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: RCP2.6 scenario assumes an additional radiative of 2.6 Watts per square metre by the end of the 21st century. Another scenario represents a situation in which humans continue in the same way as we have to date, emitting ever more greenhouse gases.