An inverted-U relationship between GDP per capita and three urban transport-related emissions is tested (using data from 84 cities). Per capita urban transport-related emissions of CO, VHC, and NOx increase and then decline at observed income levels—a result driven by a similar inverted-U...

Two important, increasing trends for those concerned about climate change to consider are urbanization/the importance of cities and energy used in transport—particularly energy used to achieve personal mobility. While national urbanization levels are not a good indicator of urban transport...