Transportation

As the climate warms, there will be a variety of impacts on our transportation system, which is a critical element of our entire economic system.

Sea-level rise and storm surge will increase the risk of major coastal impacts, including both temporary and permanent flooding of airports, roads, rail lines, and tunnels. Flooding from increasingly intense downpours will increase the risk of disruptions and delays in air, rail, and road transportation, and damage from mudslides in some areas. The increase in extreme heat will limit some transportation operations and cause pavement and track damage. In Alaska, the melting of permafrost has already begun to compromise roads, railways, and pipelines. On the plus side, decreased extreme cold will provide some benefits such as reduced snow and ice removal costs.

Federal, state, and local agencies are already taking steps to protect transportation systems from climate change impacts. Adaptation measures across the country are shaped by local impacts. Specific adaptation approaches include:

raising the elevation of critical infrastructure,
changing construction and design standards of transportation infrastructure, such as bridges, levees, roads, railways, and airports,
abandoning or rebuilding important infrastructure in less vulnerable areas.

These adaptations are relatively easy to implement since the transportation infrastructure is in nearly constant need of upkeep — it simply will cost a bit more and will require some foresight in how upgrades are made.

At the same time, changes in transportation are a large part of the solution to the climate problem. In the US, cars and trucks are the largest producer of CO₂, producing 28 percent of emissions annually. To adhere to the Paris Agreement emissions goals the US is going to have to control this output. The Obama administration established mandatory fuel standards for cars and trucks, specifically that automakers were to produce cars with an average of 51 miles per gallon by 2025. These standards were loosened by the Trump administration. However, recently the Biden administration strengthened the Obama fuel standards with stringent rules for cars and trucks produced after 2023, but also is requiring US automakers to produce 50% electric vehicles by 2030. This goal is now clearly feasible as battery technology has advanced so significantly recently. These strategies are a central part of the US pledge to cut emissions by 50% from their 2005 levels by 2030.

On a per passenger basis, planes emit a lot more CO₂ than cars. Short flights are especially polluting so alternative forms of transportation such as trains are environmentally beneficial. Planes inject CO₂ into the upper atmosphere where it has a longer residence time. There are many more cars than planes obviously so the total pollution is higher but cutting back on plane transportation is key to emissions reduction.