Climate change 2001 : mitigation; contribution of Working Group III to the Third Assessment Report of the Intergovernmental Panel on Climate Change Setting the stage : climate change and sustainable development Greenhouse gas emission mitigation scenarios and implications Technological and economic potential of greenhouse gas emissions reduction Technological and economic potential of options to enhance maintain and manage biological carbon reservoirs and geo engineering Barriers opportunities and market potential of technologies and practices Policies measures and instruments Costing methodologies Global regional and national costs and ancillary benefits of mitigation Sector costs and ancillary benefits of mitigation Decision making frameworks