Population growth and global CO₂ emissions: A secular perspective

Considerable scientific effort has been applied to the question of whether worldwide fossil fuel combustion and the resultant emission of CO₂ (as well as emissions of other greenhouse gases) will cause a discernible enhancement of the greenhouse effect in the next century. A more precise understanding of the contribution of human activity to potential global warming (vis-à-vis natural climatic variability) is of critical policy interest. Surprisingly little research has been devoted to establishing the underlying statistical relationship between human activities and CO₂ emissions. In this paper, we explore the nature of the relationship between global population growth and CO₂ emissions by employing the test of causality developed by Granger on annual data for 1880-1989, as well as more comprehensive error correction and cointegration models. The results suggest a lack of a long-term equilibrium relationship, but imply a short-term dynamic relationship from CO₂ to population growth.