Banner and forest. Photo courtesy Greenpeace International via FlickrLast week, Greenpeace activists blocked rainforest destruction in Indonesia’s Kampar Peninsula by chaining themselves to excavators. Activists then draped a bright red “Obama You Can Stop This” banner over the destruction and called on the world’s leaders to stop deforestation at next month’s climate talks in Copenhagen.

The protest came days before President Obama’s scheduled visit to Asia, and Greenpeace criticized Obama for not taking a more active role: “With just weeks left before December’s critical U.N. climate summit, his administration is actively undermining and stalling the climate change negotiations.”

The “Obama You Can Stop This” banner — and the deforestation around it — highlights some of the biggest challenges facing the Copenhagen crowd. Deforestation accounts for 20 percent of the CO2 emissions that account for climate change.

In Copenhagen, Brazilian President Luiz Lula will offer to reduce deforestation in his country by 80 percent by 2020. Both Lula and other leaders want industrialized countries to do their share by helping developing countries transition to clean energy. But agreeing on who will cut what (in terms of emissions) and who will pay for it has been one of the many hurdles standing in the way of an effective international climate treaty.

Activists can send a form letter to President Obama urging him to “create a $140 billion fund to help poorer nations increase their own renewable energy sources, end deforestation, and adapt to the unavoidable impacts of climate change.”