scope of their knowledge.
Similarly: the costs of solar, wind, and battery power have been plunging. Myriad other technologies are moving from idea to lab to pilot project. The facts keep changing, and people don’t always notice, or don’t update their views to reflect the implications.
It’s hard enough to keep up with the changes that have already happened; projecting forward is even trickier. For example, we’re likely heading toward an era where electricity will be super-cheap if you’re willing to be flexible in your consumption. (“Flexible” meaning locating near good sources of renewable energy, shutting down when solar + wind aren’t running, etc.) There are proposals to use this cheap, intermittent power for energy-intensive processes such as desalination or hydrogen production. Someone who hasn’t internalized the idea that tomorrow’s grid may look very different from today’s, will write off these ideas as uneconomic.
An oft-stated example that really bugs me: “EVs don’t help because we still use coal power on the grid they charge from”. The vehicle transition and the grid transition are both necessary, and the best thing is to run both transitions in parallel, so that we converge as soon as possible on all-electric vehicles on a zero-carbon grid.
Over-Generalizing
Another way contradictions can arise is when people over-generalize from limited experience: “My solar roof worked out great, so solar can solve everything.” (Try getting through an Alaskan winter on nothing but solar power.)
Another favorite is extrapolation from one flawed proposal to write off an entire field: “batteries don’t have the energy density to carry an airplane more than a few hundred miles, so we can’t decarbonize aviation”. (Aviation really is a challenge, but hydrogen power, atmosphere-derived fuels, and other approaches hold promise. We don’t need to use batteries for everything.)
A common mistake is failing to allow for scaling limits. For instance, singing the praises of hydropower, without noting that it can only be used in specific locations; or of planting trees to draw down CO₂, when there isn’t enough suitable land to solve the entire problem4.
How To Navigate the Maze
Spoiler: it’s hard!
The first step in resolving contradictory claims is to move past the headline and dig into the underlying arguments. What data is each author drawing on? What is their argument, and what exactly is their conclusion?
Then you can start to look for ways of resolving the apparent contradiction:
When framed carefully, do the conclusions actually contradict?
Is either author working from stale, suspect, or anecdotal data?
Are their arguments sound? Is this good-faith, objective analysis? Or is one source relying on motivated reasoning?
Does either author directly address the opposing argument? Is the rebuttal valid?
Which argument aligns with your understanding of broad trends?
We Need Less Monologue and More Dialogue
When two domain experts5 contradict one another, it's a challenge for the lay reader – that's me, and (statistically speaking) you – to sort things out. It would be great if the experts could hash things out directly!
Unfortunately, this doesn’t seem to happen very often. On the My Climate Journey podcast, Jason Jacobs has been making an effort to bring in divergent viewpoints, which is a nice start.
It’s also just hard to keep track. Suppose I read a thorough discussion of whether steel manufacturing is “hard to decarbonize”. Then next month I’m reading about the steel problem again. I may not remember the previous discussion well enough to know whether it addresses the points made in the new article.
In my fantasy world, there would be a sort of living Climate Tech FAQ, recapping the relevant facts and common opinions on a broad range of topics, and able to serve as a cheat sheet – where is there expert consensus, what ideas have been superseded (or debunked), which seeming contradictions are just issues with framing or terminology, and where are there legitimate open questions. And since I’m fantasizing here, the site would sponsor thoughtful long-form discussions to help reconcile divergent views.
In the real world, the only advice I have is to apply good ol’ critical thinking skills, as discussed above. In particular, because things change so quickly, always be on the lookout for over-generalization, overly broad claims, and arguments based on stale data.
OK fine, actually I’ve learned this one, “process emissions” are emissions that are a natural part of a process, rather than a side effect of burning fuel. In particular, to make cement, we start with limestone, which is basically calcium carbonate. We need the calcium, and the carbon is left over and (after the chemical processing is done) winds up in the form of CO₂.
Dell goes on to argue that the industrial sector is not really harder to decarbonize, we just haven’t done the work to decarbonize it yet. (Electricity was also “hard to decarbonize” until we spent billions developing wind, solar, and batteries.)
What, you expected me to say “Consumer Reports wrote”? Obviously they reported. That’s what they do. That’s all they do.
Not to mention the many other issues with reforestation as a solution to climate change.
Hopefully.
What do you think of Project Drawdown? I found it a good summary of possible solutions, could it be something that works for the last part of your article?
It should be Brookings, not "Bookings"