The Three Horses of Sustainability—Population, Affluence and Technology

The IPAT equation provides a simple but powerful model for understanding sustainability, particularly from the challenge posed by the Anthropocene—how to reduce personal or societal impact. Impact is calculated by multiplying population, affluence and technology, and a ‘reduction coefficient’ e is used to explore targeted reductions in impact of different entities to cap total (summed) impact. The model offers two solutions. First, that all three factors are essential in determining total impact; a focus on just one or two is not justifiable without credibly addressing the other(s). Second, by presenting reduction of impact as a proportion of current activity, the solution becomes accessible to an individual actor (e.g., an individual, family, organization, or country). Application of the model is illustrated based on household weekly food consumption from cultures around the world. The model helps unify a) disparate perspectives on population, affluence and technology, which currently oppose one another from a basis of belief or dogma, and b) different sectors (e.g., food production, energy, climate impacts and others), as well as actors, so they can jointly identify strategies to resolve their contributions to approaching larger scale sustainability.

Population growth, energy use, and environmental impact: Comparing the Canadian and Swedish records on CO2 emissions

There are many similarities between Canada and Sweden, as both are relatively affluent northern nations with diverse modern economies. Both have witnessed demographic growth and climbing affluence, with predominantly export-oriented economies. Yet in terms of their respective records on greenhouse gas emissions, there is a stark contrast between the two. Sweden is often considered a world leader in reducing emissions, whereas Canada has been widely criticized for its failure to meet international commitments. The current paper attempts to delineate some of the factors responsible for the observed differences between the two countries. It examines trends in environmental impact (CO2 levels) by applying a modified and updated version of Ehrlich’s IPAT equation. The crux of the matter in comparing the two countries is Canada’s substantial population growth and heavy demand for energy (29th among 30 countries in the OECD on our measure of energy intensity) whereas Sweden has managed to move away from fossil fuels in driving its economic activity.