We’ve heard it over and over again.

Young people are worried about the climate. Young people suffer more from mental health problems than prior generations – and these two things may be connected in some way.

That’s at least what earlier studies have suggested. 

Therefore, it was quite a surprise to Dan and Katie Major-Smith, two of the three researchers behind the new study, that they didn’t find an association.

- We were kind of shocked, actually. I’ve worked with climate research for some years now, and I’ve met a lot of activists and other concerned people, who are very much affected by the lack of climate action, Katie Major-Smith explains.

Her husband Dan, the data cruncher of the two, adds:

- The results were surprising, but we shouldn’t get carried away. We don’t have very good data on climate anxiety. What we have is measures on climate concern and that is not necessarily the same as anxiety.

- If we did the same study, but had data on climate anxiety as well, I think the results would have been quite different.

Earlier this year Dan and Katie Major-Smith relocated to Aarhus University. They both grew up in England and have lived there most of their lives, except for a stint or two in the Philippines for research purposes.

They’ve chosen very different research fields which tend not to overlap. Dan’s an evolutionary anthropologist who later specialized in epidemiology. Katie is a social scientist researching sustainable food.

But one day the opportunity to collaborate arose.

- In Bristol, where we used to live, I worked with data from the Avon Longitudinal Study of Parents and Children – colloquially known as the ‘Children of the 90s study’. It’s a big study spanning 30 years. In the early 1990s researchers recruited over 14.000 pregnant women and have followed both the women and their children since. In some cases the study spans three generations now.  

- With this data I got the idea to look into climate concern and mental health. I hadn’t done much climate research before, so I asked Katie to help.

Katie brought in the climate change expertise and helped with framing and introducing the study. Dan did the data crunching.

- It was fun to do something together and I always think it’s rewarding to bring in new perspectives from different fields, she says.

When Dan and Katie sat down to outline the study, they had two burning questions they wanted an answer to.

Firstly, they wanted to know if climate concern directly affects mental health. Most prior research has found a link – an association – but inferring any causal relationship has been difficult. They wanted to explore, if that was possible.

- There’s a lot happening in the research field on climate anxiety and concern at the moment. But we still don’t know which direction the association between climate concern and general mental health goes. Do people get climate anxiety, because they already have mental health issues, is it the other way around or perhaps it goes in both directions, Dan says.

The data from the ‘Children of the 90s’ study is quite unique, as the researchers have repeatedly collected data on the participant’s mental health and climate beliefs. 

With longitudinal data like this it’s possible to spot if there is a causal relationship because it’s possible to monitor how both mental health and climate concern is evolving over time. 

Imagine Dan’s surprise when they didn’t even find an association.

- It was disappointing in a way. But also interesting. Maybe this population just isn't worried about the climate to a degree that affects their mental health.

The other question, they wanted answered, was whether the impact of climate concern on mental health was alleviated by engaging in climate action. But again they found no effects.

- We wanted to know if, among those concerned about the climate, planting trees or using more public transportation for example has an effect on people’s climate concern. To me it would make sense, if doing something, being part of a movement trying to change things would help. But again we found no effect, Katie says.

We don’t know why there’s these differences. There’s a lot of unanswered questions that I hope will be addressed in the future, Dan says.

- Dan Major-Smith, postdoc, Aarhus University

The Children of the 90s participants whose data were used in this study are all around age 30 now. Their age could explain why Dan and Katie found no effect from climate worry on mental health.

- Most research has studied people a lot younger. Typically they are under 25 and more engaged in the climate movement. This might explain why we saw no effect here. But we can’t know for sure, Katie says.

The age-difference is one of several open questions on this topic. Why do the researchers observe these age differences? Is it a generational difference? Coming of age in a slightly political climate? Or what could be the explanation?

An explanation of why this study did not find a relationship between climate concern and mental health could be the way the data was collected. The study measured climate concern which is much less extreme – and hence not directly comparable – with climate anxiety.

- We therefore need similar longitudinal research that instead explores the impact of climate anxiety rather than just climate concern on mental health, Dan says with Katie adding:

- I hope that future research will provide a better understanding of the link between climate anxiety and mental health and help people who experience these symptoms. 

Other new studies also seem to show that there are differences between European countries. In some countries the young people are more worried about the climate and researchers find an effect on mental health. Whereas in others they can’t find it.

 - We don’t know why there’s these differences. There’s a lot of unanswered questions that I hope will be addressed in the future, Dan says.