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United States Ambition gap

What is The United Statesʼ pathway to limit global warming to 1.5°C?

How to citeLast update: January 2023

1.5°C compatible pathways

Although the US’ updated NDC shows an increase in ambition, now targeting a 50–52% reduction in total GHG emissions below 2005 levels by 2030 including LULUCF (equivalent to 44–47% excluding LULUCF), it is not yet consistent with a 1.5˚C compatible pathway.2 Our analysis indicates that the US would need to increase its new NDC emissions reduction target to 62% below 2005 levels by 2030 to be 1.5˚C compatible (excl. LULUCF).

The country’s current policies (as of August 2022) are insufficient to achieve its updated NDC target; however, the Inflation Reduction Act (IRA) included in the assessment significantly narrowed the gap.3

A fair share contribution to reduce global greenhouse gas emissions compatible with the Paris Agreement would require the US to go further than its domestic target, and provide substantial support to developing countries. The Climate Action Tracker assesses that the US’ fair share (domestic and international support) would require the country to provide support for mitigation abroad equivalent to domestic emissions reductions of at least 75% below 2005 levels by 2030 when excluding LULUCCF on top of its domestic reductions.4

Long term pathway

The US long term strategy (LTS) aims to reach net zero emissions by 2050.5 By mid-century, in a Paris Agreement compatible pathway, GHG emissions should not be higher than 0.1–0.8 GtCO₂e/yr or around 89–99% below 2005 levels excluding land sinks but including the use of BECCS.17

While the energy sector could be fully decarbonised as early as 2038, remaining emissions, mostly from agriculture and waste sectors, will need to be balanced with negative CO₂ emissions through the deployment of carbon dioxide removal (CDR) approaches.

1 The United States of America. The United States of America – Nationally Determined Contribution. 2021.

2 Climate Action Tracker & New Climate Institute. USA | Climate Action Tracker. 2022.

3 Rep. Yarmuth, J. A. H.R.5376 – Inflation Reduction Act of 2022. (117th Congress, 2022).

4 Climate Action Tracker. To show climate leadership, US 2030 target should be at least 57-63% – Mar 2021. (2021).

5 U.S. Department of State. The Long-Term Strategy of the United States: Pathways to Net-Zero Greenhouse Gas Emissions by 2050. 2021.

6 Shepardson, D. U.S. aims for zero-emissions heavy-duty vehicles by 2040. Reuters. 2022.

7 The White House. Executive Order on Strengthening American Leadership in Clean Cars and Trucks. The White House. 2021.

8 Biden for President. The Biden plan to build a modern, sustainable infrastructure and an equitable clean energy future. (2020).

9 Larsen, J. et al. A Turning Point for US Climate Progress: Assessing the Climate and Clean Energy Provisions in the Inflation Reduction Act. 2022.

10 NCSL. State Renewable Portfolio Standards and Goals. NCSL. 2021.

11 Barbose, G. L. U.S. Renewables Portfolio Standards 2021 Status Update: Early Release. 2021.

12 Denholm, P. et al. Examining Supply-Side Options to Achieve 100% Clean Electricity by 2035. 2022.

13 ICAP. Welcome to the ICAP ETS Map. International Carbon Action Partnership. 2022.

14 Cui, H. & Hall, D. Annual update on the global transition to electric vehicles: 2021. ICCT. Preprint at (2022).

15 E360. U.S. Inflation Reduction Act to Boost EV Adoption by 20 Percent, Analysis Finds. Yale Environment 360. 2022.

16 Wilson, K. Advocates: Cutting High Speed Rail Out of Climate Bill Was a Mistake. Streetsblog USA. 2022.

17 While global cost-effective pathways assessed by the IPCC Special Report 1.5°C provide useful guidance for an upper-limit of emissions trajectories for developed countries, they underestimate the feasible space for such countries to reach net zero earlier. The current generation of models tend to depend strongly on land-use sinks outside of currently developed countries and include fossil fuel use well beyond the time at which these could be phased out, compared to what is understood from bottom-up approaches. The scientific teams which provide these global pathways constantly improve the technologies represented in their models – and novel CDR technologies are now being included in new studies focused on deep mitigation scenarios meeting the Paris Agreement. A wide assessment database of these new scenarios is not yet available; thus, we rely on available scenarios which focus particularly on BECCS as a net-negative emission technology. Accordingly, we do not yet consider land-sector emissions (LULUCF) and other CDR approaches which developed countries will need to implement in order to counterbalance their remaining emissions and reach net zero GHG are not considered here due to data availability.

18 In some of the analysed pathways, the energy sector assumes already a certain amount of carbon dioxide removal technologies, in this case bioenergy carbon capture and storage (BECCS).


The United Statesʼ total GHG emissions

excl. LULUCF MtCO₂e/yr

Displayed values
Reference year
Reference year
1.5°C emissions level
Ambition gap
  • 1.5°C compatible pathways
  • Middle of the 1.5°C compatible range
  • Current policy projections
  • 1.5°C emissions range
  • Historical emissions
2030 emissions levels
Current policy projections
1.5°C emissions level
Ref. year 2005
7 435MtCO₂e/yr

Energy system transformation

The required CO₂ emissions cuts would need to come mainly from the decarbonisation of the country’s energy mix. Across most analysed pathways, this requires absolute fossil fuel consumption to be more than halved by 2030 from more than 80% of the primary energy mix in 2019. To support this decarbonisation pathway, renewable energy needs to increase from 8% of the total primary energy mix in 2019 to 21-46% by 2030. Some models show a penetration of negative CO₂ emissions technologies such as BECCS by 2030, implying that the country may need to plan their development in the next few years.


The United Statesʼ primary energy mix

petajoule per year

SSP1 Low CDR reliance
201920302040205040 00060 00080 000
SSP1 High CDR reliance
201920302040205040 00060 00080 000
Low energy demand
201920302040205040 00060 00080 000
High energy demand - Low CDR reliance
201920302040205040 00060 00080 000
  • Negative emissions technologies via BECCS
  • Unabated fossil
  • Nuclear and/or fossil with CCS
  • Renewables incl. biomass

The United Statesʼ total CO₂ emissions

excl. LULUCF MtCO₂/yr

−2 00002 0004 0006 00019902010203020502070
  • 1.5°C compatible pathways
  • 1.5°C emissions range
  • Middle of the 1.5°C compatible range
  • Historical emissions

1.5°C compatible emissions benchmarks

Key emissions benchmarks of Paris compatible Pathways for The United States. The 1.5°C compatible range is based on the Paris Agreement compatible pathways from the IPCC SR1.5 filtered with sustainability criteria. The median (50th percentile) to 5th percentile and middle of the range are provided here. Relative reductions are provided based on the reference year.

Reference year
Reference year
Year of net zero
incl. BECCS excl. LULUCF and novel CDR
Total GHG
Megatonnes CO₂ equivalent per year
7 435
6 572
2 844
2 518 to 3 280
1 225
721 to 1 656
101 to 813
Relative to reference year in %
−66 to −56%
−90 to −78%
−99 to −89%
Total CO₂
6 149
5 279
2 386
1 747 to 2 648
105 to 1 215
−278 to 382
2043 to 2063
Relative to reference year in %
−72 to −57%
−98 to −80%
−105 to −94%