It is ironic that the third chapter of the Why Geography Matters starts off about global warming. Since the release of Al Gore's movie and The Intergovernmental Panel on Climate Change's (IPCC) report on global climate change last week, the topic has become big news. Despite the fact that the IPCC announced "unequivocal evidence that humans are the driving force behind global warning" (which comes as no surprise), there still are many questions left unanswered, such as would this global warming be occurring without human intervention anyway, but slower; can it be reversed; and what is the timeline. The author's comments regarding the fact that global warming is becoming a moral as well as a scientific arena are appreciated, concerning the amount of time spent on this topic worldwide by politicians, scientists, laypeople-and, as he adds, by the misinformed media.
             This was one of the interesting aspects about Chapter 3 in Why Geography Matters. In this chapter, de Blij reviews the geological time scale that is divided based on rocks and fossil forms. The earth started out with the Hadean (i.e. Hades) Era that included the formation of the Solar System and Earth, outgassing of the first atmosphere and oceans, and the bombardment by leftover planetessimals and debris. The Archean Era followed next, which was an important time when a wide variety of microbial life began to flourish in the primordial oceans and the continental shields developed from volcanic activity.
             The next Proterozoic Era saw the atmosphere for the first time have oxygen and some early life forms began. Early in the 300 million year history of the following Paleozoic Era, atmospheric oxygen reached its present levels, establishing the ozone shield that screens out ultraviolet radiation and permits complex life in the shallows and on land. With the extinction of the dinosaurs and the end of the next Mesozoic Era, the mammals swiftly inher...