If generalizations cannot be tested, then not a scientific statement. Environmental science the study of how the natural world works, how our environment affects us, and how we affect our environment. Can never provide absolute truth, but can provide increasingly better approximations. Change in knowledge is inevitable as new information is gathered. 7 billion as of oct 2012: within the past 200 years we have gone from 1 billion to 7 billion people on earth exponential growth. Nearly 1 in 4 live in extreme poverty. In our developed economies there seems to be a correlation between consumption and economic growth. Highly developed countries: ~ 20% of world"s population example, canada, Poor countries make up 80: moderately developed example mexico, turkey, less developed (ldcs) example bangladesh, ethiopia. Developing countries: rapid population growth overwhelming, natural resource depletion to feed the growing population. Developed countries: slower population growth, higher rate of consumption, natural resources required to supply desires and needs.