International climate negotiators left Poland last week with a roadmap for completing work on a global-warming treaty in 2009 — a small yet critical step in the face of the global economic meltdown. But delegates left the basic questions about how to structure the deforestation deal for next year. Frances Seymour who heads the Center for International Forestry Research in Bogor Barat, Indonesia, says the architecture will have to be flexible : a market-based approach might breed corruption in countries with poor governance and weak institutions, but could do well where the problem is one of resources. « This is the biggest thing that has happened in forest conservation in 15 years, » she says. « But it also has the potential to crash and burn if we get it wrong. »