How many hamburgers does it take to save the planet?

From these results, the authors drew a stark conclusion:

The findings are interesting because they seem to support the ‘old’ way of thinking about campaigning on climate change, which prioritised the provision of information, and relied (often implicitly) on the so-called ‘deficit model’ of public engagement (whereby people would care more, or change their behaviours, when their ‘deficit’ of knowledge was addressed).

More contemporary approaches have emphasised the importance of values, worldviews, social norms and political ideology in determining engagement with climate change, and underpinning meaningful low-carbon lifestyle changes. 

The ‘nudge’ approach (also known as ‘Behavioural Insights’) offers a third route, with a more agnostic take on the role of knowledge (focusing instead on changes in the decision-making environment and avoiding questions of ‘persuasion’ altogether).

But the authors’ take on their findings represents an unusually reductive assessment of people’s agency and ability to make the ‘right choice’. Taking a few steps backwards, away from the study’s findings and looking to the wider context of public engagement, perhaps there is a different interpretation. 

Campaigns have too often focused on ‘simple and painless’ behaviour changes, prioritising plastic bags and coffee cups over more impactful lifestyle shifts around diet and travel. As the authors of the new study note, this creates a strong ‘availability’ bias whereby people assume the actions they hear the most about are more impactful than they really are. So at a minimum, campaigns need to focus on the behaviours that matter – something we discuss in our chapter on lifestyle change in the soon-to-be-released UNEP Emissions Gap 2020 report.

The study found that the accuracy of people’s hamburger vs flight estimations was not driven by how much they cared about climate change (or their political orientation – a good proxy for climate concern in the US), but primarily on basic numeracy. 

Clearly knowledge does matter to some extent. Arguably, the pendulum has swung so far away from the deficit model for some practitioners that there’s a risk that knowledge is discounted altogether. But what kind of knowledge matters? 

Being able to roughly rank the impact of different actions is the kind of knowledge that has practical value, and seems a valid target for campaigner energy. But calculating hamburger-to-flight ratios is something that no one other than climate geeks would need to do.

Carbon labelling is a long overdue development that would certainly help people to make the best possible decisions. But as other social transformations make clear, this approach is necessary but not sufficient for changing behaviours. Over the last decade, levels of smoking have reduced rapidly in many countries around the world – this has been driven not only by labelling (health warnings) but also by shifting social norms and structural changes (laws and regulations). 

Campaigns across policy and advocacy must create the conditions under which it’s clearer (by focusing on the right kinds of behaviour), socially desirable (by promoting positive social norms) and perceived as fair (by mirroring any behavioural changes with structural shifts) to make the ‘right decision’.

That way, nobody needs to calculate hamburger-to-flight ratios to do the right thing.