Scaling Renewable Transportation through Infrastructure, Policy, and Investment

By Sarah Paper - 2025 Climate & Democracy Leadership Intensive participant, a recent graduate of Scripps College with a degree in Environmental Science & Economics. She is currently working in Washington, DC in PR & communications.

Recent estimates from the EPA and the World Resources Institute estimate the global transportation sector produces about 15% of annual global greenhouse gas (GHG) emissions. Within the sector, road vehicles produce the dominant source of emissions, followed by aviation (approximately 3.5% of global GHG emissions) and maritime shipping (approximately 3% of global GHG emissions).

Pathways for scaling renewable transportation involve multiple modes of changes, including infrastructural developments, investments in financial vehicles backing clean transportation efforts, and political momentum for sustainability in transportation. All these methods support the overall need for a reduction of greenhouse gas emissions to curb the drastic effects of global warming, including rising temperatures, melting glaciers, sea-level rise, extreme weather, and detrimental impacts on ecosystems.

Technological developments for scaling renewable transportation include innovations in electric vehicle (EV) systems, passenger and freight rail, maritime shipping, ferries, and aviation, as well as increasing public transit and urban mobility in metropolitan regions. Innovation in batteries and charging for EV’s, increasing EV integration into the electricity grid, growing green hydrogen power infrastructure, and battery switching, where exhausted EV batteries are traded in for new ones to avoid charging times, are all developments that could promote EV utilization at scale. Within public transit, green hydrogen-powered buses and trains are being integrated in various regions, particularly China, Japan, South Korea, Germany, France, and the Netherlands, because of their lower emissions levels. Autonomous vehicles are becoming operational in cities, which can be beneficial as they optimize energy usage, and have the potential to reduce congestion through efficiency increases. Hydrogen fuel is also emerging as a critical technology for long-haul freight transport. Advances in maritime shipping, ferries, and aviation include battery electric ferries, wind powered cargo vessels, zero carbon marine fuels, including hydrogen and ammonia power sources, short distance electric aviation, and sustainable aviation fuel usage.

Financial instruments that focus on renewable transportation include green bonds, green infrastructure focused funds, and public-private partnerships. Over 50 countries have issued green sovereign bonds, debt securities issued by national governments raising capital for environmentally positive projects. Examples of projects include renewable energy developments, such as wind farms or solar parks, energy efficiency increases, like retrofitting buildings and making smarter electric grids that can adapt to fluctuating demand, and providing cleaner transportation, including electric vehicles and public transportation powered with renewables. Institutions like the World Bank and climate funds also can invest in infrastructure projects, including for cleaner transportation. There are also infrastructure-focused funds which utilize investments towards assets such as EV charging systems, high speed rail, and hydrogen stations, assets with a more stable long-term yield. Additionally, public and private partnerships between governments and corporations can yield additional investment in renewable transportation projects, such as California’s Transit and Intercity Rail Capital Program, which pools local, state, federal, and private capital to promote electric rail and zero emission bus systems. Individuals may look into green stocks, green mutual funds & ETFs, green crowdfunding, or green bonds, while companies can purchase direct equity stakes in clean transportation systems or projects, join a public-private partnership with governments for larger projects, or purchase corporate green bonds. National governments can issue sovereign green bonds, infrastructure investment funds, or utilize multilateral development banks to finance large projects. 

Recent policies in the United States have decreased support for renewable transportation, including the termination of federal EV tax credits in 2025, the halting of the National Electric Vehicle Infrastructure program in 2025, the EPA revoking it’s critical 2009 findings that carbon dioxide and other GHG’s are harmful to public health, the recent loss of EV charging stations previously built under the Biden administration, and the slowdown of EV adoption due to the subsidy removals and additional tariffs for these vehicles prompting price increases. Additionally, the Infrastructure Investment and Jobs Act (IIJA), which had provided $27 billion towards transportation climate programs, was halted with an executive order at the beginning of 2025, with no indication of being resumed.

Possible policy changes at the federal level in the U.S. to promote renewable transportation include the reinstatement of the National EV Infrastructure program with streamlined environmental planning, the reinstatement of the IIJA to promote more active transport, carbon reduction on highways, transit-oriented development, and inter-city rail projects. Additional substantial federal support could include issuance of green bonds and investments in clean tech infrastructure, with opportunities for tax incentives or green bond guarantees to mitigate risk through political administrations.

The Californian government has ambitious goals to provide zero-emission rail by 2050, with current projects including high-speed rail and electrified corridors. In 2024, the 51 mile San Francisco Peninsula rail line was electrified. The commuter rail between San Bernardino and Redlands began operating as a hydrogen-battery hybrid in 2022. California high-speed rail is developing a photovoltaic and battery storage system to utilize renewable energy and its fluctuating energy production, decreasing large amounts of carbon dioxide emitted by traditional vehicles. Local Californian counties have additionally spent millions of dollars providing zero-emission charging stations and bikeway paths. Larger municipalities have ambitious goals to curb or zero-out their emissions in the next 25 years - efforts to reduce emissions in the transportation sector will be key in accomplishing these goals.

Globally, China dominates the market for electric transport, particularly in passenger EV’s and buses. Europe has rapidly developed their electric public transport, with over 50% of city buses sold in the EU in Q4 of 2024 being electric. The markets for electric freight transport in both Asia and Europe is a small percentage, with China pulling ahead implementing electric trucks at scale. In electric aviation, the market size in both Asia and China is expected to increase by over $10 billion respectively in the next 10 years.

The path to a more renewable transportation sector in the United States will require significant coordination, including newer technologies, significant investment, and durable policy systems. Asia and Europe are leading the transition through ambitious electrification targets, hydrogen power integration, and robust public transport expansion. Lacking in consistent federal leadership and long-term infrastructural commitments, the U.S. will require a combination of public and private financing to scale clean technologies and the empowerment of civic action at local and regional levels. The opportunities of decarbonizing transportation will not only aid climate change, but will also improve public health, generate jobs, and protect our future.