December 18, 2020

Environmental, Natural Resources, & Energy Law Blog

Car emissions are a major source of pollution - Justin Avellar

Car emissions are a major source of pollution. Cars and trucks emit twenty percent of all greenhouse gases emitted in the United States[1], which is the second largest greenhouse gas emitter in the world.[2] It was the largest for decades. This puts vehicle emissions in the United States as one of the largest greenhouse gas emitters in the world.

That is a problem. The United States is dependent on vehicle travel for everything—commuting, shopping, travelling, and more. American cities and suburban areas are structured around the car. This is changing,[3] but it will not change overnight. And it will not change for everyone. Many people will remain in suburban areas that require cars for part of their daily lives. Part of that will be by choice, while for others it will be out of necessity. Not everyone can afford to live by a great mass-transportation line, or a bike path. And people who work in more rural areas will not have easy access to any transportation.

Vehicles are here to stay. They might not remain the dominant form of transportation in all areas of the United States, as cities are reshaped, but they will remain useful and vital to many people in many areas.

We need to do something. Global warming is having immediate, intense, and increasingly severe consequences on both the non-human and human environments.[4] Reducing car emissions quickly would provide sizeable impacts because the amount people drive. And it would allow people to feel they are making a difference in reducing their impact on the climate—to help avoid people nihilistically giving up on making change.

Electrification is key. The technology is readily available, scalable, increasingly affordable, and far more efficient than traditional internal combustion engines. The old concerns about using electric vehicles—they are slow, do not charge quickly, lack good range, and are overly expensive—have become outdated falsehoods.

It is time to force the switch. The current automobile market is not electrifying fast enough. Legacy internal combustion engine automakers have been dragging their feet for decades. And the United States federal government has not provided sufficient pushback to make change. State and local governments can be the changemakers through limiting the sale and usage of internal combustion engine vehicles while promoting electric vehicles. And they could successfully avoid federal preemption or the commerce clause.

This article is broken into two parts. First, it will discuss the problem of global warming and the impact of vehicle pollution at greater length. Second, it will discuss potential solutions states can implement.

The Problem

Global warming is a catastrophe with its consequences unfolding and magnifying right now. The Natural Resources Defense Council (“NRDC”) has written that “Over the past 50 years, the average global temperature has increased at the fastest rate in recorded history. And experts see the trend is accelerating.”[5] This is causing a magnitude of negative impacts on the environment, including heat waves, droughts, heavier rainfall, and hurricanes of increased severity.[6] On the West Coast, impacts also include more severe and longer fire seasons.[7]

This is caused by human activity. Greenhouse gases, such as carbon dioxide and methane, are released through human activity in large-enough amounts to increase the greenhouse effect.[8]

Cars are a massive contributor to greenhouse gas emissions. Every gallon of gas used by a car emits about 24 pounds of greenhouse gasses.[9] Nineteen pounds come from the car’s burning of the fuel in its internal combustion engine, while the remainder come from getting the gas out of the ground and to the fuel pump.[10]

Limiting New Internal Combustion Engine Car Sales

It would be naïve to suggest there is “one” or “the” solution to global warming. That would risk oversimplifying an extremely complex problem and ignoring many possible solutions and peoples’ voices. There are drawbacks to every possible change. They have to be considered and weighed against the risk of inaction. But inaction is not a solution.

One possible solution is banning sales of new internal combustion engine vehicles. California has led the way here. After a terrible fire season this year, Governor Gavin Newsom signed an executive order requiring the state to implement regulations ending the sale of new internal combustion vehicles by 2035 in the state.[11]

This would lead to a dramatic reduction in greenhouse gas emissions from vehicles—even before 2035. Car manufacturers have to develop new cars years ahead of their release. And selling millions more electric cars would require implementing new infrastructure to accommodate all the cars requiring fast charging on highways and in parking lots. If this rule is fully implemented, automakers and related companies will begin producing more vehicles and charging infrastructure well before the 2035 deadline. Those that do not will be left behind in the United States’ largest car market. Therefore, although new internal combustion vehicles can still be sold in the state for 15 years, they will quickly take a backseat to electric vehicles.

However, the implementing regulations drafted by the California Air Resources Board will be heavily litigated. If California does not receive a waiver under the Clean Air Act,[12] opponents to the internal combustion engine ban will argue California’s new regulation is expressly preempted by the Clean Air Act.

If this path is blocked by an increasingly conservative federal judiciary, states can pursue a carrot and stick approach to zero emission vehicles. This could involve taxing internal combustion engine vehicle purchasers at the time of purchase and taxing fuel. The initial purchase tax could serve as a subsidy to help people purchase zero-emission vehicles. The subsidy could be provided to zero emission vehicle purchasers based on income. Then, the fuel tax could go towards adaptations needed by the state for climate change.

Limiting Internal Combustion Engine Car Rentals

A second possible solution is to prevent rental car companies from renting internal combustion vehicles in a particular state. This would work well in conjunction with the new internal combustion vehicle sale ban. It would prevent a large car buyer from importing new internal combustion vehicles they purchased in other states. It would also reduce greenhouse gas emissions because car rental companies have large fleets of vehicles. Forcing these to become electrified would reduce those emissions. Simultaneously, it would create reliable demand for electric vehicles from large buyers. This would improve the predictability of the electric vehicle market for automakers.

This could be accomplished in two ways. First, it could be accomplished through a ban of rental car companies renting internal combustion engine vehicles. This would probably be met with vigorous litigation by rental car companies. They could claim this violates preemption of greenhouse gas regulation from cars under the Clean Air Act. They might also claim it is a violation of the dormant commerce clause. These would be nuanced and difficult claims to litigate. States would have to factor in litigation expense and litigation risk.

Instead, it could be easier, and more profitable, to implement a tax regime for rental cars. The state could tax a rental car at miles driven times the social cost of carbon. The state could also calculate into its social cost of carbon metric the specific measures it will have to take to adapt to a changed environment. For example, Oregon, Washington, and California would include the cost of wildfire management. This would make renting larger internal combustion engine vehicles more expensive than more efficient vehicles.

This is a way to push rental car companies to purchase fleets of zero-emission vehicles. Unlike individual consumers, rental car companies purchase large amounts of vehicles simultaneously. Changing their buying behavior would have outsized impacts on the zero-emission vehicle market.

Pushing rental car companies to use zero emission vehicles would also impact the second-hand car market. Many car rental companies purchase the cars form car manufacturers and sell them as used vehicles after a few years.[13] This would help flood the used car market with electric vehicles. More used electric cars would depress their resale price. That would make them more affordable to people who would not otherwise have the finances to afford an electric vehicle. Furthermore, it would dramatically harm the price of used internal combustion engine vehicles. Price-focused buyers would not have to purchase an internal combustion engine vehicle because they could now afford an electric one.

Subsidies for new zero-emission vehicles would also impact the price of used zero-emission vehicles. It would ensure the used cars are selling for a decent percentage below the new car’s subsidized price. This could make used cars less valuable. But that might not be a bad thing. It could force rental car companies to utilize the vehicles for longer periods of time—which would decrease wasteful car buying.

Similarly, states and municipalities could implement a gas tax at the social cost of carbon. Any money raised through these taxes could go into subsidies to reduce the purchase price of zero-emission vehicles and implementing infrastructure for zero-emission vehicles. This would impact the behavior of car owners and renters. But any gas tax would be unpopular unless those impacted were subsidized sufficiently to mitigate major impacts.

Adapting Streets to Favor Zero Emission Vehicles

In addition to sale and rental requirements, states and cities can continue prioritizing electric vehicles on the roads. This will make it easier for zero emissions vehicles to drive in certain areas while discouraging internal combustion engine car owners from using their cars as much.

Municipalities can implement streets or zones where non zero emission vehicles have to pay a toll.[14] London, for example, implemented a low emission zone in 2008. It “specifies emission requirements for heavy vehicles driven in the city” and has been strengthened gradually.[15] It now has an ultra-low emission zone in the congestion zone to help address nitrogen dioxide pollution. It includes taxis and for-hire vehicles—which has incentivized those fleets to become less polluting.[16]

This can help combat the built-in advantage internal combustion engine vehicles have. It will force people out of their vehicles into transit or to adopt zero emission vehicles. Those that decide to pay the toll will subsidize the development of more transportation options and zero emissions vehicle adoption.

In addition, they can implement zero-emission vehicle lanes. Oslo provides access to bus and taxi lanes for zero emission vehicles.[17]

Or they can raise tolls for internal combustion vehicles on bridges or other roadways, but not for electric vehicles. Oslo provides free passes on toll roads and free travel on ferries.[18]

Municipalities and states should increase charging locations. They can do so through bond raises, taxes, or zoning requirements. For example, local governments could require new commercial construction to include level two chargers for a certain percentage of the building’s parking. It makes zero emission vehicles more viable, informs the public the technology is ready for adoption, and reduces range anxiety.[19]



Global warming is a pressing, immediate problem, with no single, straightforward solution. A lot has to change to make meaningful emissions reductions to stop even-worse impacts. Changing Americans’ cars is an important change. But it is a complex road. In addition to any roadblocks presented by legacy, vested interests, governments and individuals and companies have to heavily invest in a wide array of technologies and incentives to make it work. This blog post has outlined some first steps governments can take to rapidly increase zero emission vehicle adoption. As people become more acutely aware of the risks involved with global warming, and the cost of doing nothing, more state and local governments will probably adopt a variety of measures in their toolkit to spur the transfer to zero emission vehicles.















[15] (page 14).