Future emissions (ScenarioMIP) Co-chairs: Brian O’Neill; Claudia Tebaldi; Detlef van Vuuren Scientific Steering Committee: Pierre Friedlingstein; George Hurtt; Reto Knutti; Jean-Francois Lamarque; Jason Lowe; Jerry Meehl; Richard Moss; Ben Sanderson; Veronica Eyring

Goal ScenarioMIP: Simulate future climate outcomes based on alternative plausible future scenarios 1. Facilitating integrated research across climate science, IAM and IAV communities. 2. Anchoring targeted experiments (e.g land-use change/air chemistry) to answer questions about specific forcings. Core ScenarioMIP Together with LUMIP, CMIP etc RCPs Climate SSPs Impact Exposed population, ability to adapt Drivers (population, GDP) Energy use, Land use Emissions Conc./ forcing Climate/ Environmental change

The Scenario Matrix Architecture SSP1 SSP2 SSP3 Shared Socio-economic Pathways SSP4 SSP5 RCPs Forcing level (W/m2) 8.5 6.0 4.5 2.6 Climate SSPs

The Scenario Matrix Architecture Shared Socio-economic Pathways SSP1 SSP2 SSP3 SSP4 SSP5 Challenge to mitigation Challenge to adaptation

SSPs (Energy) SSP5 (Fossil-fueled growth) SSP3 (Regional rivalry) SSP2 1850 1900 1950 2000 2050 2100 EJ 500 1000 1500 2500 Other renewables Nuclear Gas Oil Coal Biomass SSP3 (Regional rivalry) SSP5 (Fossil-fueled growth) 1850 1900 1950 2000 2050 2100 EJ 500 1000 1500 2500 Other renewables Nuclear Gas Oil Coal Biomass SSP2 (Middle of the road) 1850 1900 1950 2000 2050 2100 EJ 500 1000 1500 2500 Other renewables Nuclear Gas Oil Coal Biomass SSP1 (Sustainability) SSP4 (Inequality)

The Scenario Matrix Architecture Forcing level (W/m2) 8.5 6.0 4.5 2.6 SSP1 SSP2 SSP3 Shared Socio-economic Pathways SSP4 SSP5

ScenarioMIP Experimental Design Tier 1 SSP5-8.5 Continuity with CMIP5 and representative of high end of range. SSP3-7 Filling the gap; Representative of many unmitigated SSP baseline scenarios. Interesting afforestation/airpollution burden (LUMIP/AerChemMIP) SSP2-4.5 Continuity with CMIP5 and interest from CORDEX/Decadal Prediction/DAMIP. SSP1-2.6 Continuity with CMIP5 and representative of low end of range. Tier 2 SSP1-6.0 Continuity SSP4-3.7 Filling the Gap (interesting mitigation target less stringent than RCP2.6) Overshoot scenario SSP3-7 ensemble enriching the exploration of internal variability. Long-term extensions (3) to address slow-response components of the climate system (ice sheet, sea level rise). Overshoot Ext. Ens Ext + OS. Tier3 -> 1.5oC scenario

World CO2 Emissions Harmonisation with historic emission and concentration range Translation of future emissions into concentration

Reference scenarios, relative to 2005 = 1) Land maps Reference scenarios, relative to 2005 = 1) 1.5 IAM range SSP marker Cooperation with George Hurtt to translate these into harmonised maps SSP3 1.4 High population & low agr. productivity 1.3 SSP5 1.2 SSP2 SSP4 million ha (2005=1) 1.1 1.0 Sustainable development SSP1 0.9 0.8 0.7 2000 2020 2040 2060 2080 2100

World Sulfur Emissions 2000 2020 2040 2060 2080 2100 Sulfur (MtS) 20 40 60 80 100 120 140 160 IAM teams translate these into scenarios of future emissions based on gridded historical emissions? Coordinated effort to create concentration data IAM range SSP marker RCPs SSP3 SSP2 SSP4 SSP5 SSP1

Process 2012 2013 2014 2015 2016 2017 Oct. 2016? I PCC Mee t ng WG1, WG2, WG3 representatives: design of assessment scheme Oct. 2016? I PCC Mee t ng March 2016 IAM teams : quantified scenarios 2.0W/m2 Overshoot ScenarioMIP runs ScenarioMIP Harmonised land use Historical data Jan 2016 Harmonised emissions Atm. Chemistry runs Extensions 13 november 2018 Special Issue

Questions? 13 november 2018

Data availability and resolution All data publicly accessible at the SSP database National data (since 2013): GDP Population (structure, education, tot) Urbanization IAM scenario data (for illustration) Energy Land-use Emissions Forcing & Temperature Other relevant indicators (carbon price, economic feedbacks, etc..) Resolution: 5 World Regions (more details available from IAM teams 10-26 regions) https://secure.iiasa.ac.at/web-apps/ene/SspDb Add UCAR page and names from the ICONICS committee

Characteristics: Small number (3 in Tier 1) In each tier a High, Medium and Low by 2100 Tier 1 still spans a plausible high/low(2oC) range; 6.0 is seen as what would come from current policies Tier 2: 7.0 important for impact assessment; 3.7 considered an important mitigation target; updates 4.5. Updated drivers support IAM/IAV research into the 2020’s through not only new IAM and climate models but new socio-economic assumptions. Variants of the same scenarios can be used to explore targeted questions about sensitivity to LUC, SLCF and overshoot. ** it may be (or may be not) worth making the point that the proposal can be read as updating the 4 RCPs and adding two new forcing levels – but we don’t want to undersell it!

Additional Issues We recommend concentration driven (better constraining forcing levels and thus making integrated research easier to compare and summarize across studies) We recommend concentrating IC ensemble members for one scenario only (RCP8.5? RCP4.5? Depending possibly on other MIPs recommended experiments) We are interested in long-term extensions, TBD

Time-line 2014 2016 2015 ScenarioMIP proposal / Garmisch IAM model runs open review Finalisation IAM model runs, IPCC conference Decisions on scenarios Data available after harmonisation, downscaling etc