The internal combustion engine revolutionized transportation, increased human mobility, opened new educational and economic opportunities, and facilitated the movement of goods around the world.
But these benefits have come at a steep cost to the climate. Fossil-fuel combustion in cars, trucks, trains, planes, and ships represents the leading source (32 percent in 2018) of greenhouse gas (GHG) emissions in the U.S. While cars are the largest source of transportation GHGs today, emissions from trucks, planes, and ships are growing at an even faster rate.
Mitigating the most catastrophic impacts of climate change will necessarily involve decarbonizing transportation. And that will require a complete transformation of the way goods and people move from place to place. Smart, well-designed policies can shape the technology and investment decisions that put the entire U.S. transportation sector on a path to net-zero emissions.
The key components of this transportation revolution are electrification, low-GHG liquid fuels, and more efficient mobility. Electrification (plus a decarbonized grid) is one of the most promising solutions for vehicles that travel shorter distances between refueling. For longer-distance and off-road applications, low-GHG liquid fuels are critical.
More efficient vehicles and increased access to transit are also essential components of a comprehensive decarbonization strategy for transportation. Pushing the transportation sector toward net-zero emissions can also help address historic disparities in access to affordable, clean mobility options for historically disadvantaged communities. Similarly, investments in clean vehicle infrastructure can reduce emissions while addressing transit deserts and providing more access to zero- and low-carbon transportation options in all U.S. communities.
Transportation Policy Focus Areas
Electric vehicles are increasingly competitive with their gas-powered counterparts. But if EVs are going to change the overall trajectory of U.S. emissions, we must support them with technological innovations such as longer-range batteries, market reforms that accelerate their deployment, and smart public policies and investments (in charging infrastructure, for instance).
In long-haul transportation sectors such as aviation and maritime travel, distance makes today’s batteries impractical. We need low-carbon liquid fuels, such as advanced biofuels and electrofuels, instead. New policies to drive innovation and investment in these essential transportation technologies will reduce their cost and accelerate their widespread deployment.
To make transportation more efficient, we need to move more goods and passengers in ways that emit fewer harmful GHGs. Policies and technologies that increase fuel economy and reduce vehicle weight and miles traveled can cut carbon emissions, improving air quality and transit options for everyone.