Maya May Have Caused Civilization-Ending Climate Change

Anne Minard
for National Geographic News
February 29, 2008
Self-induced drought and climate change may have caused the destruction of the Maya civilization, say scientists working with new satellite technology that monitors Central America's environment.

Researchers from the Marshall Space Flight Center in Huntsville, Alabama, launched the satellite program, known as SERVIR, in early 2005 to help combat wildfires, improve land use, and assist with natural disaster responses.

The researchers occasionally refer to the project as environmental diplomacy.

But the program also found traces of the Maya's hidden, possibly disastrous agricultural past—and is now using those lessons to help ensure that today's civilizations fare better in the face of modern-day climate change.

SERVIR stands to warn leaders in Central and South America where climate change might deliver the hardest hits to their ecosystems and biodiversity, say developers Tom Sever and Daniel Irwin.

If the governments heed the warnings, the data may truly save lives, the experts add.

Secret Farms

More than a hundred reasons have been proposed for the downfall of the Maya, among them hurricanes, overpopulation, disease, warfare, and peasant revolt. (Read "Maya Rise and Fall" in National Geographic magazine (August 2007).

But Sever, NASA's only archaeologist, adds to evidence for another explanation.

"Our recent research shows that another factor may have been climate change," he said during a meeting of the American Association of the Advancement of Science in Boston, Massachusetts, earlier this month.

One conventional theory has it that the Maya relied on slash-and-burn agriculture. But Sever and his colleagues say such methods couldn't have sustained a population that reached 60,000 at its peak.

The researchers think the Maya also exploited seasonal wetlands called bajos, which make up more than 40 percent of the Petén landscape that the ancient empire called home.

In most cases, Maya cities encircled the bajos, so archaeologists thought the culture made no use of them. But groundbreaking satellite images show that the bajos harbor ancient drainage canals and long-overgrown fields.

That ingenious method of agriculture may have backfired.

The data suggest that the combination of slash-and-burn agriculture and conversion of the wetlands induced local drought and turned up the thermostat. (Related: "Climate Change Killed off Maya Civilization, Study Says" [March 13, 2003].)

And that could have fueled many of the suspected factors that led to the Maya decline—even seemingly unrelated issues like disease and war.

Proven Success

The SERVIR researchers are now taking their theories to the people, showing tabletop-size satellite images to villagers and national leaders that reveal deforestation in some cases and still-lush landscapes in others.

In one instance the Guatemalan congress was inspired to create the Maya Biosphere Reserve, Central America's largest protected area, after viewing satellite imagery and seeing striking differences between their forests and those that had been clear-cut to the north.

SERVIR, which is being supported in part by USAID and the World Bank, has also proved its worth in other ways since the program's headquarters was opened in Panama at the Water Center for the Humid Tropics of Latin America and the Caribbean (CATHALAC).

In 2006 Panamanian President Martin Torrijos used the SERVIR office as his command post during widespread flooding—and when SERVIR technology forewarned of landslides, he paid attention.

CATHALAC senior scientist Emil Cherrington has never deleted the text message the government sent out that day—a red alert about the landslides SERVIR said were imminent. Cherrington called the cooperation "inspiring."

"It was a pretty neat example of the decision makers acting on information when it was provided," he said.

Last year Central American governments also consulted SERVIR for predictions about Hurricanes Dean and Felix and Tropical Storm Noel.

Heavy Burden

Despite these local efforts in environmental stewardship, however, Latin American countries are facing a heavy burden from worldwide climate change.

Already, rains don't come as predictably to the Petén region, NASA archaeologist Sever said.

Local residents say their chicle trees are yielding fewer harvests, and clouds are forming higher and later in the day, sometimes not sending down rain at all, he pointed out.

Through SERVIR, Sever and his team are monitoring soil and plant responses to the changing conditions. They're also making maps for the ministries of environment and agriculture in several countries.

And CATHALAC's Cherrington, who is from Belize, is using the information to predict how climate change will alter his home country into the future.

"Belize is really a country where biodiversity conservation is possible," he said, speaking at the AAAS meeting.

Cherrington said precipitation will be disrupted most in the mountains, and temperatures will increase the most on the coasts. SERVIR data is predicting that some bird and mammal species will be lost, but amphibians will be the hardest hit.

If satellite precipitation forecasts can be passed to farmers, they'll be able to make decisions about crops based on how much water they'll require, he added.

The SERVIR scientists also hope to expand the space-based technology into other realms. They're looking to develop the kind of air quality index for Central America that is standard on United States weather reports.

And industry has already suggested applications that the SERVIR scientists didn't originally have in mind. A Panamanian company seeking to build solar panels asked recently if SERVIR could show them where to find the best sun exposure.

"It's kind of astounding," Cherrington said, "how space-based information can lead to making better decisions."

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