The energy sector in the US is by far the largest source of greenhouse gas emissions, responsible for more than 80% of emissions. Greenhouse gas emissions in the US increased significantly during the 1990s before leveling 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 14% as of 2017, largely driven by the availability of cheaper natural gas and renewables and the subsequent decline in coal consumption in the energy sector.
Within the energy sector, the highest share of emissions come from the power sector (29%), closely followed by the transport sector (28%). Industry and waste emissions have continued to decline since 1990 while agriculture emissions have increased slightly.
9 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.
10 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).
11 When considering historical LULUCF sinks (-765 MtCO₂e on average between 2008-2018), the Mid-Century Strategy projects a level of LULUCF sinks of -409 MtCO₂e by 2050 which would lead to net zero GHGs by 2056.7,8
The United Statesʼ current GHG emissions
MtCO₂e/yr
Displayed values
By sector
Power
Transport
Industry (energy use)
Buildings
Fugitive emissions
Other
Agriculture
Industry (processes)
Waste
LULUCF
By gas
CO₂
CH₄
N₂O
Other
078%0
Sectors by gas
Energy
094%0
Agriculture
00
Industry (processes)
00
Energy system
The US primary energy mix is dominated by fossil fuels, with oil contributing 37% (mostly used in the transport sector), natural gas 30%, and coal 15% in 2017. Nuclear energy accounts for 10%, while renewable energy makes up less than 8%. 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 natural gas and regulatory rollbacks have supported fossil fuels.
Coal and natural gas contributed roughly equal shares to electricity generation, about 31% each in 2017. Nuclear (20%) and renewable energy (17%) made up the bulk of remaining generation.
While there are existing policy gaps in the energy sector, newly elected President Biden has presented ambitious energy sector reforms including the goal to achieve a “100% clean energy economy” by 2050.2 Biden’s COVID-19 economic recovery plan also includes a target to achieve a carbon-free power sector by 2035.2
“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.”4
Long-term target
Biden Plan: net zero by 2050 (proposed). It is however unclear whether it covers GHG emissions (GHG net- zero) or CO₂ emissions only, (CO₂ net- zero) and does not specify whether including or excluding LULUCF.
Sector coverage
EnergyIndustryWasteAgricultureLULUCF
Greenhouse gas coverage
CO₂CH₄NF₃HFCsN₂OSF₆
Sectoral targets
Energy
Biden climate plan targets:
“100% clean energy economy” by 2050.
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.
Power
Biden climate and energy plan targets:
Carbon-free power sector by 2035.
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.