Smith, a UCLA geography professor, explores megatrends through computer model projections to describe "with reasonable scientific credibility, what our world might look like in forty years' time, should things continue as they are now." Laying out "ground rules" for himself--including an assumption of incremental advances rather than big technology breakthroughs and no accounting for "hidden genies" such as a decades-long depression or meteorite impact--he identifies four global forces likely to determine our future: human population growth and migration; growing demand for control over such natural resource "services" as photosynthesis and bee pollination; globalization; and climate change. He sees the "New North" as "something like America in 1803, just after the Louisiana Purchase... harsh, dangerous, and ecologically fragile." Aside from his observations of "a profound return of autonomy and dignity to many aboriginal people" through increasing political power and integration into the global economy, Smith's predictions, limited by his conservative rules, are far from earthshaking, and suspending his rules for a chapter, he admits that "the physics of sliding glaciers and ice sheet collapses" as well as melting permafrost methane release are beyond current models, and that even globalization could reverse, with "political genies even harder to anticipate than permafrost ones."