Gradual disintegration, not sudden collapse?: "Like modern industrial society, the Maya built their civilization on a nonrenewable resource base. In their case it was the fertility of fragile tropical soils, which couldn't support intensive corn farming forever. On that shaky foundation they built an extraordinary civilization with fine art, architecture, astronomy, mathematics, and a calendar more accurate than the one we use today. None of that counted when the crops began to fail. Mayan civilization disintegrated, cities were abandoned to the jungle, and the population of the Mayan heartland dropped by 90%.

"The parallels go deeper, for the Maya had other options. They could have switched from corn to more sustainable crops such as ramon nuts, or borrowed intensive wetland farming methods from their neighbors to the north. Neither of these happened, because corn farming was central to Maya political ideology. The power of the ahauob or 'divine lords' who ruled Maya city-states depended on control of the corn crop, so switching crops or farming systems was unthinkable. Instead, Maya elites responded to crisis by launching wars to seize fields and corn from other city-states, making their decline and fall far more brutal than it had to be.

"Even so, the Maya decline wasn't a fast process. Maya cities weren't abandoned overnight, as archeologists of two generations ago mistakenly thought, but went under in a 'rolling collapse' spread across a century and a half from 750 to 900. Outside the Maya heartland, the process took even longer. Chichen Itza far to the north still flourished long after cities such as Tikal and Bonampak were overgrown ruins, and Mayan city-states on a small scale survived in corners of the Yucatan right up to the Spanish conquest."

Gradual disintegration, not sudden collapse?: "Like modern industrial society, the Maya built their civilization on a nonrenewable resource base. In their case it was the fertility of fragile tropical soils, which couldn't support intensive corn farming forever. On that shaky foundation they built an extraordinary civilization with fine art, architecture, astronomy, mathematics, and a calendar more accurate than the one we use today. None of that counted when the crops began to fail. Mayan civilization disintegrated, cities were abandoned to the jungle, and the population of the Mayan heartland dropped by 90%.

"The parallels go deeper, for the Maya had other options. They could have switched from corn to more sustainable crops such as ramon nuts, or borrowed intensive wetland farming methods from their neighbors to the north. Neither of these happened, because corn farming was central to Maya political ideology. The power of the ahauob or 'divine lords' who ruled Maya city-states depended on control of the corn crop, so switching crops or farming systems was unthinkable. Instead, Maya elites responded to crisis by launching wars to seize fields and corn from other city-states, making their decline and fall far more brutal than it had to be.

"Even so, the Maya decline wasn't a fast process. Maya cities weren't abandoned overnight, as archeologists of two generations ago mistakenly thought, but went under in a 'rolling collapse' spread across a century and a half from 750 to 900. Outside the Maya heartland, the process took even longer. Chichen Itza far to the north still flourished long after cities such as Tikal and Bonampak were overgrown ruins, and Mayan city-states on a small scale survived in corners of the Yucatan right up to the Spanish conquest."