Representative Concentration Pathways
Future climate model simulations need to take into consideration how world development will progress and its associated emissions and concentration of greenhouse gases, aerosols, and land use change. However, we are unable to predict how this development will unfold over time, as it depends on a range of technological, socio-economic, and political factors.
Representative concentration pathways (RCPs) are scenarios used to help characterize this uncertainty in climate models so we can generate data about possible future climates.
RCPs were developed by a group of experts in areas spanning atmospheric modelling, chemistry, and the carbon cycle, and social scientists working on economics, policy, and impacts[1].
There are four RCPs, defined on the basis of radiative forcing pathways and level in 2100. Radiative forcing is a measure of the Earth’s energy balance. It is affected by greenhouse gas and aerosol concentrations, changes in land cover, and solar energy.
| RCP | Description |
| RCP8.5 | Rising radiative forcing pathway leading to 8.5 W/m2 (~1370 ppm CO2 eq) by 2100 |
| RCP6 | Stabilization without overshoot pathway to 6 W/m2 (~850 ppm CO2 eq) at stabilization after 2100 |
| RCP4.5 | Stabilization without overshoot pathway to 4.5 W/m2 (~650 ppm CO2 eq) at stabilization after 2100 |
| RCP2.6 | Peak in radiative forcing at ~3 W/m2 (~490 ppm CO2 eq) before 2100 and then decline (the selected pathway declines to 2.6 W/m2 by 2100) |
Source: [2]
[1] Moss R, Edmonds J, Hibbard K et al. 2010. The next generation of scenarios for climate change research and assessment. Nature, 463, 747-756.
[2] van Vuuren DP, Edmonds J, Kainuma M et al. 2011. The representative concentration pathways: an overview. Climatic Change, 109: 5. doi:10.1007/s10584-011-0148-z