In a report scheduled for release next month, the U.N. Intergovernmental Panel on Climate Change is expected to endorse emissions trading and protecting forests and planting new ones as effective strategies to curb global warming. A final draft of the report says that the cost to industrialized countries for fighting global warming could be cut in half if they were allowed to buy and sell credits earned by the countries that make the deepest reductions in greenhouse gases. It also concludes that countries could use forests to absorb 10 to 20 percent of the carbon dioxide that is expected to be released by car tailpipes and industrial smokestacks over the next 50 years. The U.S. strongly favors using forests and emissions trading as methods to combat climate change, while the European Union thinks the majority of emissions cuts should be made at home at the source of the pollution.