Trees loom large over the proceedings in Copenhagen. Here in this sprawling, climate-controlled complex of low-slung metallic hangars where the negotiations are unfolding, the fate of the earth’s forests may rest with decisions reached by the end of the week. The question is how to pay the estimated $15 to $25 billion it will cost over the next five years to start reducing deforestation by 50 percent by 2020 and eliminate it by 2030. These are the goals being set for any serious reductions on greenhouse gas emissions.

The first signal of where these forest negotiations are headed came Saturday afternoon, when the Ecosystems Climate Alliance, a group representing a coalition of international and U.S. NGOs, claimed it had obtained a draft of what such a deal would look like. Called REDD, which stands for Reduced Emissions from Degradation and Deforestation, the agreement set no clear guidelines on whether public or private money would pay to protect forests — a critical area of debate.

The draft also downplayed another sensitive issue — getting Prior Informed Consent from the indigenous people living in the forests. Environmental groups across the spectrum, including Global Witness and the Rainforest Action Network are particularly wary of forests being subjected to the forces of a carbon market.

Even the Nature Conservancy, which has been pro-market in saving forests, is demanding that provisions for people living in them be a central part of any agreement.

If and when private companies will be able to purchase forestlands to preserve them is at the heart of these negotiations. The United States is aligned with tropical nations like Indonesia, the Congo and Papua New Guinea, arguing that the best way to preserve forests is by permitting companies to protect them through offset funds.

Meanwhile, the European Union is advocating for a multistage approach, which would begin with public support to prepare countries over the next several years to manage their forests sustainably before subjecting them to the market. Both sides have yet to agree on how much money will be committed, and from where.

Rosalind Reeves, a forest campaign manager for the environmental and human rights group Global Witness, working in Kenya, is concerned that linking forest preservation directly to the carbon market could lead to a boom in government corruption, especially in countries that have large areas of tropical forest in tact — like the Congo and Papua New Guinea.

“A lot of people see [the REDD agreement] as a big opportunity to save the forests,” Reeves said, “but there are lots of risks attached.” If you get a deal that “doesn’t protect the natural forests and the rights of the people who live in that forest, and doesn’t promote strong governance or include effective monitoring, then you’ve got problems,” she said.

Reeves has gone from tracking the illegal wildlife trade to the illegal logging trade and is now trying to ensure that the market solution for preserving forests favored by the United States does not create an entirely new business in carbon crimes. Any agreement is in peril without the ability to properly enforce it.

The Lusaka Agreement Task Force is one of the enforcement operations talking to delegates. The group was created under a joint agreement between several African nations and draws from enforcement agencies across West Africa. The group is helping advise on REDD guidelines so that accounting for fraud and other potential abuses are not overlooked.

In many parts of the world, land titles are unclear; and the rules governing how to account for forestlands, even tax them, have yet to be written.

“You have unclear rules, a whole economy being formed — it’s ripe for criminals,” said Davyth Stewart, a former organized crime investigator in Australia’s national police force. He’s now a lawyer with Global Witness, and focusing on this new market for forests.

Over the next year, FRONTLINE/World and CIR will report on key issues of climate change in a joint project—Carbon Watch—focusing on the multi-billion-dollar carbon trading market. We’ll look at which proposals to reduce emissions by 2020 really add up; at the hidden interests behind these solutions; and the new industry players. This week, our reporters blog from the Copenhagen climate change summit.

Mark Schapiro specializes in international and environmental stories. His award-winning work appears in all media: in publications such as Harpers, The Atlantic, Mother Jones and Yale 360; on television, including PBS FRONTLINE/World and KQED; on public radio including Marketplace; and on the web. He is currently writing a book for Wiley & Co. investigating the backstory to our carbon footprints. His previous book, "EXPOSED: The Toxic Chemistry of Everyday Products and What’s at Stake for American Power," reveals the health and economic implications of the tightening of environmental standards by the European Union.