As Shell makes preparations to send offshore drilling rigs into the Beaufort and Chukchi Seas north of Alaska, it's important to walk through the history of energy exploration in the Arctic.
Wind, solar, hydro, and geothermal seem mostly benign -- in part because they are still a small part of the energy equation. But when green gets big, it can be controversial.
This month the US approved four wells for drilling by Shell Oil in the Arctic Ocean off Alaska, an energy frontier. But Shell's plan to recover after an oil spill is completely inadequate, given the region's remoteness and weather.
So far, there are no bombshells in the thousands of Sarah Palin emails released this week. But they reveal a fuller, more nuanced picture of one of the most powerful and controversial women in US politics today.
Earth Day was launched 41 years ago today by a US senator who was alarmed by the 1969 Santa Barbara oil spill and inspired by the student antiwar movement.