edit Master title style Click to edit Master title style Click ... - DSpace@MIT

Click to edit Master title style Click to edit Master title style • Climate Click to Change edit Master styles Emissions: andtext Methane • Click to edit Master text styles • Using Second level Analysis Tools to Advise Policy Integrated • Second level • Third level • Third level • Fourth level Marcus C. Sarofim • Fourth level • Fifth level • Fifth level

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Click to edit Overview Master title style Click to edit Master title style • Climate Change Background Click to edit Master text styles • –Click to edit Master text styles The Science • Second level –Second The Politics • level • Third level • •The Role of Methane Third level • Fourth level Wisdom – Conventional • Fourth level • Fifth level results (political, economic, and – Research • Fifth level scientific) – Policy recommendation: decouple CO2 from CH4 policy 2 2

The Earth’s Balance Click to editRadiative Master title style Click to edit Master title style • • • • •

107

Reflected Solar Radiation 107 Wm-2 Reflected by Clouds, and Atmosphere

Outgoing Longwave Radiation 235 Wm-2

235

Incoming Solar Radiation 342 Wm-2

342

40

77 Emitted by Atmosphere 165

77

30

Atmospheric Window Greenhouse Gases

Absorbed by 67 Atmosphere 24

Reflected by Surface 30 30

Latent 78 Heat 350

168 Absorbed by Surface

24 Thermals

390 78 Surface EvapoRadiation transpiration

40

324 Back Radiation 324

Absorbed by Surface

Figure by MIT OCW, based on Kiehl and Trenberth 1997.

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Radiative Forcing Components -2

RF values (Wm )

Spatial scale

LOSU

1.66 [1.49 to 1.83]

Global

High

0.48 [0.43 to 0.53] 0.16 [0.14 to 0.18] 0.34 [0.31 to 0.37]

Global

High

0.35 [0.25 to 0.65]

Continental to global

Med

0.07 [0.02 to 0.12]

Global

Low

-0.2 [-0.4 to 0.0] 0.1 [0.0 to 0.2]

Local to Continental

Med - Low

Direct effect

-0.5 [-0.9 to -0.1]

Continental to global

Med - Low

Cloud albedo effect

-0.7 [-1.8 to -0.3]

Continental to global

Low

Linear contrails

0.01 [0.003 to 0.03]

Continental

Low

Solar irradiance

0.12 [0.06 to 0.30]

Global

Low

RF Terms

Long-lived greenhouse gases

{

CO2 N2O

Anthropogenic

Ozone

Stratospheric

-0.05 [-0.15 to 0.05]

Tropospheric

Stratospheric water Vapour from CH4 Land use

Surface albedo

Total Aerosol

Natural

Halocarbons

CH4

{

Black carbon on snow

Total net anthropogenic

1.6 [0.6 to 2.4]

-2

-1 0 1 -2 Radiative Forcing Wm

Figure by MIT OCW, based on IPCC.

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Click to editPolitics Master title style Click to edit Master title style • Click UN Framework Convention on Climate Change to edit Master text styles

• –Click to editof Master text styles Stabilization Greenhouse Gases at a level avoiding • Second level dangerous anthropogenic interference • Second level • Third level commitment – No binding ThirdProtocol level • •Fourth Kyoto level • –Fourth level “Annex B” nations have commitments in 2008-2012 • Fifth level Multiple gases: CO2, CH4, N2O, HFCs, PFCs, SF6 • –Fifth level • Cap and trade: using Global Warming Potentials

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Global Potentials ClickWarming to edit Master title(GWPs) style

Click to edit Master title style IPCC TAR

20 year

100 year

500 year

• Click to edit Master text styles • Click to edit1Master 1text styles CO 1 • Second level 2 • Second level CH4 62 23 7 • Third level N2O 296 156 • Third level 275 • Fourth level • Fourth level • Fifth level a x * [ x(t )]dt ∫ • Fifth level GWP( x) =

∫a

CO2

IPCC 1996 (100 year) 1 21 310

* [CO2 (t )]dt

EPPA, Kyoto, and US inventories all use IPCC 1996 100 year GWPs 6 6

Anthropogenic Emissions Click to edit Master title style GWP weight Click toby edit Master title style • Click to edit Master text styles GHG emissions, 2000 • Click to edit Master text styles • Second level Total: 10.3 GtC eq. • Second level • Third level • Third level N2O • Fourth level • Fourth level CH4 • Fifth level • Fifth level CO2

(emissions data from the MIT EPPA model)

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Methane: Click to edit Master title style Arguments GWP based Trading Click toagainst edit Master title style • Click Conventional to edit Wisdom Master text styles

• –Click to“What” edit Master styles Capture flexibility text by trading among GHGs • Second level • •Results of this study Second level • Third level – CO2 constraints have negative interactions with • Third level economic distortions • Fourth level • –Fourth Methanelevel is undervalued for reasons of chemistry and • Fifth level timing • Fifth level

– Methane emission inventories are much less accurate than fossil CO2 emission inventories – Methane constraints are politically more palatable to developing nations 8 8

The MIT Integrated Global Click to edit Master title style Model Click toSystems edit Master title style • Click to edit Master text styles • Click to edit Master text styles • Second level • Second level • Third level • Third level • Fourth level • Fourth level • Fifth level • Fifth level

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Anthropogenic Methane Sources Click to edit Master title style

Click to edit Master title style Biological Sources: Other (Combustion, w astew ater)

• Anaerobic Click to edit Master text styles decomposition • Click Fossil Sources to edit Master text styles • Second level Total: 300 to 400 Tg/year (2 to 3 GtCeq) • Second level • Third level • Third level • Fourth level Data Source: US EPA bottom-up inventory • Fourth level Exploded slices indicate methane capture • Fifth level potential • Fifth level Manure

Agriculture (rice, livestock)

Landfills

Oil

Coal Gas

CO2 Sources: Fossil Fuels: 7 GtC/yr

(85% of energy in 2000 is from fossil fuels)

Cement: 0.3 GtC/yr Land-Use Change: 0.5 – 2.7 GtC/year

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Global (2010) ClickMarginal to editAbatement Master Curves title style

Click to edit Master title style 1) Many low cost methane

Carbon Equivalent Price (1997$/ton)

100

90 80 70

abatement opportunities are • Click to edit Master text styles available (Kyoto Protocol in 2010 • Click to edit Master text stylesthe US would have even including • Second level required ~ 500 MMT carbon • Second level equivalent reduction) • Third level • Third level • Fourth level 2) Because of CO constraint • Fourth level interactions with tax distortions, • Fifth level GWP based inter-gas trading leads to non-optimal solutions • Fifth level 60 50 40

CO2

30

CH4

20 10

0

0

100

200

300

400

500

600

700

800

Carbon Equivalent Reduction (MMT)

Marginal consumption loss (1997$/ton)

100

90

2

80 70 60 50

CO2

40 30

CH4

20 10 0 0

100

200

300

400

500

600

CE Reduction (MMT) (single gas)

700

800

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Non-CO2 gas reductions: Click to edit Master title style Impacts on climate Click to edit Master title style • Click to edit Master text styles CO2ONLY scenario: CO2 • Click to edit Master text styles emissions from 550 ppm • Second level scenario, all other gases as • Second level • Third level reference • Third level Other Gases scenario: CO2 • Fourth level emissions from reference, all • Fourth level other gases from 550 ppm • Fifth level scenario • Fifth level 4

T Change Since 2000 (°C)

3.5 3

2.5

Other Gases

Reference

2

CO2ONLY

1.5 1

550 ppm

0.5 0

2000

2020

2040

2060

2080

2100

Year

US Climate Change Science Program Level 2 scenario: 550 ppm CO2 stabilization, separate emissions paths for other Kyoto gases (CH4, N2O, HFCs, PFCs, SF6), meeting an overall radiative forcing target 12 12 12

Climate of CH4title reduction Click toImpacts edit Master style

Click to edit Master title style

Results in 2100

Constraining CH4 emissions to be constant at 2005 levels

A GWP equivalent scenario, constraining CO2 only

• Click to edit Master text styles • Click to edit Master text styles • reduction Second level % in T rise 14.9% 4.0% • Second level Global ozone conc. (ppb) 36.8 40.1 • Third level CH• lifetime (years) 9.0 10.8 Third level • Fourth level • Methane Fourth level alone can reduce temperature rise by 15% over • reductions • Fifth level century • theFifth level 4

•

100 year Global Warming Potentials seriously undervalue CH4 for century scale temperature reduction

– –

Chemistry: ozone and lifetime feedbacks Emission timing effects 13 13 13

Methane Chemistry Click to edit CHMaster title style 8O + hv -> Net: CH +style Click to edit Master title OH · 4

4

2

CO2 + 4O3 + 2H2O

HO2· + NO -> NO2 + OH·

• Click to edit Master CH text · + H Ostyles • Click to edit MasterOtext stylesNO • Second level NO • Second level CH3O · HO · • Third level • Third level OH · • Fourth level CH O · CH OOH Deposition • Fourth level • Fifth level O • Fifth level OH · HCHO 3

2

2

2

2

2

3

3

2

NO2

OH · or hv NO2 + hv -> NO + O O + O2 -> O3

CO + (H2, HO2 ·,H2O) OH ·, O2 CO2 + HO2·

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Methane Inventories: Bottom up EQUATION 10.19 ENTERIC FERMENTATION EMISSIONS FROM A LIVESTOCK CATEGORY Emissions = EF(T)

] ] N(T) 10

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Where: Emissions = methane emissions from Enteric Fermentation, Gg CH4 yr-1

-1

EF(T) = emission factor for the defined livestock population, Kg CH4 head yr-1 N(T) = the number of head of livestock species/category T in the country T = species/category of livestock

EQUATION 5.1 CH4 EMISSIONS FROM RICE CULTIVATION CH4 Rice =

∑ (EFi.j.k

ti.j.k

Ai.j.k

-6

10 )

i.j.k

Where: CH4 Rice = annual methane emissions from rice cultivation, Gg CH4 yr-1 -1

EFijk = a daily emission factor for i, j, and k conditions, Kg CH4 ha day-1 tijk = cultivation period of rice for i, j, and k conditions, day Aijk = annual harvested area of rice for i, j, and k conditions, ha yr-1 i, j, and k = represent different ecosystems, water regimes, type and amount of organic amendments, and other conditions under which CH4 emissions from rice may vary

Image by MIT OCW.

Methane Inventories: Inverse Click to edit Master titleModeling style

Click to edit Master title style

• Click 92 Methane to edit Master monitoring text sites styles • Click to edit Master text styles • Second Observed winds level • Second level Third level model • Chemistry • Third level Fourth level • Estimates of OH sink • Fourth level • Fifth level • Fifth level

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Inventories ClickMethane to edit Master title style Inverse title style Bottom-up Anthro.Master Click to edit IPCC Guidelines for GHG Modeling methodologies CH inventories are based on bottom-up approaches.

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Results emissions • Click to edit Master text styles in 2000 Chen & Prinn EPA • Click to edit Master text styles(2006) (2006) • Second level 112 30 Rice But • if bottom-up inventories Second level • inaccurate, Third level are their use in Biomass 48 22 trading regimes is • Third level burning questionable • Fourth level Animals + 185 156 • Fourth level waste • Fifth level Contrast: Fossil CO 48 75 • Fifth level Energy 2

Similar Problems: N2O, land use change CO2

EDGAR 32FT2000 39 22 147 94

Other

37

3

19

Total

430

287

321

Therefore: until methodology is improved, regulatory methods other than economic instruments (tax, cap & trade) should be used for methane control.

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Click to Political edit Master Analysis title style Click to edit Master title style •• Click Kyoto Protocol to edit

Master text styles All Gases: CO2, N2O, industrial gases by 100 year GWPs • ––Click to edit Master text styles Limited Nations: • Second level EU, Japan, NZ, Canada, Russia • ~20% of global CH emissions • Second level • CDM extension to non-Annex B • Third level • •Methane to Markets Initiative Third level • Fourth level – Methane only • –Fourth level Non-Kyoto participants: US, China, India, Brazil, Mexico, and • Fifth level Australia • Fifth level • M2M nations emit ~60% of global CH 4

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– Drawbacks • “Voluntary”, “non-binding”: depends on “public-private partnerships” • Target is only 50 MMT Carbon equivalent reduction

• Evidence of OECD historical CH4 reductions 18 18 18

ClickDifferent to edit Master Strategies? title style Click to edit Master title style •

Methane

• Click edit Master text styles – Short to lifetime Cheap abatement • –Click to edit Master text styles • Second level – Most emissions are hard to quantify –Second Recommend level • • Command • Third leveland Control instruments like best practices • Near term implementation • Third level •• Carbon Dioxide Fourth level Long lifetime • ––Fourth level Long term zero emission target • Fifth level – Capital intensive • –Fifth level are well quantified Fossil emissions – Recommend • Near term price signals • Long term research initiatives

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Click to edit Cautions Master title style Click to edit Master title style • Click Possible to edit delay Master of CO text styles 2 abatement • Click to edit Master text styles • Second Potentiallevel increased policy complexity • Second level Third of level • Loss “what” flexibility • Third level • Fourth level • Fourth level • Fifth level • Fifth level

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Click to edit Conclusions Master title style Click to edit Master title style • Click PolicytoAdvice edit Master text styles • –Click to edit Masterpolicy text and styles Uncouple methane CO2 policy • Second level • Second level – Implement • Third level methane policies immediately • Using a mix of policy instruments • Third level • Fourth level Use a different • –Fourth level strategy for CO2 • Fifth level • •Methodology Fifth level – Importance of integrated approach: science, economics, and policy evaluated together 21 21 21