Guidance on emissions metrics for Nationally Determined Contributions under the Paris Agreement

Code and data for Guidance on emissions metrics for nationally determined contributions under the Paris Agreement

Steve Denison, Piers M Forster and Christopher J Smith

Published 18 November 2019 • © 2019 The Author(s). Published by IOP Publishing Ltd Environmental Research Letters, Volume 14, Number 12

Citation: Denison, S., Forster, P. M. and Smith, C. J., 2019. Guidance on emissions metrics for nationally determined contributions under the Paris Agreement. Environmental Research Letters, 14 (12), DOI https://doi.org/10.1088/1748-9326/ab4df4

Requirements

• The dependencies used to produce the code and data is given in REQUIREMENTS.txt.
• We used python 3.7.10 in a miniconda environment. virtualenv should give the same results. This is how we did it in conda:

$ conda create --name denison19 python=3.7
$ conda activate denison19
$ pip install -r REQUIREMENTS.txt

Reproducing the figures and results

All of the code needed to generate the results is given in the Jupyter notebooks.

1. pre-processing: making the emissions scenarios. Save as hierarchical HDF5 files.
2. crunching - output temperatures from 21st century. Save full output as netCDF. This takes several hours to run.
3. process with 2000-2100 median temperatures from each scenario into HDF5 files for plotting (the HDF files do not contain the full information from the netCDFs and are much smaller.
4. figure plotting

Both an 'a' and a 'b' stream are given. The 'a' stream uses the default FaIR atmospheric burden lifetime of methane of 9.3 years. The 'b' stream uses the metric perturbation lifetime of 12.4 years. All data and figures produced using the 12.4 lifetime are appended with '12.4'.

Acknowledgements and references

This code uses raw data that was used in the IPCC's Special Report on 1.5C. The same data is now publicly available from the IAMC 1.5C Scenario Explorer, though we used an earlier, non-public form (MAGICC6 SCEN files).

1. Huppmann, D., E. Kriegler, V. Krey, K. Riahi, J. Rogelj, K. Calvin, F. Humpenoeder, A. Popp, S. K. Rose, J. Weyant, N. Bauer, C. Bertram, V. Bosetti, J. Doelman, L. Drouet, J.s Emmerling, S. Frank, S. Fujimori, D. Gernaat, A. Grubler, C. Guivarch, M. Haigh, C. Holz, G. Iyer, E. Kato, K. Keramidas, A. Kitous, F. Leblanc, J.-Y. Liu, K. Löffler, G. Luderer, A. Marcucci, D. McCollum, S. Mima, R. D. Sands, F. Sano, J. Strefler, J. Tsutsui, D. Van Vuuren, Z. Vrontisi, M. Wise, and R. Zhang, 2019: IAMC 1.5°C Scenario Explorer and Data hosted by IIASA. Integrated Assessment Modeling Consortium & International Institute for Applied Systems Analysis, 2019. https://10.5281/zenodo.3363345
2. Rogelj, J., D. Shindell, K. Jiang, S. Fifita, P. Forster, V. Ginzburg, C. Handa, H. Kheshgi, S. Kobayashi, E. Kriegler, L. Mundaca, R. Séférian, and M.V. Vilariño, 2018: Mitigation Pathways Compatible with 1.5°C in the Context of Sustainable Development. In: Global Warming of 1.5°C. An IPCC Special Report on the impacts of global warming of 1.5°C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty [Masson-Delmotte, V., P. Zhai, H.-O. Pörtner, D. Roberts, J. Skea, P.R. Shukla, A. Pirani, W. Moufouma-Okia, C. Péan, R. Pidcock, S. Connors, J.B.R. Matthews, Y. Chen, X. Zhou, M.I. Gomis, E. Lonnoy, T. Maycock, M. Tignor, and T. Waterfield (eds.)]. In Press.