Scenarios that include time series of emissions and concentrations of the full suite of greenhouse gases and aerosols and chemically active gases, as well as land use/land cover (Moss et al., 2008)1. The word representative signifies that each RCP provides only one of many possible scenarios that would lead to the specific radiative forcing characteristics. The term pathway emphasizes that not only the long-term concentration levels are of interest, but also the trajectory taken over time to reach that outcome (Moss et al., 2010)2.
1 Moss, Richard H.; Babiker, Mustafa; Brinkman, Sander; Calvo, Eduardo; Carter, Tim; Edmonds, James A. et al. (2008): Towards new scenarios for analysis of emissions, climate change, impacts, and response strategies. IPCC Expert Meeting Report. Intergovernmental Panel on Climate Change (IPCC). Geneva, Switzerland. Available online at https://www.osti.gov/etdeweb/biblio/949784.
2 Moss, Richard H.; Edmonds, Jae A.; Hibbard, Kathy A.; Manning, Martin R.; Rose, Steven K.; van Vuuren, Detlef P. et al. (2010): The next generation of scenarios for climate change research and assessment. In Nature 463 (7282), pp. 747–756. DOI: 10.1038/nature08823.