United States

Last update: 1 January 2023

Economy wide

To be 1.5°C compatible, the US should aim to reduce emissions by 56-66% below 2005 levels, resulting in an emission level of 2.5-3.3 GtCO₂e/yr by 2030, excluding LULUCF; however, the US is not on track to meet this target.

United States' total GHG emissions excl. LULUCF MtCO₂e/yr

Displayed values

Percent
MtCO₂e/yr

Reference Year

2005
2010
2015

*Net zero emissions excl LULUCF is achieved through deployment of BECCS; other novel CDR is not included in these pathways

Graph description

The figure shows national 1.5°C compatible emissions pathways. This is presented through a set of illustrative pathways and a 1.5°C compatible range for total GHG emissions excl. LULUCF. The 1.5°C compatible range is based on global cost-effective pathways assessed by the IPCC SR1.5, defined by the 5th-50th percentiles of the distributions of such pathways which achieve the LTTG of the Paris Agreement. We consider one primary net-negative emission technology in our analysis (BECCS) due to data availability. Net negative emissions from the land-sector (LULUCF) and novel CDR technologies are not included in this analysis due to data limitations from the assessed models. Furthermore, in the global cost-effective model pathways we analyse, such negative emissions sources are usually underestimated in developed country regions, with current-generation models relying on land sinks in developing countries.

Methodology
- Underlying global pathways
- Downscaling of global pathways
Data References

2030 NDC

In 2021, the US submitted an updated nationally determined contribution (NDC) with a strengthened domestic greenhouse gas (GHG) emission reduction target of 50-52% below 2005 levels by 2030, including land use, land-use change and forestry (LULUCF). This target translates to 3.9-4.2 GtCO₂e/yr by 2030, or 44-47% below 2005 levels, excluding LULUCF.¹^,²

Current policies

The passage of the 2022 Inflation Reduction Act (IRA) is a critical shift in US climate policy. Including the impact of the IRA, US emissions are projected to decline 24-37% below 2005 levels by 2030 excluding LULUCF if no further policies are enacted; however, this does not put the US on track to meet its NDC target.³^,⁴

Fair share

A fair share contribution to reduce global GHG emissions compatible with the Paris Agreement would require the US to go further than its domestic target and provide substantial support for emissions reductions to developing countries. The US’ fair share would require providing support for mitigation abroad equivalent to domestic emissions reductions of at least 75% below 2005 levels by 2030 when excluding LULUCF on top of its domestic reductions.⁵

Long term strategy

The US long term strategy (LTS) aims to reach net zero GHG emissions by 2050 including LULUCF.⁶

2050 Ambition

Excluding LULUCF, our analysis shows that for the US to be 1.5°C compatible, its emissions levels would need to reduce 89-99% below 2005 levels by 2050 to 0.1-0.8 GtCO₂e/yr.⁷^,⁸

Decarbonisation

Achieving net zero CO₂ before mid-century requires rapid decarbonisation in the power sector, as this is a catalyst for decarbonising other sectors. Reductions in the transport and industry sectors would also need to be prioritised as they are significant contributors to US emissions.

Sectors

Power

To align with a 1.5°C compatible pathway, the share of renewable energy in the US power mix would need to grow from 18% in 2019 to 77-93% by 2030, and 96-100% by 2040.
Early decarbonisation of the power sector will be necessary to close the emissions gap in 2030. 1.5°C compatible pathways show a reduction in carbon intensity from around 380 gCO₂/kWh in 2019 to 30-50 gCO₂/kWh by 2030.
Phasing out coal from the power sector by 2029 and gas by 2038-2039, respectively, will enable the required transformation. Considering the long lifetimes and decreasing competitiveness of coal and gas power plants, delaying decarbonisation comes with significant risks of stranded assets to investors, as well as risks to society of locking in high-cost, high-emission technologies.

Buildings

Our analysis indicates that direct CO₂ emissions in the building sector would need to decline by 61 to 73% below 2019 levels by 2030 and reach zero by 2034 to 2049. The transition would be enabled by increased electrification, from about half of the energy use in buildings in 2019 to 70-75% by 2030 and 90 to 92% by mid-century.
The US does not have a national emissions reduction target or strategy for the building sector. However, several states have adopted policies and several federal programmes exist to improve energy efficiency of buildings, and the Inflation Reduction Act (IRA) includes provisions that promote more efficient buildings.⁹

Industry

The US industry sector’s direct CO₂ emissions related to energy demand have declined by nearly 20% since 1990 (as of 2017). Process-related emissions in the sector have also declined since 1990, but at about half the rate of energy-related emissions.
Our analysis indicates that industrial energy-related CO₂ emissions would need to decline by 62-79% by 2030 and reach zero by 2041 to 2047.
The US long-term strategy (LTS) projects a higher emissions pathway for industrial energy-related CO₂ emissions than the analysed 1.5°C pathways, which show these emissions reducing 96% below 2019 levels by 2050. However, these pathways are not a direct comparison, as emissions reductions from CDR technologies are considered separately in the LTS pathways while our assessment includes them.¹⁰

Transport

In 2017, transport was the second biggest emitting sector in the US, accounting for 28% of total emissions excluding LULUCF. The current transport energy mix is dominated by oil with small shares of biomass and fossil gas.
1.5°C pathways analysed here indicate that transport-related CO₂ emissions would need to drop by 44-65% by 2030 compared to 2019 and by 96-98% by 2050, driven by decreasing energy demand, electrification and fuel switching to hydrogen and biofuels.
The Biden administration has announced targets to have half of all new light-duty vehicles and 30% of new medium- and heavy-duty vehicles sold in the US to be zero-emission vehicles by 2030.¹¹^,¹² These targets are supported by the Inflation Reduction Act, which is expected to increase the US EV fleet by 20% above previous projections by 2030.¹³

The United States of America. The United States of America - Nationally Determined Contribution. 2021. ↩
Climate Action Tracker & New Climate Institute. USA | Climate Action Tracker. 2022. ↩
Climate Action Tracker & New Climate Institute. USA | Climate Action Tracker. 2022. ↩
Rep. Yarmuth, J. A. H.R.5376 - Inflation Reduction Act of 2022. (117th Congress, 2022). ↩
Climate Action Tracker. To show climate leadership, US 2030 target should be at least 57-63% - Mar 2021. (2021). ↩
U.S. Department of State. The Long-Term Strategy of the United States: Pathways to Net-Zero Greenhouse Gas Emissions by 2050. 2021. ↩
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. ↩
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). ↩
Rep. Yarmuth, J. A. H.R.5376 - Inflation Reduction Act of 2022. (117th Congress, 2022). ↩
U.S. Department of State. The Long-Term Strategy of the United States: Pathways to Net-Zero Greenhouse Gas Emissions by 2050. 2021. ↩
Shepardson, D. U.S. aims for zero-emissions heavy-duty vehicles by 2040. Reuters. 2022. ↩
The White House. Executive Order on Strengthening American Leadership in Clean Cars and Trucks. The White House. 2021. ↩
Rep. Yarmuth, J. A. H.R.5376 - Inflation Reduction Act of 2022. (117th Congress, 2022). ↩

What is United States's pathway to limit global warming to 1.5°C?