Integrating albedo into integrated assessment

Transcription

1 Integrating albedo into integrated assessment Andrew D Jones, Katherine Calvin, William Collins, Jae Edmonds LBNL - UC Berkeley - PNNL - JGCRI

2 Terrestrial Carbon Management Reforestation & Afforestation Avoided Deforestation Biomass Harvest Biofuels 2 Long Term Sequestration

3 Land Use in Climate Mitigation Policy REDD/ REDD+ (Reduced Emissions from Deforestation and Degradation) Forestry and Ag Offset Programs GHG Inventories Biofuel (or Food) Life Cycle Assessment 3

4 Future Projections of Land Use Differ Widely Lawrence, P. J., J. J. Feddema, G. B. Bonan, G. A. Meehl, B. C. O Neill, S. Levis, D. M. Lawrence, K. W. Oleson, E. Kluzek, K. Lindsay, and P. E. Thornton (2011), Simulating the Biogeochemical and Biogeophysical Impacts of Transient Land Cover Change and Wood Harvest in the Community Source Climate - Bonan System et al. Model AGU (CCSM4) Fall 2010 from 1850 to 2100, Journal of Climate, in review. 4

5 Direct Biophysical Effects of Land Use Change Source - Jackson et al. Environ. Res. Lett.3 (2008)

6 Bonan, G. B. (2008), Forests and Climate Change: Forcings, Feedbacks, and the Climate Benefits of Forests, Science 320, 1444, doi: /science

7 Radiative Forcing (W/m 2 ) Source - IPCC AR4 Synthesis Report 7

8 Only albedo changes are counted in radiative forcing Source - Jackson et al. Environ. Res. Lett.3 (2008)

9 How important is land-use change for future climate? How much and what kind of change will occur? What is the C cycle effect of land-use change? What is the biophysical effect of land-use change? How to understand both regional and global effects? 9

10 What s in store Potential scale of albedo change (iesm) Account for albedo in GCAM Feedbacks when albedo included in targets Implications for assessment 10

11 How does treatment of land use change in policy affect climate? Jones, A. D. et al. (2013), Greenhouse gas policies influence climate via direct effects of land use change, J of Climate, 26(11), , doi: /jcli-d

12 Universal Carbon Tax (UCT) Fossil Fuel and Industrial Carbon Tax (FFICT) 12

13 The Community Earth System Model (CESM) 13

14 The Integrated Earth System Model (iesm) GCAM and GLM Economics Demographics Energy System Ag System 14

15 The Community Land Model Energy Water Carbon and Nitrogen 15

16 (!!" '!!" &!!" %!!" $!!" #!!" Do all RCP4.5 policies lead to same climate? Universal Carbon Tax (UCT)!" $!!!" $!$!" $!&!" $!(!" $!)!" $#!!" Time Two Scenarios: CO2 Concentration (ppm) (!!" '!!" &!!" %!!" $!!" #!!" Fossil Fuel and Industrial Carbon Tax (FFICT)!" $!!!" $!$!" $!&!" $!(!" $!)!" $#!!" Time Identical forcing from greenhouse gases and aerosols 16

17 Do all RCP4.5 policies lead to same climate? Two Scenarios: Universal Carbon Tax (UCT) Fossil Fuel and Industrial Carbon Tax (FFICT) Change in Forest Cover from 2005 to 2100 Very different patterns of land use change 17

18 Global Mean Temp Change Temperature change from first ( ) to last ( ) decade RCP4.5 UCT RCP4.5 FFICT 18

19 Temperature difference FFICT-UCT (decadal mean, ) 50% Forest loss Annual Mean NH Summer NH Winter

20 Surface Albedo difference FFICT-UCT (decadal mean, ) 20

21 Global Mean Temp Change Actually RCP 3.9! Temperature change from first ( ) to last ( ) decade RCP4.5 UCT RCP4.5 FFICT 21

22 The IPCC Parallel Process RCP s Climate Projections SSP s match based on RF Impacts & Adaptation 22

23 A Problem Land-use is not accounted for in the forcing targets used to match RCP s and SSP s Thus, if SSP land-use diverges from the RCP s, their climates no longer match Yet, land-use is an important socioeconomic variable to be explored 23

24 Accounting for land-use forcing within GCAM

25 Forcing is determined by both surface and atmosphere Compare worlds with all woody vegetation and all non-woody vegetation

26 Albedo forcing from removal of woody vegetation

27 Next Step: MODIS surface albedos More landcover types Snow and snow-free conditions

28 Forcing from Land-Use Change Old Model Ref UCT FFICT W/m

29 Why is the forcing smaller? (!"!"#$%!&'()*!+',-(!./!'01!2/1!/-3!,-().'/)!'&!4#5!2/1!667#5!)+-/2(.')!! Forest Cover (M km^2) '!" &!" %!" $!" #!",,-./" ",,-./"678" 9./" " 9./"678"!" $!!!" $!!'" $!#!" $!#'" $!$!" $!$'" $!%!" $!%'" $!&!" $!&'" $!'!" $!''" $!(!" $!('" $!)!" $!)'" $!*!" $!*'" $!+!" $!+'"

30 Why is the forcing smaller? land converted (km^2) latitude

31 Effect of including albedo in policy targets

32 Fossil Fuel Emissions 25 Carbon Price 20 $/tc Ref Ref, w/ Endo Albedo UCT UCT, w/ Endo Albedo FFICT FFICT, w/ Endo Albedo GtC/yr GtC/yr 1 0 Land-Use Change Emissions

33 Forest and Shrub Cover Albedo Forcing million km Ref Ref, w/ Endo Albedo UCT UCT, w/ Endo Albedo FFICT FFICT, w/ Endo Albedo W/m Ref Ref, w/ Endo Albedo million km UCT UCT, w/ Endo Albedo FFICT Bioenergy Crop Area 2 1 FFICT, w/ Endo Albedo

34 Albedo in the SSP s 2095 Land Cover Albedo million km forest shrubs grass pasture biomass W/m SSP1_AFFOREST SSP3_AFFOREST SSP3_DELAY SSP3_REDD SSP3_DEFOREST crops SSP1_AFFOREST SSP3_AFFOREST SSP3_DELAY SSP3_REDD SSP3_DEFOREST

35 Some conclusions Albedo forcing (and climate effect) of land-use change can be quite significant Newer GCAM estimates lower rates of deforestation We can now diagnose albedo change within GCAM even more refined approach is coming Including albedo in forcing targets feeds back onto energy and land-use systems Less deforestation in FFICT despite forcing bonus

36 Should we include albedo effects in policy? Photographer: Roman Makhmutov 36

37 To what extent is land-use forcing equivalent to GHG forcing? Photographer: Roman Makhmutov non-radiative (e.g. hydro) effects spatially concentrated effects 37

38 Have we solved the issue with the parallel process? RCP s Climate Projections SSP s match based on RF Impacts & Adaptation

39 Toward a better assessment process Land-use change and GHG s affect the climate in fundamentally different ways Same is true of aerosols Would we really consider a policy in which we reward aerosol emissions for cooling the planet? Then why do we consider RCP scenarios based on global RF targets? Maybe we should focus on the effect of individual forcings on regions of interest 39

40 Thank You! 40

41 Ideally, forcing is a good proxy for impacts Human Activity Climate Forcing Climate Outcomes Impacts Feedbacks 41

42 Three Simulations Equilibrium response relative to pre-industrial land forcing CO2 forcing net forcing W/m 2 W/m 2 W/m 2 Land Use Change Only Equivalent CO2 Only Land Use Change and Equivalent CO

43 Three Simulations Equilibrium response relative to pre-industrial land forcing CO2 forcing net forcing W/m 2 W/m 2 W/m 2 Land Use Change Only Equivalent CO2 Only Land Use Change and Equivalent CO ppm 43

44 Global Scale Temperature Results 44

45 Land Use Change Cooling Equivalent CO2 Warming Combined Effect With Trading 45

46 Global Scale Temperature Results global temp change % globe affected mean abs change C % C LUC CO2 TRADE

47 Latitudinal Precipitation Response 47

48 Global Scale Precipitation Results global precip change % globe affected mean abs change mm/y % mm/y LUC CO2 TRADE

49 Differential Timing Effects CO2 control LUC 49

50 Forcing additivity does not hold C(fLUC + fco2) C(fLUC) + C(fCO2) 50

51 But, response additvity does seem to hold C(fLUC + fco2) C(fLUC) + C(fCO2) but... C(fLUC, fco2) CLUC(fLUC) + CCO2(fCO2) + 51

52 Temperature Effects Revisited 52

53 Precipitation Effects Revisited 53