New PCIC Science Brief: on Paris Climate Accord Emissions and Temperature Limits

PCIC is pleased to announce the release of our next Science Brief. PCIC Science Briefs are a regular series of brief reports on recent climate science literature, relevant to stakeholders in British Columbia and surrounding areas. PCIC has developed these briefs because it recognizes the need for a bridge between the cutting edge of climate science research and the various stakeholders who need access to this knowledge, in plain-language reports, filtered for regional relevance, and suitable for consideration in planning and adaptation. PCIC Science Briefs contextualize and explain the results and implications of important scientific findings.

In order to minimize the potential impacts of anthropogenic climate change, 196 countries met in Paris, France, in the winter of 2015 for the 21st Conference of the Parties of United Nations Framework Convention on Climate Change. There they negotiated a global agreement on reducing and limiting humanity's greenhouse gas emissions. The resulting Paris Agreement aims to limit global warming to 2°C by the end of the century as compared to the preindustrial period, and ideally 1.5°C. 

PCIC's latest Science Brief covers three recent articles from the journal Nature Climate Change that examine greenhouse gas emissions budgets and pathways consistent with these warming limits. Using global climate model projections, Tokarska and Gillett (2018) calculate a new median remaining carbon budget of 208 billion tonnes from January 2016 that is consistent with limiting warming to 1.5°C. Tanaka and O'Neill (2018) use an integrated assessment model and find that meeting the Paris temperature limits may not require net zero greenhouse gas emissions, that reducing emissions to zero doesn't necessarily result in meeting the Paris temperature limits by the end of the century, and that imposing both temperature and emissions limits causes temperatures to decline after meeting the initial temperature limit. Using an integrated assessment model van Vuuren et al. find that implementing strategies such as making large-scale lifestyle changes and using efficient technologies for the production of energy and materials can slightly reduce, but not eliminate, the need for negative emissions.

Read the new Science Brief.

Tanaka, K. and B.C. O’Neill, 2018: The Paris Agreement zero-emissions goal is not always consistent with the 1.5 °C and 2 °C temperature targets. Nature Climate Change, 8, 319–324, doi:10.1038/s41558-018-0097-x.

Tokarska, K.B. and N.P. Gillett, 2018: Cumulative carbon emissions budgets consistent with 1.5 °C global warming.  Nature Climate Change, 8, 296–299, doi:10.1038/s41558-018-0118-9.

van Vuuren, D.P. et al., 2018: Alternative pathways to the 1.5 °C target reduce the need for negative emission technologies. Nature Climate Change, 8, 391–397, doi:10.1038/s41558-018-0119-8.