Peter Head: The world's resources are running low; we need to economise

TWO weeks ago, I was asked by the Royal Town Planning Institute to deliver the annual Sir Patrick Geddes Memorial Lecture in Edinburgh, which seemed to me to be a unique opportunity to explore vital changes we ignore at our peril with some of Scotland's leading town planners.

Nearly a century ahead of his time, Sir Patrick was undoubtedly an eco-missionary, who believed in evolution and spirituality ethics. He was actually a biologist, who had taken it upon himself to reintroduce nature into urban planning.

So the timing of RTPI's invitation was excellent, especially in view of some disappointing outcomes after the Copenhagen climate change summit.

The amount of land available to support our life is shrinking as the population grows. In 1900, there was 7.91 hectares of land per capita. That has shrunk to 1.8 hectares a person and will decline to less than 1.5 hectares per capita at best in 2050. In Europe our lifestyles use six hectares per person in resources.

The way we protect and use natural capital is critically important. We need to manage the global economy based on GDP so that it reaches optimal scale, with efficiency driven by the market and greater use of renewable resources and closed loop resource systems.

There is also disturbing evidence that low and middle income countries are massively more affected by climate change. For example, 20 years ago approximately 1,800-million low and middle income people in the world were already affected in some way by climate change, compared with almost none among high income people. By the 2000s, this has grown to nearly 4,000-million low and middle income people affected compared with 100 million high income earners.

But it's not all bad news. Low and middle income people are now looking for a transition from agricultural to an ecological age, with a new paradigm of urban and rural development with integrated urban-rural resource flows – viz the new eco-cities in China.

Energy consumption has to be moderated in high-income countries – the United States consumes at least five times as much energy per person as consumers in large cities in China. US transport densities are also unsustainable in the US: the average citizen in Houston, Texas, uses seven times as much private transport energy as someone in Hong Kong, where urban density is ten times greater.

The world's oil reserve supply is unlikely to be able to keep up with increasing demand in the near future and so renewable energy resources will become critical to future economic success of regions and cities and these must be balanced in terms of local, national and international energy supply networks.

That is only the very briefest of snapshots of the essential transition of mankind to an ecological age, which planners must become aware of, so I should leave readers with nature champion Janine Benyus's Ten Principles of Biomimicry.

These are: diversify and co-operate; use waste as a resource; gather and use energy efficiently; optimise not maximise; use materials sparingly; clean up, not pollute; do not draw down resources; remain in biospeheric balance; run on information; and, finally, use local resources.

These are all principles advocated by Sir Patrick Geddes and his work can be a real inspiration for the transition to the ecological age, a sustainable economic future, in Scotland.

• Peter Head is sustainable economic development director of the engineering firm Arup.