Factor Four

The maths of this challenge are daunting. By 2050, if economic growth continues at its recent rate, and population growth reaches the UN medium projection of 9.4 billion, we would need to cut our resource use for each unit of consumption by two thirds. In other words, we would need to increase resource productivity by a factor of three. To reduce environmental burdens to sustainable levels, we would need at least a factor four increase in resource productivity - hence the book's title.

In the long run we will need a lot more than factor four. If population stabilizes at below ten billion, and all the world reaches per capita incomes equal to today's high-income countries, we will need a Factor Ten revolution, as the Factor Ten club founded by Friedrich Schmidt Bleek recommends.

But Factor Four should be our immediate goal, and the beauty of this book is that it shows how feasible that might be on the basis of models that are working right now. Fifty documented examples show dramatic improvements in resource efficiency in energy, materials use and transport - superwindows that let light through but not heat; passive solar buildings in the Rockies that grow bananas in winter with no conventional energy input; refrigerators that use one tenth of the normal energy; systems to quadruple the number of trains that can use the same track, and so on.

Factor Four is not simplistic. It fully recognises the obstacles that have held back the revolution in resource efficiency. Economists have fixed ideas - against the evidence - that saving energy and reducing pollution will always involve net costs. Discriminatory regulations often penalize resource saving over resource wasting. Architects are paid more, the more their building costs. Utility companies earn more, the more energy consumers waste.

So it is incisive in its recommendations. Incentives should be reversed: architects, utility companies and so on should be paid more the more they reduce costs and resource use. The regulatory playing field should be levelled between green approaches and old-style wasteful ways of doing things. Tax systems should be changed to penalize bads, not goods.

Another of the book's virtues is that it shows how the new technologies and approaches can save money, make money, and offer profit opportunities for business folk ready to exploit them. It offers win-win solutions that make life better for people and the planet at the same time.

Factor Four is well-documented, punchy and clearly written, often brilliantly incisive, full of information and original proposals. It is a must for the desks of all policy-makers, businessmen, architects, planners and government ministers throughout the world.

Reviewer: Paul Harrison
Paul Harrison is author of Inside The Third World and The Third Revolution, both Penguin, and a Contributing Editor of People & the Planet.

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