Energy intensity, CO2 emissions and the environmental Kuznets curve. The Spanish case

This article analyses the role of energy intensity and the relationship between CO2 emissions and primary energy in order to explain the evolution of CO2 emissions by unit of real GDP. It also distinguishes two different meanings of CO2 emissions Kuznets curve hypothesis: the weak and the strong sense. It considers the case of Spain in the period 1972–1997 as an example in which there is not any evidence supporting this hypothesis in either sense.