U.S. Emissions to 2050
Jae Edmonds
29th Asia Integrated Modeling Meeting
14 September 2023
I am grateful to colleagues Michael Westphal (PNNL) and Ryna Cui (UMD) for their assistance in preparing this presentation
DRAFT PRESENTATION—COMMENTS WELCOME

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United States National Climate Policy• The United States has committed to reducegreenhouse gas emissions by 50 to 52 percent in 2030.
• Reaching 100% carbon pollution-free electricity by2035.
DRAFT PRESENTATION—DO
NOT QUOTE, SUBJECT TO CHANGE• And, Net Zero greenhouse gas emissions in 2050.
• Bipartisan Infrastructure Law (passed November 2021)• Inflation Reduction Act (August, 2022)
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The Inflation Reduction Act (IRA) was passed in August of 2022.
U.S. It is NOT a simple carbon tax! It is a challenge to model!

DRAFT PRESENTATION—DO NOT QUOTE, SUBJECT TO CHANGE

DRAFT PRESENTATION—DO NOT QUOTE, SUBJECT TO CHANGE

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Assessing how the U.S. climate targets can be achieved requires insight into
its multi-tiered governance structure and an all-of-society approach• We have observed higher ambition from nonfederal actors (states, cities, businesses, etc.) indiverse contexts.
• Integrating all actions enables a more robust
strategy to deliver emissions reductions and provide
options to go further and faster.

Examples of policies driven from the bottom up:•GHG vehicle emission standards by California
and ten other states helped set ambition forfederal standards in 2009•

State renewable standards, public and private
renewable procurement targets, and civil society
pressure for coal plant retirements have driven
power sector emission reductions•

State HFC phase-down policies led tocorporate support for federal action, adopted
under the AIM Act of 2020

Slide Courtesy of Ryna Cui4

How do we fill the gap with continued actions from both federal andsubnational levels? All-of-society strategy
Research Approach and Methodological Toolkit:
Collaborative Policy Platform Development + Scenario
Construction + Emissions and Energy Transition Assessment via
a Global Integrated Assessment Model (GCAM-USA-CGS)
GCAM-USA

Hultman et al. 2020. “Fusing national and sub-national climate action is central to rapid near-term decarbonization: The case of the United States.”Nature Communications. 11: 5255
Hultman et al. 2019. “Accelerating America’s Pledge.” The America’s Pledge Initiative on Climate Change and Bloomberg Philanthropies, with theUniversity of Maryland Center for Global Sustainability, Rocky Mountain Institute, and World Resources Institute.
Kennedy et al. 2021. “Blueprint 2030.” America Is All In.
Zhao et al. 2022. “Transportation Sector Emissions Reduction Potential.” America Is All In.
Zhao et al. 2022. “U.S. Methane Emissions Reduction Potential.” America Is All In.
Zhao et al. 2022. “An All-In Pathway To 2030: The Beyond 50 Scenario.” CGS-UMD and America Is All In. 16 pp.

5Impact of the IRA and BIL
DRAFT PRESENTATION—DO NOT QUOTE,
SUBJECT TO CHANGE

Emissions reductions under Existing Policies and Beyond 50scenarios
The existing policies
scenario can achieve 39%
reductions by 2030 from2005 levels with potential for
42% reductions withaccelerated implementation.
The Beyond 50 scenario
uses an all-of-society,accelerated approach to anational climate strategy andshows a pathway for theUnited States to achieve 52%
emissions reductions from2005 levels by 2030.

Zhao et al. 2022. “An All-In Pathway To 2030:
The Beyond 50 Scenario.” CGS-UMD andAmerica Is All In. 16 pp.

U.S. Primary Energy Mix: Impact of IRA+BIL
U.S. Primary Energy
No IRA

890908080

67070

4606050404030302020101002015

2020

2025

2030

2035

2040

2045

Slide Courtesy of Michael Westphal

2050

20

EJ/year

50

Contribution of the IRA(IRA less no-IRA)

IRA

100

EJ/yearEJ/year100

0-2-4-6

2015

2020

2025

2030

2035

2040

2045

2050

-8

2015

2020

2025

2030

2035

2040

2045

2050

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GCAM Analysis of the IRA and BIL: U.S. Primary Energy Mix
U.S. Primary Energy

IRA+BIL with assumedexpiration
Slide Courtesy of Michael Westphal

IRA+BIL with extensions toachieve the U.S. Net Zero 2050
Goal

2021 Long-term StrategyAnalysis—Carbon Tax to achieve
U.S. Net Zero Goal

9U.S. Primary Energy Mix: IRA Alone to IRA+Net Zero Measures
U.S. Primary Energy
IRA

IRA to NZ

100

90

90

80

80

70

70

60

60

50

40
30
20
1050

0

40

40

30

30

20

20-30

1010-4002015

2020

2025

2030

2035

2040

2045

Slide Courtesy of Michael Westphal

2050

0Contribution of the IRA-NZ(IRA less no-IRA)

50

EJ/yearEJ/yearEJ/year100-10-202015

2020

2025

2030

2035

2040

2045

2050-502015

2020

2025

2030

2035

2040

2045

2050

10

U.S. Primary Energy Mix: IRA to Net Zero Compared to LTS
U.S. Primary Energy
100

9090

80

80

7070

60

60
EJ/yearEJ/year

100

50

40

30

30

202010102015

2020

2025

2030

2035

2040

2045

Slide Courtesy of Michael Westphal

2050

150

Comparison IRA to NZ and LTS

10

550

40

0

2021 U.S. Long-term Strategy

EJ/year

IRA to NZ

0-5-10

2015

2020

2025

2030

2035

2040

2045

2050-15

2015

2020

2025

2030

2035

2040

2045

2050

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GCAM Analysis of the IRA and BIL: U.S. Power Sector
Electricity Generation

CurrPol(IRA +BIL)

CurrPol-NZ

U.S. Long-term
Strategy (LTS)

Slide Courtesy of Michael Westphal

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GCAM Analysis of the IRA and BIL: U.S. CO2 Emissions

IRA +BIL with assumed
expiration
Slide Courtesy of Michael Westphal

IRA +BIL with extensions toachieve the U.S. Net Zero 2050
Goal

2021 Long-term StrategyAnalysis—Carbon Tax to achieve
U.S. Net Zero Goal

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Concluding Thoughts• Modeling the IRA and BIL is a challenge.
• Modeling the full spectrum of U.S. policies across the entire fabric ofsociety is an even bigger challenge.

GCAM Analysis• The IRA and BIL reduce U.S. GHG emissions by 2030, but not enoughto reach the U.S. 50-52% GHG reduction relative to 2005 goal.
• There are post-2030 emissions mitigation resulting from the IRA evenafter it expires.
• Additional measures are required to meet the U.S. 2030 and 2050
goals.
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