Representative Concentration Pathway

All forcing agents CO2 equivalent concentration

Representative Concentration Pathways (RCPs) are climate change scenarios that were developed for the Intergovernmental Panel on Climate Change (IPCC) Fifth Assessment Report (AR5) in 2014. The RCPs describe four different 21st century pathways of greenhouse gas emissions and atmospheric concentrations, air pollutant emissions, and land use changes. Each pathway represents a different scenario of greenhouse gas concentration (not emissions) trajectories adopted based on their radiative forcing values by the year 2100, ranging from 2.6 to 8.5 watts per square meter (W/m^2).

Overview

The concept of RCPs is a central component in the climate change literature, providing a framework for researchers to analyze the impacts of climate change and to develop strategies for mitigation and adaptation. The RCPs are used in climate models and projections to assess the range of possible future climates based on current and potential future greenhouse gas emission trajectories.

The Four RCPs

The four RCPs, named after their radiative forcing target for the year 2100, are:

• RCP2.6: Aims for a very stringent mitigation scenario, leading to a peak in greenhouse gas concentrations around 2020, with a substantial decline thereafter.
• RCP4.5 and RCP6.0: Represent stabilization scenarios after 2100, without exceeding the specified radiative forcing levels.
• RCP8.5: Represents a high greenhouse gas emissions scenario, in which emissions continue to rise throughout the 21st century.

Development and Use

The RCPs were developed through an integrated assessment modeling approach, combining knowledge from the fields of economics, energy, agriculture, and climate science. They are not predictions but are instead intended to cover a range of possible futures to inform policy and decision-making.

Implications for Climate Change Research

The RCPs have significantly contributed to the understanding of potential future climates and have been extensively used in climate change impact assessments, including the IPCC's Fifth and Sixth Assessment Reports. They provide a basis for exploring how different levels of mitigation could impact global warming, sea-level rise, and other climate change effects.

Criticism and Future Directions

While the RCPs have been instrumental in climate change research, they have also faced criticism for their assumptions and for the lack of a scenario with negative emissions by the end of the century. Future pathways, known as Shared Socioeconomic Pathways (SSPs), have been developed to address these and other limitations by combining RCPs with socioeconomic narratives.

See Also

• Climate change mitigation
• Climate model
• Global warming
• Intergovernmental Panel on Climate Change
• Shared Socioeconomic Pathways