Environmental Kuznets curve

1. a semi-circle curve suggesting increase in per-capita income increases the pollution
2. a U-shaped curve suggesting the level of development and carbon emission
3. suggest a U-shaped relationship between the carbon emission and Ozone layer depletion
4. suggest a bell-shaped relationship between the concentration of certain pollution emission and per-capita real GDP

suggest a bell-shaped relationship between the concentration of certain pollution emission and per-capita real GDP