16 August, 2022

Institutional decarbonisation scenarios evaluated against the Paris Agreement 1.5°C goal


Robert Brecha, Gaurav Ganti, Robin Lamboll, Zebedee Nicholls, Bill Hare, Jared Lewis, Malte Meinshausen, Michiel Schaeffer, Christopher Smith, Matthew Gidden

This study analyses six institutional decarbonisation scenarios published between 2020 and mid-2021, including four from the oil companies BP, Royal Dutch Shell and Equinor (two from BP), and two developed by the International Energy Agency IEA. It finds that most of the scenarios would be classified as inconsistent with the Paris Agreement as they fail to limit warming to ‘well below 2°C’, let alone 1.5°C, and would exceed the 1.5°C warming limit by a significant margin.

Scientifically rigorous guidance to policy makers on mitigation options for meeting the Paris Agreement long-term temperature goal requires an evaluation of long-term global-warming implications of greenhouse gas emissions pathways.

Here we employ a uniform and transparent methodology to evaluate Paris Agreement compatibility of influential institutional emission scenarios from the grey literature, including those from Shell, BP, and the International Energy Agency. We compare a selection of these scenarios analysed with this methodology to the Integrated Assessment Model scenarios assessed by the Intergovernmental Panel on Climate Change. We harmonize emissions to a consistent base-year and account for all greenhouse gases and aerosol precursor emissions, ensuring a self-consistent comparison of climate variables. An evaluation of peak and end-of-century temperatures is made, with both being relevant to the Paris Agreement goal.

Of the scenarios assessed, we find that only the IEA Net Zero 2050 scenario is aligned with the criteria for Paris Agreement consistency employed here. We investigate root causes for misalignment with these criteria based on the underlying energy system transformation.