Revisiting Jevons’ Paradox with System Dynamics: Systemic Causes and Potential Cures

This article examines the dynamic relationship between the consumption of goods and services, technological efficiency, and associated resource use, as described by the theory of Jevons' Paradox (JP). A theory is presented about what causes JP, in which resource efficiency savings are eventually overtaken by increases in consumption to produce a net increase in resource use and therefore environmental impacts. An application of the theory was carried out using system dynamics, modeling carbon dioxide equivalent (CO2-eq) emissions from private road transport in the UK between 1970 and 2010. The model results indicate the approximate impact of JP within the historical period: a rise in travel consumption of approximately one half and a rise in CO2-eq emissions of approximately one third. The model was used to estimate whether the European Union (EU) goal of a 40% drop in CO2-eq emissions by 2030 is achievable in the road transport sector, by adding interventions, and the results indicate that higher increases in fleet efficiency than are currently forecast, costlier travel, and a reduction in travel consumption would all be required. The theory and model presented in this article highlight the need to implement a system of interventions that can influence the strength and direction of each of the feedback loops within the system being intervened with, if CO2-eq emissions are to be more reliably reduced than they are at present. Further, because the system is constantly evolving, intervening with it requires a responsive, holistic approach, while maintaining focus on a long-term goal.