Representative Concentration Pathways (RCPs)

What is a Representative Concentration Pathway (RCP)?

Representative Concentration Pathways (RCPs) are scenarios developed by scientists to model potential future emissions pathways based on varying levels of greenhouse gas (GHG) emissions. These pathways help predict how different emission scenarios could affect global temperatures by the year 2100, guiding us in understanding the possible outcomes of our current emission trends and the impact of taking decisive actions to reduce emissions.

Understanding RCP Scenarios and Temperature Projections

The original RCP scenarios ranged from RCP2.6, aiming to significantly limit global warming from between 1.5°C to 2°C, to RCP8.5, assuming high emissions continue, leading to considerable temperature increases. Since then, an additional scenario has been added, RCP1.9, which builds on RCP2.6 by specifically representing an ambitious scenario aiming to keep global warming below 1.5°C. Here is a list of the RCPs:

RCP1.9: The most optimistic scenario, aiming to limit global warming to 1.5°C above pre-industrial levels. This scenario requires rapid and significant reductions in GHG emissions and is in line with achieving the goals of the Paris Agreement.
RCP2.6: Projects a temperature increase of 1.5°C to 2°C, aligning with goals to limit warming well below 2°C.
RCP4.5 and RCP6.0: Intermediate scenarios predict temperature rises of 2°C to 3°C, indicating that some actions have been taken to curb emissions, but not enough to meet the Paris Agreement's ambitious 1.5°C target.
RCP8.5: This scenario suggests a potential temperature rise of more than 4°C if minimal mitigation efforts are undertaken, leading to severe climate impacts.

Whats the difference between Representative Concentration Pathways (RCPs) and Shared Socioeconomic Pathways (SSPs)?

Representative Concentration Pathways (RCPs) differ from Shared Socioeconomic Pathways (SSPs) in that:

RCPs are only focused on the outcomes of different greenhouse gas concentration trajectories and their resulting radiative forcing
RCPs are used for physical climate modelling
SSPs provide narratives that describe how global society might evolve in ways that could lead to those different RCPs.
SSPs are employed to understand the socioeconomic choices that drive those climate outcomes, allowing for a broader analysis of potential mitigation and adaptation strategies.

How do RCPs Tie into the SBTi and IPCC?

The Science-Based Targets initiative (SBTi) and the Intergovernmental Panel on Climate Change (IPCC) use these RCP scenarios to guide businesses and governments in setting scientific and practical targets for emissions reductions.

The SBTi encourages companies to set targets that reduce their GHG emissions in line with the decarbonisation required to keep global temperature increase below 2°C, aiming for 1.5°C, compared to pre-industrial levels. Aligning with RCP1.9 or RCP2.6, businesses can ensure they are on a path to sustainability that aligns with the scientific consensus necessary to avert the most catastrophic impacts of climate change.
The IPCC provides the scientific basis for understanding the potential impacts of different warming scenarios, including those outlined by RCP1.9 and other RCPs. This information is crucial for international climate negotiations and helps inform policy decisions and climate action plans.