Faster, Sooner, and More Simultaneously: How Recent Road and Air Transportation CO₂ Emission Trends in Developing Countries Differ From Historic Trends in the United States

This article explores historic carbon dioxide (CO 2 ) emission trends from road and air transportation of the United States and 26 developing and industrializing nations. It is argued that environmental trends in the newest industrializing countries do not follow the more sequential and long-term shifts experienced by the United States. The empirical analysis demonstrates that all rapidly developing countries analyzed exhibit comparable transportation CO 2 emissions per capita levels at lower levels of income per capita, or sooner, than the United States. For some developing countries (the most rapidly growing), these emissions also grow faster over time. Last, there is clear evidence that emissions from road and air sources are occurring more simultaneously compared to the United States. This pattern of changes is in contrast with the common interpretation of environmental Kuznets curves, which suggest that countries follow similar patterns of environmental impacts over time as they develop economically.