Thomas Friedman makes his argument throughout Hot, Flat, and Crowded explicitly and repeatedly: climate change is real and imminent, the world economy is flattening due to globalization, and population growth will cause the demand for resources to rise in intensity. Because Friedman's argument is so explicit, so are many of his themes. However, other themes run through these explicit arguments.
Friedman drives home the interconnectedness of existence many times and in many ways. For some authors, this might be a philosophical point, and a fairly abstract one. Friedman argues, however, that in the contemporary world this interconnectedness is very concrete, very pressing, and absolutely essential to acknowledge. This interconnectedness applies in the conceptual, economic, biological, and all other realms. When humanity lived in small, isolated groups of hunter-gatherers or sustenance farmers, one group's ideas or pollution, no matter how toxic, couldn't really harm another.
Those days are gone. Because the planet has exceeded its carrying capacity, at least using our current technologies, one group's poisons are continually spilling over onto another's space. When one group cuts down a rain forest for money, it kills rare species that would benefit everyone and diminishes the biosphere's ability to deal with the excess carbon dioxide we're pumping into the atmosphere. All technological activity everywhere contributes to global warming. This produces climate change, not just locally, but everywhere.
Many of the actions Friedman describes in his book are thought of as local or at best national: people think about what they want to do, or what their nation (whatever that may be) should do. While local action is absolutely crucial, it is no longer enough. Instead, we must have global action if we have any hope of dealing with the problems we're facing, and this action must likely be coordinated...
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