It is often said that those of us who live in affluent, developed counties are 'addicted' to our high-carbon lifestyles, which depend on profligate use of energy and material resources. Think of central heating, air conditioning, our reluctance to wean ourselves off international air travel — whether for business or pleasure — and the amount of meat that we consume in our diets.

Our love affair with the petrol engine is a case in point. In their advertisements, automobile manufacturers often still portray models of cars as outward symbols of male potency, power and career success, or — especially for brands targeted at young women — a penchant for fun and glamour. This is all reminiscent of the way that cigarette brands were once marketed — and to some extent, shamefully, still are in parts of the developing world. Parallels could also be drawn between the way that, in these days of environmental awareness, motor manufacturers increasingly emphasize 'green credentials' such as fuel-efficient engines, with the way that the tobacco industry tried to shift attention to low-tar brands when the evidence that smoking causes lung and other cancers became unassailable.

But it would stretch credulity to push the comparison too far; obviously cars are not 'habit forming' in the sense that cigarettes are, and certainly do not have the addictive characteristics of certain hard drugs. The habit-forming effects of drugs such as nicotine and heroin are mediated by specific receptors in the brain. But it is of course meaningless to talk of a specific 'brain receptor' activated by exposure to a car advert. Nevertheless, it is reasonable to posit that our responses to brands in general, the preferences we develop and the behaviours that we subsequently exhibit as consumers (and more generally as citizens), have a neurobiological basis. This does not at all imply that such preferences and behaviours are deterministically 'fixed', in the sense that they can be modified by learning and experience, or even pharmacologically. If we are sufficiently concerned about the environmental impact of travel, we can by our own volition choose to run an electric car rather than a gas-guzzler.

This seems to be a starting premise of the intriguing new research field of 'neuroconservation', which despite its name has nothing to do with conserving neurons. Rather, as explained by Elisabeth Jeffries (page 776), one of its aims is to study how the brain responds to nature. A working hypothesis is that the way we come to value and appreciate the natural world may involve some of the same brain regions and 'reward' pathways involved in addiction. If that turns out to be the case, which is far from certain, it follows that understanding addiction — both at a neurological and psychological level — might potentially help to devise strategies for shifting people's attitudes in relation to environmental issues such as climate change, thereby promoting climate-friendly behaviours.