Abstract
The aim of the present study is to investigate the relationship between both city size and welfare or prosperity on the one hand, and environmental-climatological outcomes on the other hand. This will be done by examining this intriguing relationship for a sample of 40 large cities in our world (with different size categories and located in countries with different welfare levels). Based on detailed statistical data on a multiplicity of relevant characteristics of these cities (stemming from the GPCI metropolitan data base of the Mori Memorial Foundation (2016)), we have used a super-efficient Data Envelopment Analysis (SE- DEA) to analyse the relative economic-environmental efficiency outcomes of distinct classes of global cities, so as to test the above mentioned double proposition, coined here double delinking or the double Kuznets curve phenomenon.