HELIX supported the production of the IPCC Special Report on 1.5°C in several important ways.

1.    The decision by the IPCC to go ahead with the report

With the adoption of the Paris Agreement in 2015, the United Nations Framework Convention on Climate Change (UNFCCC) invited the IPCC to provide a Special Report in 2018 on the impacts of global warming of 1.5°C above pre–industrial levels and related global greenhouse gas emissions pathways. This was one of 31 proposals for various special reports to be considered by the IPCC, but only three could be produced due to limits on resources.  A key factor in deciding whether the proposed 1.5°C report could be delivered was whether there would be enough peer-reviewed scientific papers to form the basis of the report. The European Commission (EC) held discussions with the IPCC leadership to assess whether existing EC-funded projects could re-orient part of their work plans in order to publish 1.5°C-relevant results in time to be included in the proposed report.  Prof. Richard Betts, as HELIX director, attended these discussions and gave a keynote presentation on possible research on the impacts at 1.5°C.  Although at this point HELIX was only 18 months away from completion, the project’s experimental design already framed its analysis in terms of levels of global warming, initially at 2°C, 4°C and 6°C, and the design was flexible enough to allow results at 1.5°C to be produced as well.  As a result of supportive responses from the research community including HELIX, the IPCC Board recommended its member governments to commission the 1.5°C Special Report and the decision was made in April 2016.


2.    New research comparing the impacts of climate change at 1.5°C and 2°C

A number of peer-reviewed papers were published by HELIX specifically addressing the issue of 1.5°C global warming. Some of these were cited in the IPCC Special Report, along with other HELIX papers from earlier in the project which provided further background, informing the report on river flood risk, biodiversity, food insecurity, carbon emissions and tipping points amongst other topics:

– Alfieri, L. et al., 2017: Global projections of river flood risk in a warmer world. Earth’s Future, 5(2), 17

– Alfieri, L., F. Dottori, R. Betts, P. Salamon, and L. Feyen, 2018: Multi-Model Projections of River Flood Risk in Europe under Global Warming. Climate, 6(1)(6).

– Betts, R.A. et al., 2018: Changes in climate extremes, fresh water availability and vulnerability to food insecurity projected at 1.5°C and 2°C global warming with a higher-resolution global climate model. Philosophical Transactions Royal Society A, 376(2119)

– Friedlingstein, P. et al., 2014a: Persistent growth of CO2 emissions and implications for reaching climate targets. Nature Geoscience, 7(10), 709-715

– Frieler, K. et al., 2017: Assessing the impacts of 1.5°C global warming – simulation protocol of the Inter-Sectoral Impact Model Intercomparison Project (ISIMIP2b). Geoscientific Model Development

– Grillakis, M.G., A.G. Koutroulis, I.N. Daliakopoulos, and I.K. Tsanis, 2017: A method to preserve trends in quantile mapping bias correction of climate modeled temperature. Earth System Dynamics, 8, 889-900

– Le Quéré, C. et al., 2018: Global Carbon Budget 2017. Earth System Science Data, 10(1), 405-448

– Lontzek, T.S., Y. Cai, K.L. Judd, and T.M. Lenton, 2015: Stochastic integrated assessment of climate tipping points indicates the need for strict climate policy. Nature Climate Change, 5(5), 441-44

– Mohammed, Khaled, A.K.M. Saiful Islam,  M. Tarekul Islam, G & Alfieri, Lorenzo, Kumar Bala, Sujit, Khan, Md Jamal Uddin. (2017) “Extreme flows and water availability of the Brahmaputra River under 1.5 and 2 °C global warming scenarios” Climatic Change doi 10.1007/s10584-017-2073-2

– Schleussner, C.F. et al., 2016: Science and policy characteristics of the Paris Agreement temperature goal. Nature Climate Change, 6, 827-835

– Smith, P., J. Price, A. Molotoks, R. Warren, and Y. Malhi, 2018: Impacts on terrestrial biodiversity of moving from a 2°C to a 1.5°C target. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 376(2119), 20160456

Figure 3.15 in the Report, on projected changes in global river flows at 1.5C and 2C, was reproduced from Betts et al (2018) having been created by Dr. Aris Koutroulis of the Technical University of Crete.


3.    Authors and reviewers of the IPCC Special Report

HELIX scientist Prof. Rachel Warren, of the Tyndall Centre at the University of East Anglia, served as a Lead Author on the Special Report and Prof. Tim Lenton of the University of Exeter served as Contributing Author.  The team of 91 authors from 40 countries put in a huge amount of dedicated effort and the HELIX project thanks and congratulates them on their successful endeavour.  A number of other HELIX scientists provided expert review comments on drafts of the report.


4.    Guidance on data visuals

HELIX’s Engagement and Communication Work Package includes a sub-project requested by the IPCC and co-funded by the Norwegian Environment Agency to provide a guide for improved graphics. The work was led by Jordan Harald and Asher Minns of the Tyndall Centre.


5.  Hosting a meeting of the IPCC authors

Production of the report involved 4 major week-long meetings for the authors and editorial team, to discuss key issues in preparing drafts and acting on review comments. One of these Lead Author meetings was held at the University of Exeter and Met Office, hosted by HELIX director Prof. Richard Betts and his colleagues at both organisations.  It was a pleasure and a privilege to host such an esteemed team of international scientists.


6.    Public discussion of the report on its launch

HELIX members were involved in a number of activities to publicise the report and stimulate discussion following its launch.  Prof. Betts appeared on prime-time TV news in the UK on the ITV News at Ten and The Weather Show on BBBC Radio and Prof. Saiful Islam at the Bangladesh University of Engineering and Technology convened an outreach event in Bangladesh which achieved further coverage.  Prof. Betts took part in a discussion in The Weather Studio show on the Met Office’s YouTube Channel, and a further Met Office video released on social media. Prof. Corinne Le Quéré gave an interview for BBC News on the day the Report was launched. For the European launch, hosted in London, Prof. Rachel Warren presented the conclusions of impacts at 1.5°C compared to 2°C in her speech, Asher Minns spoke about behaviour and public engagement with the conclusions of the Report. .