As the changing climate poses a growing threat to Bay Area communities, transportation infrastructure is increasingly threatened by rising sea levels and severe weather events. In the coming decades, the transportation sector must take steps to:
• Ensure that transportation networks can withstand climatic changes
• Reduce GHG emissions to avert future climate disruption
There are two main policy approaches to climate change: mitigation and adaptation. Mitigation addresses root causes – like reducing GHG emissions - while adaptation seeks to lower the risks posed by the climate change consequences. Both approaches are necessary, because even if emissions significantly decline in the next decade, adaptation will be needed to handle the global changes already set in motion.
Transportation systems are designed to withstand extreme weather. However, climate change is projected to increase the frequency and severity of future weather events, and transportation networks must be capable of withstanding unprecedented climatic patterns. Regulators are beginning to consider how climate change will affect different transportation systems in the coming decades:
More severe storms could increase disruptions in marine travel and shipping. Runoff from extreme precipitation events could cause a build up of silt and debris, leading to shallower channels. In areas experiencing drought, water levels could periodically decrease and limit inland shipping on rivers.
Though shipping lanes experiencing sea level rise will be able to accommodate larger vessels, other ships could face weight restrictions along inland waterways where water levels are expected to decline. Harbor facilities may need modification to accommodate higher tides and storm surges.
Higher temperatures will damage pavement, rail tracks and bridge joints. Rainfall or snowfall will be concentrated into more intense storms, which may result in flooding or snowstorms and cause damage to the road infrastructure. Coastal roadways, railways and subways are subject to inundation from sea level rise and storm surges.
Periods of extreme heat may cause airplanes to face cargo restrictions, flight delays and cancellations. In some cases, warmer winter temperatures will reduce the need for airplane deicing. On the other hand, severe blizzards and winter storms will likely cause travel and cargo delays, resulting in higher operating costs.
In the winter and spring, increased rains and flooding may disrupt air travel more frequently. Flooding may damage facilities, and airports in low-lying coastal areas - such as the San Francisco International Airport – which are vulnerable to inundation.
In the U.S., federal, state, and local agencies are engaging in incremental adaptation assessment by planning to protect transportation systems from climate change impact.
In 2005, California governor Schwarzenegger mandated the biennial production of a Climate Change Impacts Assessment to identify potential impacts of climate change and offers adaptation strategies. Additionally, California has an inter-agency Climate Action Team responsible for implementing mitigation and adaptation efforts. In 2009, the California Natural Resources Agency released a Climate Adaptation Strategy recommends actions and possible solutions to implement across state agencies. Since the release of the Climate Adaptation Strategy, the state formed a Climate Adaptation Advisory Panel that released a report, Preparing for the Effects of Climate Change- A Strategy for California, which includes adaptation recommendations for sea level rise, dwindling water supply, and wildfires. California also developed Cal-Adapt, an interactive resource that provides climate data, trends, maps, and other information.
The California Department of Transportation is integrating climate considerations into strategic planning. In San Luis Obispo County, Caltrans is moving part of Highway 1 inland due to coastal erosion and sea level rise. Caltrans expects this realignment to protect the iconic road for the next 100 years while minimizing impacts to coastal resources.
According to the 2011; Bay Conservation Development Commission Assessment, the San Francisco Bay Area is particularly vulnerable to sea level rise. There are several agencies and communities in the Bay Area that are concerned about the impacts of sea level rise on ecosystems, the economy, and infrastructure. The Adapting to Rising Tides program is working with community officials and stakeholders to identify climate change impacts and develop feasible strategies to manage risks in Bay Area communities. Hayward and Berkeley are developing for impacts, including those related to sea level rise. The Bay Conservation and Development Commission developed a partnership with the Netherlands to learn effective strategies to deal with sea level rise in low-lying areas.