The Representative Concentration Pathways (RCP) define trajectories representing greenhouse gas, aerosol and chemical active gas concentrations as well as emissions from land use/land cover for particular climate projections (namely, radiative forcing values in the year 2100).  One emission scenario thus works on the basis of the global community agreeing to drastically reduce emissions of greenhouse gases. RCP8.5 represents a radiative forcing of 8.5 Watts per square metre by the end of the century. In between these two are other scenarios that entail greater or lesser degrees of technical advancement that would lead to slight reductions in greenhouse gases. The higher the radiative forcing value, the greater the change in climate conditions.