Currently reading Sinclair et al. (2025) on “Behavioral interventions motivate action to address climate change”

Why do people fail to act against climate change, and what interventions could make them act? That’s what Sinclair et al. (2025) investigate in an “intervention tournament”!

There are several psychological factors that influence both climate change beliefs and behaviours:

• Perceived relevance: Does it seem like climate change will affect me or people I know, or is it something that only happens far away to poor little polar bears that have nothing to do with my lived reality?
• Future thinking: Do we see why we should pay more attention to the long-term consequences than to the short-term benefits?
• Response efficacy: Do we believe that what we can do can actually make a difference to a system as big and complex as climate? Also which actions would be most effective?

Each of these interrelated factors can be addressed through interventions, individually or in combination. But it is important to note that interventions do not necessarily work; some backfire or others only work on certain outcome measures but backfire on others (e.g. the carbon footprint calculators focus overly on individual action to the point that systemic influences get ignored — and maybe, seeing that they were invented by BP, that’s a feature, not a bug?).

Sinclair et al. (2025) conducted an intervention tournament, in which they tested 17 different interventions on 7,624 participants. Their outcome measures were intentions to engage in pro-environmental behaviours, those actions’ perceived impacts, and the intention to share information about climate change. They found interventions that worked towards each of the outcomes, and interventions that work on several psychological factors generally were found the most effective, especially those that focussed on thinking about future outcomes related to the participants themselves or those close to them. The “Letter to Future Generation” intervention, in which participants write a letter to a child they care about (which they imagine will read it as an adult) and describe what they are doing to make sure that child would live in a desirable future, was broadly effective on all outcomes. Sinclair et al. (2025) conclude that “[o]verall, we recommend illustrating future scenarios and emphasizing the personal and social impact of climate change as leading strategies to promote behavior change and information sharing.”

I find this article really interesting, because (I suspect!) interventions — like the carbon footprint thing — are often done by NGOs and other well-meaning actors mostly because they are well-known and easily available, not because they are particularly effective. But now there is a whole bunch of interventions that have been compared against each other, so that makes it a lot easier to take an informed decision on what interventions to run depending on what outcome one is particularly interested in. And especially being aware that interventions can also backfire (although not in this study, since they chose their interventions based on theory and literature about their effectiveness) is very important.

What I am a bit worried about with the letter-intervention is that it feels, at least in my imagination, very intervention-y, so I find it difficult to imagine how it could be done on a large scale without being perceived as brainwashing or otherwise intrusive. It somehow feels too obviously designed to have an effect on people, whereas for example a carbon footprint calculator could be perceived as just informative, similar to some other random information, like how many millimetre of rain fall in a city per day or where stones for a church-build were sourced from. In this study, the participants chosen for this study “reported believing in climate change“, so engaging in an activity like writing a letter (and receiving 5$ for it) might just have been something they do without thinking too much about it. But how would that work out in the wild? Who would search out the activity themselves, or how could people be invited to do it? Possibly in settings where parents come together (like a parent conference at the start of a school year), or at training events for people working with kids (like youth sports instructors), or in other settings where there is a shared concern for people, and possibly also the climate, already. And maybe it is good to do in those settings to work on the outcomes even with people who might be on a relatively high level already, and only start on “the general population” (which, of course, does not exist) in the next step?

Sinclair, A. H., Cosme, D., Lydic, K., Reinero, D. A., Carreras-Tartak, J., Mann, M. E., & Falk, E. B. (2025). Behavioral interventions motivate action to address climate change. Proceedings of the National Academy of Sciences, 122(20), e2426768122.

Images today from a recent swim… I always love breaking waves, but how cute is this little spilling crest?

Glittering sun on water just always makes me happy!

Now I want a swim!