31 January 2007 GAINS Review Peringe Grennfelt Christer Agren Matti Johansson Rob Maas Simone Schucht Les White With comments from: Helen ApSimon Julio Lumbreras

Methodological changes (after CAFE-TS) Baseline & current policy definition Emission factors (cars, stoves) Increased background ozone Urban exposure (City-Delta, population data) Ecosystem dependent deposition rates More meteorological years Refinement of optimization method (from cost curves to individual technologies) GAINS Review phase I

GAINS Review phase I

GAINS Review phase I

An example cost curve for SO2 Source: IIASA GAINS Review phase I

Multi-pollutant measures Structural measures: Energy savings, efficiency improvements, bans: all pollutants ↓ Increased use of natural gas: CO2, SO2, VOC, NOx, PM ↓ CH4 ↑ Biomass: CO2 ↓ VOC, PM, CH4 ↑ Stationary sources: SCR, SNCR: NOx, CO ↓, NH3, N2O ↑ Fluidized bed combustion: SO2, NOx↓, N2O ↑ Advanced residential combustion: VOC, PM, CO, CH4 ↓ FGD: SO2, PM ↓ CO2 ↑ IGCC: CO2, SO2, NOx, PM ↓ CHP: all pollutants ↓ Mobile sources: Euro-standards: NOx, VOC, PM, CO ↓ NH3, N2O ↑ Low sulfur fuels: SO2, PM ↓ Diesel: CO2, VOC↓, PM, NOx, SO2 ↑ GAINS Review phase I

Differences between the RAINS and GAINS optimization RAINS optimization: Decides how far to move up the cost curve (keeping underlying activity levels fixed!) Cost curves are independent from each other Thus multi-pollutant measures are treated as single-pollutant GAINS optimization Decides which measure to use (incl. multi-pollutant) Each measure has one cost, but can have impacts on more than one pollutant If cost-effective and possible, change the underlying activity (through, e.g., efficiency improvements) GAINS Review phase I

GAINS Review phase I

Validation of RAINS cost curves with GAINS (the “RAINS-mode” of GAINS)- Italy, NOx, 2020 Source: IIASA GAINS Review phase I

Comparison of optimized results of GAINS with multi-pollutant measures treated as single pollutant measures (vertical) and as multi-pollutant measures (horizontal) Source: IIASA GAINS Review phase I

Conclusions GAINS (in RAINS mode) can replicate RAINS cost curves Optimization results are not very different Optimized results of GAINS (in RAINS mode) are as reliable as those of RAINS Warning: single pollutant cost curves generated by GAINS cannot be added ! GAINS Review phase I

The full GAINS mode offers further reduction potential (EU-25, 2020) Source: IIASA GAINS Review phase I

… and potential for cost reduction Source: IIASA GAINS Review phase I

Recommendations for review phase 2 (2007/2008) Keep informing policy makers on interactions between GHG and air pollution policies using the full GAINS mode Before official use of GAINS: schedule bilateral consultations on data used for GHG mitigation options and bilateral review of assumptions in PRIMES, TREMOVE & CAPRI scenarios Compare GAINS results with other (national) models that integrate GHG and air pollutant abatement Organize a peer review with experts from the energy and climate community focused on the treatment of GHG mitigation options Organize a full review in 2009 GAINS Review phase I