RCP2.6

RCP2.6
Name	RCP2.6
Alternative names	RCP 2.6, RCP2p6
Developed by	Intergovernmental Panel on Climate Change
Year	2011
Peak forcing	2.6 W/m2
Target temperature	~1.5–2 °C by 2100 (varies)
Key features	rapid emissions reductions, net negative emissions

RCP2.6 is a representative concentration pathway characterized by ambitious greenhouse gas reductions that produce a radiative forcing of about 2.6 watts per square meter by 2100. It was developed for use in the Fifth Assessment Report of the Intergovernmental Panel on Climate Change and is associated with scenarios aiming to limit global warming to near 1.5–2 °C relative to preindustrial levels. The pathway assumes early peaking of carbon dioxide emissions and deployment of negative‑emission technologies, informing assessments by scientific bodies, international agreements, research institutions, and modelling centers.

Overview

RCP2.6 emerged from collaborations among climate scientists at institutions linked to the Intergovernmental Panel on Climate Change, National Aeronautics and Space Administration, National Oceanic and Atmospheric Administration, Met Office Hadley Centre, and the Potsdam Institute for Climate Impact Research. It contrasts with higher forcing scenarios used by groups such as the International Energy Agency, World Meteorological Organization, European Commission, Lawrence Livermore National Laboratory, and IPCC Working Group I authors. The pathway underpinned analysis in major assessments alongside scenarios like those used by International Institute for Applied Systems Analysis, IIASA MESSAGE, MIT Energy Initiative, Grantham Institute, and the Stockholm Environment Institute. RCP2.6 informs modelling studies involving the Community Earth System Model, HadGEM, CMIP5, CMIP6 comparisons, and integrated assessment models developed at Princeton University, Paul Scherrer Institute, and Tsinghua University.

Climate Projections and Methodology

Climate projections using this pathway combine outputs from general circulation models at centers such as NASA GISS, NOAA GFDL, Met Office, Max Planck Institute for Meteorology, CSIRO, Institut Pierre-Simon Laplace, and Geophysical Fluid Dynamics Laboratory. These models produce projections of temperature, precipitation, sea level, and extreme events used by analysts at United Nations Framework Convention on Climate Change, World Bank, International Panel on Biodiversity and Ecosystem Services, and United Nations Environment Programme. Methodology integrates radiative forcing targets with integrated assessment models from IIASA, MESSAGE-GLOBIOM, IMAGE, REMIND, and GCAM to derive emissions trajectories for United States Environmental Protection Agency-style inventories, carbon budgets cited by SR15 authors, and scenario ensembles used in Coupled Model Intercomparison Project experiments.

Emission Pathways and Assumptions

Assumptions for this pathway involve rapid declines in carbon dioxide, methane, and aerosol precursor emissions consistent with energy transformations studied by International Energy Agency, BP Statistical Review, Shell scenarios team, Chevron, and national policy programmes like those of European Union, China, United States, India, and Japan. The pathway typically requires large-scale adoption of technologies evaluated by Intergovernmental Panel on Climate Change mitigation authors, including carbon capture and storage demonstrated in pilot sites such as those reported by Sleipner, Boundary Dam, Kemper County energy facility (as discussed in energy literature), and bioenergy with carbon capture and storage scenarios examined by Drax Group-related studies. Land‑use assumptions draw on work from Food and Agriculture Organization, International Union for Conservation of Nature, and Copenhagen Consensus-style analyses.

Impacts and Mitigation Implications

Under the pathway, projected impacts on ecosystems, agriculture, and infrastructure have been analysed by teams at Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, World Health Organization, Food and Agriculture Organization, and United Nations Office for Disaster Risk Reduction. Limiting warming near the pathway’s range reduces risks assessed in reports by IPCC Special Report on Global Warming of 1.5 °C, World Bank Climate Change Action Plan, and adaptation studies from Asian Development Bank and African Development Bank. Mitigation implications include rapid decarbonization of sectors covered in policy dialogues at G20, UNFCCC Conference of the Parties, European Commission Green Deal, and national pledges like those submitted under Paris Agreement-era processes.

Policy Responses and Use in Assessments

RCP2.6 has been used by policy makers and analysts at institutions such as European Commission, UNFCCC, Organisation for Economic Co-operation and Development, United Nations Development Programme, and national agencies for scenario planning and risk assessment. It informed cost‑benefit and integrated policy studies involving authors from Harvard University, Stanford University, Yale University, Princeton University, and Imperial College London. The scenario underpins modelling of mitigation pathways in reports by IPCC Working Group III, energy outlooks by International Energy Agency, and climate finance analyses by World Bank and International Monetary Fund.

Criticisms and Uncertainties

Critics from research groups including Resources for the Future, Stockholm Environment Institute, Centre for Policy Research, Global Carbon Project, and scholars at University of Oxford argue that assumptions about negative emissions draw on contested feasibility studies, citing uncertainty in scaling technologies like bioenergy with carbon capture and storage and direct air capture developed in laboratories at Carnegie Mellon University and ETH Zurich. Uncertainties also arise in climate sensitivity estimates debated in literature from Royal Society, National Academies of Sciences, Engineering, and Medicine, and modelling variance across CMIP5 and CMIP6 ensembles. Policy critiques reference negotiation outcomes at UNFCCC Conferences of the Parties and economic analyses by OECD and IMF concerning costs, equity, and technological readiness.

Category:Climate change scenarios