A Representative Concentration Pathway is a greenhouse gas concentration (not emissions) trajectory adopted by the IPCCIPCC The Intergovernmental Panel on Climate Change is the United Nations body for assessing the science related to climate change. It produces periodical reports, called 'Assessment Reports', which have an important role to play in informing international policy making. The most recent report is the 6th Assessment Report.. Four pathways were used for climate modeling and research for the IPCC fifth Assessment Report in 2014. The pathways describe different climate futures, all of which are considered possible depending on the volume of greenhouse gases emitted in the years to come.