At one point, mischievously, I made the suggestion: "Look, wouldn't it just be cheaper and easier to legalise cannabis?"
Well, think about it. A glance at national rankings of greenhouse gas emissions per capita shows Jamaica well down the list, with half the per-capita emissions of the UK. In hedonistic terms, the economy of Jamaica seems far more efficient than our own, consisting almost exclusively of economic activities that contribute directly to human happiness: music, brewing, cricket, hospitality and drugs. By contrast, little effort seems to be consumed by the vast parasitic meta-economy you find in Anglo-Saxon countries: lawyers, accountants, hedge-fund managers, holding companies, women's shoe shops - that kind of Babylonian nonsense.
My assertion is that, if you legalised cannabis in the UK, the short-termist, pleasure-seeking culture this would create would soon reduce our emissions by 50 per cent - an achievement beyond George Monbiot's wildest hopes. Emissions from aviation would fall dramatically, since we'd never be able to remember where we'd left our passports. And fuel companies would be able to get out of the oil business altogether as they'd make far more money selling Mars bars from late-night forecourts. It's true GDP would fall but, as no-one would bother to collect the figures, we wouldn't much care.
An improbable solution, perhaps. But I am using it to make a serious point: in order to make people behave in an environmental way, it is not necessary to make them environmentally aware - or even to consider the environment at all. All you need do is stage an intervention of some kind, which will result in more environmentally friendly behaviour.
Most marketing briefs proceed from the assumption that a direct attitudinal change is both a necessary and a sufficient precursor to behavioural change. That in order to make people behave in a more environmental fashion, you must first arouse in them the conscious desire to become greener. Most creative briefs are written from this assumption.
Sometimes this might be right. But it is wrong to approach briefs as though this were the only answer. Attitudinal change is sometimes neither a necessary nor a sufficient precursor to behavioural change. Yet few ad campaigns attempt a second-order approach to problem-solving - "chuck out your chintz" is one of very few I can think of. You can sell more Coke by getting people to want more Coke. But you can also sell more Coke by getting people to buy more ice.
- Rory Sutherland is the IPA president and vice-chairman of Ogilvy Group UK.