Representative Concentration Pathways (RCP) scenarios

Aimed at providing information to estimate greenhouse gas concentration to global circulation models, the RCP effort (van Vuuren et al., 2010a) see http://www.iiasa.ac.at/web-apps/tnt/RcpDb/dsd?Action=htmlpage&page=welcome) has been devised to assess emissions globally till 2100. An unmitigated and several mitigation pathways are being investigated. While the focus is on CO2 (half degree grid), information is provided for other greenhouse gases (CH4, N2O) and ozone precursors (NOx, NMVOC, CO) as well as SO2 and radiatively active PM (BC vs. OC). With a focus on climate effects, the depth of analysis for nitrogen compounds does not correspond to the needs for ECLAIRE. Moreover, as outlined in the “parallel process” devised for IPCC AR-5, the RCP’s describe a certain atmospheric radiation behavior but are currently lacking of underlying storylines – i.e. any technical or behavioral mitigation efforts cannot be described (Moss et al., 2010).

Nevertheless, as this is currently the only existing consistent scenario for oxidized sulfur and nitrogen compounds extending to 2100, it constitutes an important input to WP5. Moreover, some deposition maps for that date based on RCP emissions (trends 2050 to 2100 only) have been produced under ECLAIRE (D20.7). Shortcomings regarding overly optimistic technological developments have been noted in that exercise.


ECLIPSE V4 scenario

Based on global energy scenarios (World Energy Outlook till 2035, POLES model thereafter) and FAO agricultural projections (Alexandratos and Bruinsma, 2012), a new GAINS scenario has been developed which projects emissions for all GAINS regions globally until 2050 (Klimont et al., 2012). For Europe, more detailed data from PRIMES and CAPRI, respectively, have been included. Using the new gridding algorithm of GAINS, emission data have been made available as global emission fields (0.5°x0.5°) in NetCDF format. The data set includes four years (2005, 2010, 2030 and 2050) for nine substances and a sector split following RCP. The same scenario has been prepared for use across a range of related EU projects (PEGASOS, ECLIPSE) thus allowing for comparability of results.

 The underlying GAINS data (on a country resolution level, in 5-year time interval, allowing to choose from different sectoral attributions like the SNAP code or the NFR code) are accessible using the regular GAINS interface under the name “ECLIPSE_V4a_CLE_base” (internal ID: CP_WEO11_S10P50_v2). Access requires registration with the GAINS model.

 Emission data from this scenario, which includes no further emission abatement beyond currently adopted legal requirements (“current legislation”), have been forwarded to EMEP for use in the EMEP model. Model results (including deposition numbers based on this scenario) have been provided to the vegetation models, the DGVMs and DSVMs developed in ECLAIRE WP6 and intercompared in WP14. Results from these activities thus derive from the scenario described here, which was available early in the project. Also, NH3 projections from this scenario were provided to Task 6.3 (WP6).


ECLIPSE V5 scenario

Further developments in the GAINS model, which were i.a. based on consultations with countries during the TSAP process (Amann et al., 2014; 2015), lead to the implementation of revised parameters for abatement strategies and costs. While differences for a “current legislation” scenario are not important, abatement scenarios rely on these updates. Final assessments of the FP7 projects PEGASOS and ECLIPSE rely on these data (or on the V5a scenarios which cover further developments outside of Europe). The scenario is named “V5_ECLAIRE_CLE” and “V5_ECLAIRE_MFR” (for the maximum feasible reduction scenario) and is identical to “ECLIPSE_V5_CLE” and largely compatible with measures and costs reported to the Thematic Strategy on Air Pollution scenarios (Amann et al., 2015) and thus the European policy process.

This set of scenarios has been used in all exercises that considered emission abatement (WP18, WP19 and WP20). Some extensions were needed to cover decarbonization. These have been described in more detail in ECLAIRE D20.6.


Shared Socio-economic Pathways (SSPs)

Originally planned to provide storylines and harmonization to the “parallel process” to the RCP scenarios as input to IPCC’s AR5, completion of SSP’s took far longer time than expected. While results now are available for greenhouse gases (Nakicenovic et al., 2014), a consistent set of air pollution emissions that considers the range of possible future storylines is still in development (Shilpa Rao, personal information).