Ground Transportation

What will it take to make drastic cuts to the emissions from ground transportation, and how much could be realistically cut by 2030?

Bicycles are the most efficient form of human transportation ever invented, in terms of energy expended per calorie per mile. Sadly, bicycles are unlikely to replace cars for journeys of more than a few miles. But to reach the emissions target for 2030, we simply must reduce the number of cars on the road, through improved public transportation and bikeways, more walkable cities and towns, and increased use of shared carpooling arrangements.

Public transportation

Electric buses have been commonplace in Europe for many years. In the US, the number jumped from 300 in 2018 to over 5,500 by the end of 2022, [1] which sounds impressive until you learn that China had a fleet of more than 420,000 by then.[2] It’s comparatively easy and straightforward to replace existing fleets of fossil-fueled buses with electric buses, with few additional costs to municipalities.

Electric trams, subways and trains, on the other hand, require extensive infrastructure that does not yet exist in many parts of the US. In most parts of Europe and large parts of China and elsewhere this infrastructure already exists.

At present, diesel powered trains account for around 0.24 GtCO2-eq of carbon emissions globally (and around 42 MMT in the US). This is less than 0.4% of total emissions. [3] Eliminating those remaining emissions will require electrifying entire rail networks. If that has to be done sooner or later anyway, it makes no sense to invest in all that infrastructure without also creating high-speed rail networks that would serve the needs of the traveling public.

High-Speed Rail

One of the arguments for high-speed rail is that it would cut down on air travel as well as the use of cars. California’s high-speed rail project aims to cut the travel time between San Francisco and Los Angeles to 2 hours and 40 minutes, competing with the 1 hour and 40 minutes it takes to fly between the two, not counting the time to and from airports, checking in, collecting bags, etc.

China built 12,000 miles of high-speed rail network across a country similar in size to the United States in just 9 years.[4] The US High Speed Rail Association believes it can build a similar network in the US, covering 17,000 miles of track, in 20 years.[5] But it requires a big investment.

The US lags significantly behind economically similar countries and groups like China, Japan, and the European Union. As of 2021, the U.S. had 375 miles of high-speed rail, while China had built 26,000 miles of high-speed rail by this point.[6] The state of California voted in 2008 for a high-speed rail to connect the state, but as of 2023 not a single mile of track has been laid, with $9.8 billion spent so far on the preparations.[7] Since the Bipartisan Infrastructure Law, high-speed rail has made slight progress in the US. One project is expecting to begin installing high-speed rail from Los Angeles to Las Vegas by the end of 2023.

Electric cars

Due to rapid advances in battery technology and lowering of prices, electric cars are fast approaching the same price bracket as gasoline-powered and hybrid cars. Some 435,000 fully battery electric vehicles (BEVs)[8] were sold in the US in 2021, up from 322,000 in 2020. That was an 34% increase in one year, but it still represents less than 3% of the 17 million vehicles sold in the US each year.[9]

Following California’s lead, there are now seventeen states with laws that require automakers to sell a certain percentage of electric cars and trucks in their state.[10] Other incentives at the city and state level can help speed up this process.

Used Nissan Leaf EVs are available in US for under $5,000[11]

The IRS tax credit of up to $7,500 for a new electric vehicle brings the cost of an EV closer to that of an equivalent gasoline-powered car, but under new rules that took effect in January 2023, a number of additional factors are taken into account to determine the credit offered.[12] More incentives are needed to put EVs within reach of consumers. 

But most importantly, we still need a clear decision, enacted into federal law, stating that by 2030 all vehicles sold in the United States must be fully electric. That would still leave a large number of gasoline and diesel-powered cars and trucks on the road in 2030. But there would be 85 million fewer by then than the 272 million on the road in the US today. And that would mean 620 MMT less carbon emissions going into the atmosphere in the US alone.

To be selling only electric vehicles in the US by 2030 means increasing EV sales by roughly 40% every year from now to 2030. That’s similar to the growth rate quoted above for 2021, but it’s still a huge rate of change for any industry. In addition to providing incentives to car buyers, the government would need to support the automotive industry through this transition, particularly with continuing investments in battery improvements and in developing clean industrial processes for car production itself.

With only electric vehicles to choose from after 2030, virtually every car would be electric by 2050, simply through normal rates of replacement, although this could also be enforced through legislation. By 2050, a further 1,000 MMT fewer carbon emissions would be going into the atmosphere in the US.

Global sales of EV and Conventional Vehicles 2010-2022[13]



A number of manufacturers are already producing electric SUVs and pickup trucks, so the transformation in this area will follow only slightly behind that for cars.

Heavy-duty trucks and semis are coming along too. Daimler delivered its first all-electric “eCascadia” Freightliner truck at the tail end of 2018,[14] and other manufacturers, including Nikola Motors, Volvo, Thor and MAN-VW have recently come out with all-electric versions of their leading truck models. These still have limited battery range, but Tesla has come out with the first all-electric heavy-duty semi with a 500-mile range.

Daimler’s eCascadia electric semi unveiled, Dec 2018[15]

Government support will again be needed to speed up the transition to electric trucks and to get diesel powered trucks off the roads by 2050. With trucks as well as cars, the deciding factor will be whether we enact new regulations requiring all new vehicles sold in the US by 2030 to be electric. 

[1]  Chard, R., et al. (2023). The Advanced Technology Transit Bus Index: A ZEB Inventory Report for the United States and Canada. (p. 8). CALSTART.

[2] Mordor Intelligence. (2022). China Electric Bus Market Size & Share Analysis.

[3] Slade, R., et al. (2022). Climate Change 2022: Mitigation of Climate Change. In P. R. Shukla & J. Skea (Eds.), Intergovernmental Panel on Climate Change. (p. 620). Working Group III.

[4] Molitch-Hou, M. (2019, March 22).  “The Rest of the Industrialized World has High-Speed Rail, Why Can’t the U.S.?”

[5] USHSR. (n.d.). High Speed Rail Vision Map. Retrieved October 2, 2023, from  

[6] Jones, B. (2023, April 18). High speed trains are racing across the world. But not in America. CNN.

[7] Pettitt, J. (2023, May 17). California’s high-speed rail is running out of money, but progress has been made. CNBC; NBCUniversal.

[8] Electric vehicles (EVs) are normally categorized as Battery Electric (BEV), Plug-In Hybrid (PHEV) or Fuel Cell Electric (FCEV). Non-plug-in hybrids, such as the popular Toyota Prius, are really just high mileage gasoline cars, since the electric motor is normally powered directly from the gasoline.

[9] Szczesny, J. (2022, January 11). EV Sales Jumped 83% in U.S. in 2021, Tesla Still on Top. The Detroit Bureau.

[10] Karnowski, S. (2022, September 3). Over a dozen states grapple with adopting California’s electric vehicle mandate. PBS NewsHour; NewsHour Productions.

[11] Photo taken from used car for sale,

[12] See Parys, S. (2023, September 5). EV Tax Credit: How It Works, What Qualifies. NerdWallet.

[13] Data from International Energy Agency. (2023, February 20). Passenger car sales, 2010-2022. IEA.

[14] Lambert, F. (2018, December 21). Daimler delivers its first all-electric Freightliner truck. Electrek.

[15] Lambert, F. (2018, December 21). Daimler delivers its first all-electric Freightliner truck. Electrek.