On my way back from a carbon burning orgy weekend--seven hours of driving to carbon powered ski lifts, wearing petroleum-based clothing and swimming in a heated outdoor pool--I tuned into a National Geographic radio program on Angkor Wat. After some praise of the brilliance of the temple engineers, the Australian archeologist turned the discussion to, naturally, global warming. It appears that the decline of the Khmer kingdom in the 13th century was likely tied to the clear-cutting of the forests around the temples to build rice paddies, which led to a climate change--which, as we know, destroys empires. The parallels with the today's climate change are disturbing: these Khmer temple builders had put all their faith in a technology that led to their downfall, much like the modern western world's dependence on carbon-based technologies.
So the SUV of the 12th century Cambodia was the rice paddy. It all makes sense.