Page 354 Legal Pathways to Deep Decarbonization in the United States
Within the transportation sector, emissions from light-
duty vehicles (LDVs)8 such as cars a nd sport utility vehicles
(SUVs) account for more than one-half of total transpor-
tation GHG em issions.9 As such, LDVs are an important
sector for decarbonization eorts. e Deep Dec arbon-
ization Pathways Project (DDPP) authors anticipate two
changes required for our LDV eet by 2050: (1)increased
fuel economy standards in excess of 100 miles per gallon
(mpg); and (2)deployment of approximately 300 million
alternative fuel vehicles (AF Vs) to shift 80%-95% of the
miles driven from gasoline to low-carbon fuels.10 Relying
upon the 2015 DDPP analysis and its Mixed Scenario,11
which assumes an equa l blend of electric, hybrids, and
hydrogen vehicles, this chapter addresses t hese two spe-
cic challenges and develops legal pathways to achieve
these goals. It begins with a brief primer on LDV types,
their GHG contributions, and the DDPP authors’ projec-
tions for an LDV future (Part I). Part II then describes the
existing legal regime for LDVs and the barriers to achiev-
ing more extensive alternative vehicle deployment. Finally,
Part III advances lega l pathways to achieve the light-duty
decarbonization goals by 2050.
II. The Role of LDVs in Decarbonization
LDVs are the predominant source of GHG and carbon
dioxide emissions in the transportation sector.12 LDVs,
as dened by the U.S. Environmental Protection Agency
(EPA) for emissions purposes, include passenger vehi-
cles such as cars, minivans, light truck s, and SUVs that
8. e EIA denes LDV to
include passenger and eet cars and trucks with a gross vehicle
weight rating (GVWR) of 8,500 pounds or less. Light-duty vehicle
energy consumption can be inuenced by vehicle fuel economy or
through passenger behavior and vehicle use. LDV fuel eciency,
the number of vehicles on the road (vehicle stock and new sales
each year), and the vehicle mix between cars and light-duty trucks
are key factors that determine fuel consumption. Driving behavior,
distance traveled, and driver response to fuel price and vehicle price
also inuence energy consumption by LDVs.
EIA, Light-Duty Vehicles’ Share of Transportation Energy Use Is Projected to
Fall, T E, July 18, 2014, http://www.eia.gov/todayinenergy/
9. T W H, supra note 3, at 41 g. 4.9.
10. J H. W ., P D D
U S, U.S. 2050 R, V 1: T R xiv
(Deep Decarbonization Pathways Project & Energy and Environmental
Economics, Inc., 2015), available at http://usddpp.org/downloads/2014-
technical-report.pdf [hereinafter DDPP T R].
11. e Mixed Scenario also has no deployment of carbon capture and stor-
age (CCS) outside the electricity sector, and a balanced mix of renewable
energy, nuclear power, and natural gas with CCS in electricity generation.
Non-dispatchable renewables and nuclear power are balanced with electric-
ity storage (pumped hydro), exible end-use electric loads (electric vehicles
and thermal loads like water heating), and electric fuel loads. Hydrogen and
synthetic natural gas produced from electricity (referred to as power-to-gas)
and biomass are used to decarbonize pipeline gas, which is used in freight
transport and industry. DDPP T R, supra note 10, at 17,
12. U.S. EPA, Fast Facts on Transportation Greenhouse Gas Emissions, https://
emissions. LDVs emit 60% of total transportation GHG emissions. Id.
have a maximum gross vehicle weight rating of less than
8,500 pound s.13
LDVs are heavily dominated by conventional internal
combustion engines (ICEs) that emit approximately 20
pounds of carbon dioxide for every gal lon of gas burned.14
Other technologies can be used to power these vehicles,
including electric motors and hydrogen fuel cells, but a
number of barriers have limited their development (see
below in Part II). Of the 230 million LDVs on the road in
the United States today, electric and hybrid vehicles repre-
sent well under 1%.15 On an annua l sales basis, EV sa les
still lag far behind ICE sales. For instance, of the 17.55
million passenger vehicles sold in the United States in
2016,16 less than 160,000 of them were EVs.17 is part
will describe four categories of LDVs and their relative
contributions to U.S. GHG emissions.
A. LDV Primer
LDVs can function based on a number of technologies.
e majority of LDVs in the United States have ICEs.18
Alternative types of LDVs include fully battery electric
vehicles (BEVs), hybrid electric vehicles (HEVs), plug-in
hybrid electric vehicles (PHEVs), and hydrogen fuel cell
vehicles (HFCVs) (collectively referred to as “alternative
fuel vehicles,” or “AFVs,” in this chapter).19 Each of these
types wil l be described below, as well as their relat ive GHG
contributions and their role in the DDPP assessment.
13. U.S. Department of Energy (DOE), Alternative Fuels Data Center, Vehicle
Weight Classes & Categories, https://www.afdc.energy.gov/data/widgets/10380
(last visited Feb. 25, 2018).
14. Michael Greenstone, Overlooked Tool to Fight Climate Change: A Tweak
in Fuel Standards, N.Y. T, Mar. 28, 2016, https://www.nytimes.
15. DOE, Oce of Energy Eciency and Renewable Energy, Vehicle Technolo-
gies Oce: Advanced Combustion Engines, http://energy.gov/eere/vehicles/
vehicle-technologies-oce-advanced-combustion-engines (last visited Feb.
25, 2018). In mid-2016, the United States had almost half a million EVs
on the road.
16. Bill Vlasic, Record 2016 for U.S. Auto Industry; Long Road Back May Be at
End, N.Y. T, Jan. 4, 2017, https://www.nytimes.com/2017/01/04/
17. Sunny Trochaniak, Electric Vehicle Sales in the United States: 2016 Final Up-
date, FC, Jan. 19, 2017 (stating that 159,333 EVs were sold in the
United States in 2016), http://www.eetcarma.com/ev-sales-usa-2016-nal/.
18. Advancing Clean Transportation and Vehicle Systems and Technologies, in
Q T. R. 275, 276 (DOE 2015) [hereinafter Advancing
Clean Transportation], https://www.energy.gov/sites/prod/les/2015/09/f26/
19. DDPP T R, supra note 10, at 34. Contrast this with exible
fuel vehicles, which “have an internal combustion engine and are capable
of operating on gasoline and any blend of gasoline and ethanol up to E85
(or ex fuel).” DOE, Alternative Fuels Data Center, Flexible Fuel Vehicles,
https://www.afdc.energy.gov/vehicles/exible_fuel.html (last updated May