it also assesses the impacts of coal and gasfired power with carbon capture and storage ccs the impacts of these technologies are compared with those of modern coal and gasfired power without ccs but with stateoftheart pollution control bioenergy is not included because it is covered in a recent irp report bringezu et al nuclear power generation is not included because unep sees this technology as being under the responsibility of a different un agency iaea oil fired steam power plants were excluded because they are seen as less relevant for the future