Long term assessment of the global impact of CO 2 aviation emissions under various scenarios in the frame of the IMPACT project

Transcription

1 Long term assessment of the global impact of CO 2 aviation emissions under various scenarios in the frame of the IMPACT project Etienne TERRENOIRE Didier HAUGLUSTAINE Thomas GASSER Olivier PENANHOAT FORUM-AE Workshop on Inventories & Long-Term Projections 1-2 September 2015 Zurich Switzerland

2 The climate system = multiple interactions of different natural/anthropogenic activities Moss et al., 2012 (Nature) The climate system is complex! 2

3 48 months project funded by Direction Générale de l Aviation Civile (DGAC) in the framework of the COnseil pour la Recherche Aéronautique et Civile (CORAC). Start : 11/2012 IMPACT of aircraft emissions on present and future climate 5 partners (public and private) in the project : Didier Hauglustaine, Etienne Terrenoire Laboratoire des Sciences du Climat et de l Environnement, CNRS, Gif sur Yvette Olivier Boucher Laboratoire de Météorologie Dynamique (LMD), CNRS, Paris Philippe Ricaud CNRM-GAME, Météo-France, CNRS, Toulouse Daniel Cariolle CERFACS, Toulouse Olivier Penanhoat SAFRAN Snecma, Villaroche Website: 3

4 IMPACT project main objectives Lee et al., AE, 2009 The IMPACT project aims to contribute reducing uncertainties in calculating the climate impact of aircraft emissions and in particular those associated with: - contrails and induced cirrus - Nox emissions (impact on methane and ozone) - Aerosols (sulfates, nitrates, soot). 4

5 Outline 1- Presentation of the OSCAR v2.1 model 2- Application of OSCAR to the IMPACT project Quantify the impact of aircraft emissions (CO 2, NOx (CH 4, O3), BC, SO 2 (sulfates, nitrates), contrails, cirrus) on temperature. 3- Results for CO 2 emissions: Two aviation emissions scenarios for the period RCP6 and RCP8.5 scenarios as background for CO 2 ( ) 4- Summary and next steps 5

6 1- Introduction to OSCAR v2.1 OSCAR v1 was a carbon cycle model developed by Gitz and Ciais, Now OSCAR v2.1 (further developments including python recoding and the introduction of other species (Gasser s PhD, 2014)). OSCAR is a Simplified Climate Model (SCM) Interaction of different meta-model (ex: atmosphere, biosphere, ocean, land-use) calibrated against complex climate models outputs (CMIP5 s models) available in the literature. Model the anthropogenic perturbation for different species with respect to theirs pre-industrial concentrations (1750): CO 2, CH 4, N 2 O, (H)CFC, O 3, (sulphates, nitrates, BC/OC). 1 Gitz, V. & Ciais, P. (2003). Amplifying effects of land-use change on future atmospheric CO2 levels. Global Biogeochemical Cycles, 17(1). 6

7 1- The carbon cycle in OSCAR v2.1 ATMO OCEAN BIOSPHERE LAND USE In red: direct forcing In black: indirect forcing From Gasser (2014) The logic of OSCAR v2.1: C -> RF -> T 7

8 2- Aircraft emissions impact quantification using OSCAR We use OSCAR 2.1 to quantify the impact of airplane emissions: For today, we will focus on CO 2 emissions. We look at: fossil fuel emissions (FF), CO 2 radiative forcing (RF), CO 2 concentration (CO 2 ) and air surface temperature (AST). For each scenario, two simulations are performed: Without CO 2 emissions from planes. With CO 2 emissions from planes. 8

9 2- Aircraft emissions impact quantification using OSCAR Three CO 2 emission scenarios ( ) are used (Sausen and Schumann, 2000 for period and ACARE scenarios for period): - Baseline: Increase of traffic (4.6%/year) + Average fuel efficiency remains at 2010 level - ACARE 1 _optimistic: Increase of traffic + Average fuel eff. of -2.7% kg fuel/km/pass until 2050 then CO 2 emission same as 2050 ( ) - ACARE_pessimistic: Increase of traffic + Average fuel eff. of -2.7% kg fuel/km/pass until 2050 then average fuel eff. stays constant ( ) 1 Advisory Council for Aeronautics Research in Europe The three scenarios are performed using two kinds of RCP (Representative Concentration Pathway) scenarios for the other emissions: - RCP6 (max 6 W/m 2 with a peak of 850 ppm CO 2 eq- with stabilisation shortly after 2100) - RCP85 (max 8.5 W/m 2 with a peak of 1370 ppm CO 2 eq- rising scenario) RCP6 is a stabilization scenario in which total radiative forcing is stabilized shortly after RCP8.5 is a rising scenario (for more detail: van Vuuren et al., 2011 in Climatic Change). 9

10 Mt (CO2) / year Mt (Fuel) / year Global aviation fuel forecast Baseline ACARE Year Global aviation CO2 forecast Baseline ACARE_optimistic ACARE_pessimistic Year 10

11 Fossil Fuel (FF) en GtC For RCP6: FF peak around For RCP8.5: no peak but stabilization starts from Clear difference (from 2050 to 2100) between the optimistic and pessimistic scenario (and for the baseline ). 11

12 3- CO 2 concentration (ppm): The aviation contribution is higher for the baseline (8-10 %) and the pessimistic (around 3-4%) scenarios ACARE_optimistic gives the lowest contribution (<2%). The uncertainty is rather high in 2100 (±100 ppm) but lower in

13 Example of a multi run analysis (Monte Carlo methodology) for CO 2 concentrations used to quantify the uncertainty 13

14 3- Results: Radiative forcing (W/m 2 ): RF (RCP8.5) < RF (RCP6 ) The influence of aviation on RF is low (few %) excepted for the baseline (up to + 10 %). For both RCP, the ACARE_optimistic scenario shows the lowest impact (<2 % increase due to aviation in 2100). For the ACARE_baseline, note the marginal effect of [CO 2 ] on RF from the aviation sector as the RCP goes up (logarithmic relation between [CO 2 ] and RF). 14

15 Surface temperature (K): The influence on AST is low (< 0.1 K) excepted for the baseline (around 0.3 K in 2100 for RCP6). Uncertainty is rather high in 2100 (± 1.5 K). For both RCPs, the ACARE_optimistic scenario shows the lowest impact (< 2% increase due to the aviation in 2050 and a decrease down to 0.8% for the RCP8.5). 15

16 Summary 6 emission scenarios ( ) have been modelled using the SCM OSCAR2.1 AVIATION CONTRIBUTION (%) RCP6 RCP8.5 YEAR VARIABLES PESSIMISTIC OPTIMISTIC PESSIMISTIC OPTIMISTIC FF CO RF Temp FF CO RF Temp The contribution depends on the ACARE scenario and the RCP used. It is maximal for ACARE_pessimistic using the RCP6.0 where the aviation emissions are proportionally higher than in the RCP8.5. In 2050: the contribution from aviation for temperature is 1.4% for RCP6 and 1.0 % for RCP8.5. In 2100: The ACARE_optimistic (in green) is really keeping the aviation contribution close to the 2050 levels compared to ACARE_pessimistic. The uncertainty is rather high in 2100: results have to be interpreted with precaution. According to OSCARv2.1, the ACARE_optimistic scenario will produce the lowest impact. Any other updated/new ACARE scenarios to be taken into account? 16

17 Next steps Same work for NOx (CH 4, O 3 ), BC, sulphates, nitrates. Also working on contrails and associated induced-cirrus. For those species, we use the LMDz-INCA model (gridded or global RF) in interaction with OSCAR2.1 (global T). For 3D modelling, we use the emissions from REACT4C (past) and QUANTIFY (future) projects (any other suggestions?). Compare our results for 2050 to the literature: CO 2 RF = 44 mw/m 2 for ACARE_optimistic and RCP8.5 CO 2 RF = 48 mw/m 2 for ACARE_pessimistic and RCP6 CO 2 RF = 82 mw/m 2 for ACARE_baseline and RCP6 In 2050: CO 2 RF = 75 mw/m 2 Lee et al., AE,

18 Questions? 18