So many of the things we think and do are founded on cultural memes rather than rationality. Australian architecture is still imbued with cultural memes derived from England, whose housing designs evolved in a totally different climate. Another example is the wearing of long-sleeved shirts and ties. In the 17th century, in a temperate climate with inadequate thermal insulation for buildings, it was practicable - to keep body heat in - to cover the arms and fasten the neck with a woollen scarf as worn by the Croatian military. This fastening became known (probably after the Old Slavic word Chǔrvatinǔ for "Croat") as a "cravat", the ancestor of the modern necktie.

The slowly-growing public and political awareness that hydrocarbon reserves are not unlimited is tempered by the more immediate economic reality that renewable enrgy sources are, as yet, more expensive in the retail market. And the meme of the personal automobile as a statement of personality or personal success is still firmly entrenched, an entrenchment exacerbated by a lack of adequate public transport in some countries.

The combination of cultural memes, current-market economic realities and the pyschological distance to 'over-the-horizon' projected consequences of current practices, means that renewable energy advocates still face an uphill task to persuade policy-makers to make radical changes to legislation and public infrastructure investment.