What is United States's pathway to limit global warming to 1.5°C?
Current Situation
Emissions profile
The energy sector in the US is by far the largest source of greenhouse gas (GHG) emissions, responsible for more than 80% of total emissions excluding LULUCF. GHG emissions in the US increased significantly during the 1990s before levelling off and peaking in 2007. This trend was largely driven by changes in the energy sector, which was the fastest growing emissions source before peaking in 2005. Since then, energy sector emissions have declined by 15% (as of 2019), largely driven by the availability of cheaper fossil gas and renewables and the subsequent decline in coal consumption in the energy sector.
Within the energy sector, the highest share of emissions comes from the power sector (30%), closely followed by the transport sector (28%). Emissions from the industry and waste sectors have continued to decline since 1990 while agriculture emissions have increased slightly.
United States' current GHG emissions
MtCO₂e/yr
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Graph description
Historical emissions per gas and per sector.
Data References
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Energy system
The US primary energy mix is dominated by fossil fuels, with oil contributing 36% (mostly used in the transport sector), fossil gas 34%, and coal 12% in 2019. Nuclear energy accounts for 10%, while renewable energy makes up about 8% of the energy mix. The pace of renewable energy deployment in the US has lagged behind others such as the European Union, as retiring coal capacity has largely been replaced by fossil gas and regulatory rollbacks have supported fossil fuels.
The share of fossil gas in the power mix has been increasing, and it is largely replacing coal. In 2017, gas and coal had about equal shares in the power mix, but by 2019, the share of gas had increased to 38% while coal decreased to 25%. Nuclear (19%) and renewable energy including biomass (18%) made up the bulk of the remaining generation.
While there are existing policy gaps in the energy sector, President Biden has presented ambitious energy sector reforms including the goal to achieve a “100% clean energy economy” by 2050.1 Biden’s COVID-19 economic recovery plan also includes a target to achieve a “carbon-free power” sector by 2035.2 The Inflation Reduction Act, passed in 2022, is expected to help narrow this gap with significant measures targeting the energy sector such as support for renewable energy and electric vehicles.3
Targets and commitments
Economy-wide targets
Target type
Base year emissions target
NDC target
Market mechanisms
- “At this time, the United States does not intend to use voluntary cooperation using cooperative approaches referred to in Article 6.2 or the mechanism referred to in Article 6.4 in order to achieve its target.”6
Long-term target
- The US long term strategy (LTS) aims to reach net zero emissions by 2050.7 The LTS covers all greenhouse gases and sectors.
Sectoral targets
Energy
Biden climate plan targets:
- “100% clean energy economy” by 2050.8
Power
Biden climate and energy plan targets:
- Carbon-free power sector by 2035.
Transport
Biden climate and energy plan targets:
- Provide all Americans in cities over 100,000 with quality public transport by 2030.
- Upgrade 3 million public fleet vehicles.
- 100% of light/medium duty vehicles electric (no timeline).
- Deploy more than 500,000 new public charging outlets by the end of 2030.
- All new US built buses to have zero emissions by 2030, and to convert all 500,000 school buses to zero-emissions vehicles.
Other targets:
- 50% of new light-duty vehicle sales electric by 2030.9
- 30% of new medium- and heavy-duty vehicle sales to be zero-emission by 2030 and 100% by 2040.10
Buildings
Biden climate and energy plan targets:
- Reduce the carbon footprint of the US building stock by 50% by 2035.
- Net zero emissions standard for all new commercial buildings from 2030.
- Retrofit 4 million commercial buildings and weatherise 2 million homes within 4 years.