In as much as it does not greatly impinge on the present or demand immediate behavioural change, for many people "peak oil" is an elusive concept that floats about on the periphery of consciousness and intrudes only in the rhetoric of environmentalists, academics and alternative-lifestylers.
The term refers to the point when the maximum rate of global petroleum extraction is reached, after which the rate of production enters terminal decline. Given simultaneous ongoing population increases and a continued drive towards economic growth, petroleum prices will become a constraining influence in the nature of society as it is now, and a determining factor in how it might evolve.
A variety of analyses pinpoint "peak oil" as either having just been reached or predict its imminent arrival. Regardless, a 50% reduction in oil production is expected by 2050, so the society inherited by our grandchildren and great-grandchildren is likely to be markedly different from our own.
Exactly how continues to be a matter of some debate, with those portraying a world shackled to petroleum-related technologies predicting gloomy scenarios lived out in energy-impoverished, "self-sufficient" communities.
Others have greater faith in the creative capacity of humankind to overcome such limits in ways as yet unknown.
How the future is imagined depends to a large extent on the position taken on the continuum between these polar opposites - and the extent of the lag between severe energy supply depletion and the development of accessible, cheap and sustainable alternatives.
Change, however, there will be, and while its precise nature and reach cannot yet be gauged - beyond an uneven future oil supply characterised by periodic price rises and shortages, and long-term gradual decline - it is just as well to prepare for it.
To this end, the Dunedin City Council's Peak Oil Vulnerability Assessment for Dunedin is a welcome initiative.
Peak oil is an issue over which individual communities, this city and region included, will have no control.
Identifying how the council might play its part in managing its economic impacts and potential risks, in particular with respect to energy efficiency, is a responsible approach to local government, regardless of intervening technological innovation.
The document, prepared for the DCC by Dr Susan Krumdieck and EAST Research, hinges on urban form and transport infrastructure and how these can be enhanced to "provide adaptive capacity and resilience in household travel behaviour while supporting local business and enterprise development".
More specifically, the report urges reduced oil consumption of 50% by 2050; a redevelopment of Dunedin's "urban form" to "central city lifestyle development and urban villages, accessed by 100km of safe cycleways and pedestrian zones and served by public transport"; the building of an electric trolley-bus system; and improving the city's average vehicle fleet efficiency to 5 litres per 100km by 2030.
These are ambitious objectives and to begin to make inroads into them an understanding of present habits and likely impacts of rising fuel prices is necessary.
In this respect the report - whether or not its recommendations are agreeable - is helpful.
At the very least it elucidates the patterns of transport in and around Dunedin - for example that 95% of all trips take place in private vehicles.
Such intelligence, along with the suggestion that an electric trolley-bus system would be advantageous to the city, will at least stimulate debate among citizens and planners as to how the city adjusts to an uncertain energy future - as will the notion of a city of "urban villages" providing a range of "shopping, services, cafes, entertainment and weekend markets".
It is a vision in which pedestrian areas and cycle tracks are given greater weight than in the past, and to become a reality requires leadership and a proactive role in urban design and planning by the council.
Ultimately, however, it is the market that will sway people's actions: should the price of petrol continue to rise to prohibitive levels, city residents will modify their behaviour accordingly - whether that be in their choice of inner-city living or preferred modes of transport.
How fast or radically such changes will occur only time will tell.
