CANCUN, Mexico -- Clumps of black, straw-like seaweed dot the beach at Boca Paila on the Yucatan Peninsula. Gnats swarm the deposits. Clumps of grass add to the difficulty of sunbathing in comfort.

Marie Claire Paiz loves it.

"At one point, Cancun was like this," Paiz, a Guatemalan biologist who directs the Nature Conservancy's Southern Mexico program said, her arms spread wide.

Where tourists see nuisance, Paiz and local scientists see unspoiled nature doing its job. The seaweed and grass -- and absence of mega-resorts built atop the dunes -- allow sand to accumulate naturally. That, in turn, helps protect the Mesoamerican Barrier Reef, which stretches past four countries from the northern tip of Mexico's Yucatan Peninsula to the Bay Islands of Honduras.

But Boca Paila, part of the Sian Ka'an Biosphere Reserve about three hours south of Cancun that the Nature Conservancy helps manage, is an exception. Far more common, scientists here say, is the runaway development of the corridor between Cancun and Tulum, where in little over a decade, fishing villages have been transformed into traffic-clogged resorts, 18-hole golf courses and new housing developments.

The result already has been devastating to the coral reefs, scientists say. What they don't know is precisely what impact climate change will have on top of rampant development. But they have a pretty good guess: the utter destruction of the Mesoamerican fishing supply, and the eventual loss of Mexico's greatest tourist draw as sea levels rise.

"If we reach an agreement similar to the one that was proposed for Copenhagen, two degrees, that would be the end of the coral reef," said Roberto Iglesias Prieto, head of the Unidad Academia de Sistemas Arreficiales in Puerto Morelo, where the main work these days is studying the impact of climate change on coral reefs.

Cancun's goal may not be enough
The goal that world leaders came to at last year's climate summit in Copenhagen, Denmark -- not to let the world exceed a global average temperature rise of 2 degrees Celsius above pre-industrial levels -- doesn't go far enough, Prieto said. A world in which atmospheric CO2 rises to 450 parts per million will look "very bad" for the corals and those who depend upon them, Prieto said.

"It's the basis for the tourist industry. It's the basis for food security, not only for people in Mesoamerica but also for 200 million people for whom the reef represents a major source of protein and sustenance. And on top of that, this is one of the most beautiful ecosystems on the planet. It's spectacular," he said. "If we lose corals, we lose services."

Paul Sanchez-Navarro, director of the nearby Akumal Ecological Center, put it in market terms.

"What's for sale here is nature," he said. "Nature is the product, and very little is being done to protect that product. If we were dairy farmers, we'd be the worst dairy farmers in the world."

As United Nations climate change treaty talks in Cancun enter their second week, Mexico is playing a unique roll. Both a victim of greenhouse gas emissions and a major producer of them, Mexico has done more than almost any country to throw off the label of "developed" and "developing" countries that have for years pigeon-holed nations.

The second-largest emitter of greenhouse gases in Latin America, Mexico accounts for about 1.5 percent of the world's emissions of greenhouse gases, according to the United Nations.

And while under the current 1997 Kyoto Protocol climate treaty, Mexico is not bound to make any move to reduce emissions without assistance from more industrialized nations, it made a splash two years ago as the first country to set itself unilateral emission targets.

"They were one of the first countries to explicitly recognize a framework, which is that they will take action while at the same time developed countries will take action. They were the first ones to articulate that vision," said Jake Schmidt, international policy director for the Natural Resources Defense Council.

Taking an 'aggressive' stand
"They're probably one of the most aggressive countries in terms of climate change," agreed Ned Helme, director of the Center for Clean Air Policy in Washington, D.C.

He described Mexico as a "unique developing country" that is not part of the Group of 77 negotiating block. But despite its membership in the Organisation for Economic Co-operation and Development, which covers 33 countries that are all committed to democracy and a market economy, it also is not quite considered a developed country either.

Mexico has pledged to reduce its emissions 30 percent below its business-as-usual rates in the next decade. Helme said achieving that would be the equivalent of almost as much reduction as the U.S. target, in terms of relative percentage reductions. Meanwhile, Mexico's mid-century goal of reducing greenhouse gases 50 percent below business as usual is "as big as any annex one country," Helme said.

"They're very aggressive in terms of their aspirational goals, and they've coupled it with a real effort to identify opportunities on the ground," he said. "They're really doing the work."

It's not without major challenges. Chief among them: Mexico's two major state-owned enterprises -- its Comision Federal de Electricidad (CFE) electricity sector and Pemex, the state oil monopoly -- are also the country's largest source of emissions.

"The dynamics of each of those is a big barrier for moving forward on policy," Schmidt said, noting that Pemex is a large source of the government's revenue, so any investments the company makes to upgrade its refineries compete against social needs.

A drive to use waste heat from refining as electricity generation, for example, has been stalled by the need for major early investments for which Pemex has been unable to get budget support, he said.

Developing wind, solar, geothermal ... and tourism
Meanwhile, a constitutional requirement restricting independent power producers from selling energy to the grid has caused some hiccups for the country's renewable energy potential -- but experts in the United States and Mexico said the country is starting to find solutions to the policy barriers and has made major investments in wind, solar, geothermal and other renewable energy projects. On transportation, Mexico also is close to passing a vehicle efficiency standard which Schmidt said is expected to include key controls for local air pollution.

Closer to Cancun much of the work being done is on deforestation, which Paiz said has decreased over the past eight years. But with 30 percent of the country's forest loss taking place in the Yucatan region, she said the country still needs better controls.

This week Mexican President Felipe Calderon will announce Mexico's vision for avoiding deforestation, and today three governors will make a joint declaration on climate change.

But local scientists who work close to the sprawling resorts of Cancun say there needs to be more education at a local level.

Development is only expected to increase. Sanchez-Navarro -- who works with local hotels to encourage them to improve wastewater treatment plants and other measures -- said it's still a struggle to convince local authorities that rising sea levels and deforestation pose a threat to the local economy. He noted that between Akumal and Tulum about 8,000 hectares of deforestation is planned, carrying an impact that has not even been calculated.

Meanwhile, the more development that occurs means the more waste that will go into the groundwater, making it difficult for corals to calcify and slowly killing off the coral reefs so many come here to see.

Many are concentrating on what they can control -- local watershed management that, he said, might be able to protect the reefs until nations take global action on climate change.

"The question is, can corals adapt as fast as climate change?" Sanchez-Navarro said. Scientists don't know the answer yet. They say they are working against the clock.

"Even if today we have an agreement and stop producing CO2, we are already committed to a 1.5 degree rise [over pre-industrial temperatures]. That is bad for the reefs, but they will rebuild," Prieto said.

Cleaning the local waters could give the reefs another 70 healthy years, Prieto said, adding, "You can buy time, and if you buy enough time we will probably reach an agreement."

Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC., 202-628-6500