Assessing IPAT using production- and consumption-based measures of I

Objective. Researchers have frequently used the formula I = PAT (IPAT) to illustrate how population (P), affluence (A), and technology (T) have acted as the primary forces behind environmental impacts (I). The purpose of this study is to illustrate how the methods used to calculate a specific variable or variables used to measure I may have an impact on the resultant strength of the IPAT formula. Methods. We compared production-based and consumption-based estimates of total greenhouse gas (GHG) emissions data in 1990 for a twelve-county sample in northwestern North Carolina to Various measures of population and affluence by using correlation and bivariate mapping. Results. Consumption-based GHG emissions correlate strongly with most measures of population and affluence. Production-based relationships are weaker because they are influenced by the geographic placement of facilities (e.g., fossil fuel-based power plants) that can account for a large proportion of GHG emissions within an individual county. Conclusions. Results from this study suggest that how the I in IPAT is defined can have an impact on the strength of the formulation. Additionally, this work shows that IPAT, which is most often applied at the global scale, can be successfully used to examine the driving forces behind environmental impacts at the local scale.