The transportation sector’s contribution to climate change is well-documented. The latest EPA greenhouse gas inventory ascribes 26% of U.S. greenhouse gas emissions to cars, trucks, buses, trains, aircraft, construction vehicles and ships, a slightly higher percentage than in 1990. But there has been no comprehensive analysis of how expected climate change impacts will affect the nation’s transportation infrastructure and operations — until now.

A 218-page report released this week by the Transportation Research Board and National Research Council finally examines the issue, painting a grim picture of climate change’s potential threat to roads, rails, airports and ports. The report identifies five principal climate change outcomes of importance to transportation systems:

1. Increases in very hot days and heat waves — threatening the integrity of roads, bridges and rail tracks.
2. Increases in Arctic temperatures (relevant for far North America) — resulting in more ice-free shipping ports, but thawing of permafrost could cause subsidence of roads, rail beds, and bridges.
3. Rising sea levels, combined with storm surges — flooding of roads, rail lines, tunnels, etc. in coastal areas. (The picture at right shows, shaded in gray, areas less than 10 feet above sea level, including Newark Airport, southern Brooklyn, Battery Park City in Manhattan, and the Rockaways in Queens.)
4. Increases in intense precipitation events — causing flooding of roads, rail lines, tunnels, etc., and increases in road washout and damages to rail-beds.
5. More frequent strong hurricanes — raising the probability of infrastructure failures.

NYC transit riders are already familiar with the vulnerability of the 100-year-old system to flooding. Last August’s early morning downpour completely crippled the city’s subway system, and caused long delays on regional commuter rail service as well.

A highly-critical report ordered by then-Gov. Spitzer found the subway’s pumping and drainage system inadequate and criticized the agency’s failure to anticipate the storm (see also MTR # 565). The report prompted the MTA to identify critical infrastructure improvements to help the system address future storm events, some of which are included in the 2008-2013 MTA Capital Program.

Much more will need to be done if the MTA, NJ Transit and other regional transit providers are to plan for and adapt to the inevitable impacts of global warming. The TRB report notes, “Even if drastic measures were taken today to stabilize or totally eliminate [greenhouse gas] emissions, the effects of climate change would continue to be experienced, and U.S. transportation professionals would have to adapt to their consequences.”

State and local DOTs, too, must begin to prepare for climate change impacts. The TRB report recommends that transportation planners at all levels of government embark on an immediate inventory of critical infrastructure and incorporate climate change into their long-term capital improvement plans. The report further recommends that federal land use planning regulations require the inclusion of climate change as a factor in long-range transportation plans and that the planning horizon extend well beyond the current 20-30 year standard.

One recommendation missing from the report is that transit providers anticipate and address future ridership growth as climate change impacts press transportation planners to reduce transport sector emissions by getting people out of their cars and onto buses and trains. This is the double challenge for transit agencies — that they must respond to climate change impacts and serve a critical role in alleviating those impacts.

The report concludes, “The most important step, however, is for transportation professionals to acknowledge that the time has come to confront the challenges posed by climate change.” In fact, that time probably came years ago — governments have a lot of catching up to do.