Air pollution and economic development, a tested an Environmental Kuznets Curve Hypothesis for some countries, with a special mentioned to Iraq for the period (1990-2020)

The research aims to identify the hypothesis of the environmental Kuznets curve, to clarify the relationship between economic development and air pollution, its path and reversal point in the United States of America, India, and China with special reference to Iraq during 31 years for each country in the research sample. The descriptive-analytical approach supported by statistical data, figures, graphs, and mathematical equations was used to prove the research hypothesis. The large amount of carbon dioxide emissions by some countries is due to the large industrial activity that has exacerbated the threat of environmental damage through: (global warming, changes in the biological system, and finally climate change). This leads us to ask the following question: Have these countries really started the process of combating air pollution, or have they put their interest in achieving economic growth over environmental damage? The researchers came to several conclusions, the most important of which are: The United States of America has already entered the stage of reducing air pollution after a certain level of average real income ($32,532.6), while Iraq has achieved a similar shape to the Kuznets curve at an inversion point of real income average ($5773), while India and China have achieved a clear increase in economic growth at the expense of an increase in air pollution.