https://en.wikipedia.org/wiki/I_%3D_PAT

I = (PAT) is the mathematical notation of a formula put forward to describe the impact of human activity on the environment.

    I = P × A × T

The expression equates human impact on the environment to a function of three factors: population (P), affluence (A) and technology (T).

The variable A in the I=PAT equation stands for affluence. It represents the average consumption of each person in the population