What is United States's pathway to limit global warming to 1.5°C?
Transport
The transport sector’s CO₂ emissions increased rapidly from the early 1990s to the early 2000s before levelling off and dropping following the 2008 financial crisis. Emissions had begun to rebound but dropped again during the COVID-19 pandemic. In 2017, transport emissions were the second largest source of energy-related emissions and accounted for 28% of total emissions excluding LULUCF. The current transport energy mix is dominated by oil with small shares of biomass and fossil gas.
United States' energy mix in the transport sector
petajoule per year
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Graph description
Energy mix composition in the transport sector in consumption (EJ) and shares (%) for the years 2030, 2040 and 2050 based on selected IPCC SR1.5 global least costs pathways.
Methodology
Data References
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1.5°C pathways analysed here indicate that transport CO₂ emissions would need to drop by 44–65% below 2019 levels by 2030, and by 96–98% by 2050. This would be enabled by decreasing energy demand coupled with electrification and fuel switching to hydrogen and biofuels. While the pathways show the US only reaching 5–6% electrification by 2030, this is very likely an underestimation of the potential for electrifying transport in the US.1 Between 2020 and 2021, the EV share of new light-duty vehicles nearly doubled, reaching 4.4% in 2021.
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 2030.2,3 These targets are supported by provisions in the Inflation Reduction Act (IRA) of 2022, such as EV tax credits, installation of charging infrastructure and domestic supply chain development.4 Analysis by BNEF expects IRA provisions to increase the US EV fleet by 20% above previous projections by 2030. California and Massachusetts have set even more ambitious EV targets with other states expected to join.5
Missing from the IRA, however, were significant investments in passenger rail that had been in the failed Build Back Better bill that would help shift the US away from its dependence on cars.6
United States' transport sector direct CO₂ emissions (of energy demand)
MtCO₂/yr
Direct CO₂ emissions only are considered (see power sector for electricity related emissions, hydrogen and heat emissions are not considered here).
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Graph description
Direct CO₂ emissions of the transport sector in selected 1.5°C compatible pathways.
Methodology
Data References
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1.5°C compatible transport sector benchmarks
Direct CO₂ emissions and shares of electricity, biofuels and hydrogen in the transport final energy demand from illustrative 1.5°C pathways for United States
| Indicator |
2019
|
2030
|
2040
|
2050
|
Decarbonised transport sector by
|
|---|---|---|---|---|---|
|
Direct CO₂ emissions
MtCO₂/yr
|
1757
|
619 to
987
|
151 to
162
|
28 to
74
|
2044 to
2054
|
|
Relative to reference year in %
|
-65 to
-44%
|
-91 to
-91%
|
-98 to
-96%
|
| Indicator |
2019
|
2030
|
2040
|
2050
|
|---|---|---|---|---|
|
Share of electricity
per cent
|
0
|
5 to
6
|
25 to
28
|
38 to
59
|
|
Share of biofuels
per cent
|
6
|
21 to
25
|
27 to
52
|
17 to
51
|
|
Share of hydrogen
per cent
|
0
|
1 to
15
|
8 to
50
|
12 to
55
|
All values are rounded. Only direct CO₂ emissions are considered (electricity, hydrogen and heat emissions are not considered here; see power sector for emissions from electricity generation). Year of full decarbonisation is based on carbon intenstiy threshold of 5gCO₂/MJ.
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Methodology
Data References
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