Assessing the consistency of institutional pathways with the Paris Agreement 

<p>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 present a uniform and transparent methodology to evaluate the climate outcome, and hence the Paris Agreement consistency of influential institutional emission scenarios from the grey literature, including those from the International Energy Agency^1,2, BP³, and Shell⁴. We first identify challenges to performing such an assessment and then proceed to outline a sequence of steps to address these challenges by harmonizing⁵ all emissions to a consistent base-year (2010), extending all pathways to 2100, and filling in missing emission species⁶. We employ two simple climate models, MAGICC⁷ and FaIR^8,9 to assess peak and end-of-century temperatures, and find that few published scenarios that claim to be compatible with the Paris Agreement are so.</p><p>&#160;</p><p><strong>References</strong></p><p><strong>&#160;1. </strong>International Energy Agency. World Energy Outlook 2020. (2020).</p><p>2. International Energy Agency. Net Zero by 2050 - A Roadmap for the Global Energy Sector. (2021).</p><p>3. BP. Global Energy Outlook 2020. (2020).</p><p>4. Shell. The Energy Transformation Scenarios. (2021)&#160;</p><p>5. Gidden, M. J. et al. A methodology and implementation of automated emissions harmonization for use in Integrated Assessment Models. Environ. Model. Softw. 105, 187&#8211;200 (2018)</p><p>6. Lamboll, R. D., Nicholls, Z. R. J., Kikstra, J. S., Meinshausen, M. & Rogelj, J. Silicone v1.0.0&#8239;: an open-source Python package for inferring missing emissions data for climate change research. Geosci. Model Dev 13, 5259&#8211;5275 (2020)</p><p>7. Meinshausen, M., Raper, S. C. B. & Wigley, T. M. L. Emulating coupled atmosphere-ocean and carbon cycle models with a simpler model, MAGICC6 - Part 1: Model description and calibration. Atmos. Chem. Phys. 11, 1417&#8211;1456 (2011).</p><p>8. Smith, C. J. et al. FAIR v1.3: A simple emissions-based impulse response and carbon cycle model. Geosci. Model Dev. 11, 2273&#8211;2297 (2018)</p><p>9. Millar, J. R., Nicholls, Z. R., Friedlingstein, P. & Allen, M. R. A modified impulse-response representation of the global near-surface air temperature and atmospheric concentration response to carbon dioxide emissions. Atmos. Chem. Phys. 17, 7213&#8211;7228 (2017).</p>