Jeffrey Brown:

The people who carved them arrived here from Pacific Islands to the west beginning as early as 940 A.D. The Rapa Nui people survived and thrived. The population may have reached 15,000 to 20,000.

But something, or things, happened. Just what is still much debated. An overuse of resources, including cutting down forests. The importation of seed-eating rats on the Polynesian canoes. Civil wars among the people here that left the Moai toppled.

All the statues we see standing on ceremonial sites today have been restored since the 1950s, this one by the famed explorer Thor Heyerdahl.

Finally, the coming of Europeans, first on Easter Day in 1722, thus the island's name. Easter Island became a symbol of what humans can achieve and then destroy. And it is once again today. The new threat, climate change.

Laura Gallardo directs the Center for Climate and Resilience Research at the University of Chile.