The advent of EKC raises many questions: What have we learnt about the statistical relationships between various measures of environmental quality and income? Do all aspects of environmental quality deteriorate or improve systematically with economic development? At what point on the Y-axis does the turn of the EKC arise? What is the threshold income level at which it falls? In doing so does it go all the way to the X-axis (Figure 3.1)? What is the proportion of the area under the curve before the threshold? Most of all our concern is about a prime question. Does a global EKC exist?