We live in a world of ﬁnite natural resources and sources of energy. Unfortunately, we are currently using these natural resources at a rate that cannot be sustained indeﬁnitely. Moreover, the energy that we expend in exploiting these resources, and the ways in which we use and consume them, produces pollution and a degradation of the environment. In particular, the so-called greenhouse gas emissions resulting from our use of resources (mainly carbon dioxide, methane, and nitrous oxide), contribute signiﬁcantly to global climate change. Thus, if we wish to maintain our current standard of living, and to bring the developing world up to these same standards, we must pay much more attention to the way in which we deal with our natural environment. This leads inevitably to the concept of sustainable development, which is most commonly deﬁned as:
Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.