Answer:
carbon dioxide
Explanation:
The Environmental Kuznets Curve (EKC) was developed in 1995 by Grossman and Krueger. It is based on the hypothesis that as per capita income grows, negative environmental impacts increase, they reach a maximum, and then start to decline. That is why they shaped it as an inverted U.
The only pollutant that keeps rising is carbon dioxide since it is a direct byproduct of many industries, transportation systems, and animals (especially cows).
