Climate change impacts will vary between transport modes and their associated infrastructure, with impacts also varying widely between and within regions. Future changes in freight and passenger traffic may reflect the relative sensitivity of different transport modes to extreme weather events and other climate change impacts. For business, this implies a need to assess supply-chain risk and build redundancy and resilience into logistics networks to account for a higher likelihood of disruption.
Extreme heat will soften paved roads, requiring resurfacing with more durable materials. Frequent freeze-thaw cycles in cold regions will damage both the base and paved surface. More frequent flooding in some regions will increase the need for maintenance, and for investment in drainage and protection.
Unpaved roads are especially vulnerable to intense rainfall. Bridges are exposed to flood events, requiring upgraded design specifications in new construction and retrofitting. It is estimated that adapting bridge infrastructure in the United States will cost USD 140–250 billion over the next 50 years; estimates for Europe are USD 350–500 million per year.
Global warming will reduce the fuel and energy efficiency of public and private vehicles by increasing demand for cooling. It will increase energy consumption in the refrigeration of perishable freight.
The more intense rainfall likely in some regions may reduce driving safety, through poorer visibility and worse surface conditions, although less frost and ice will have the opposite effect.
Thawing permafrost is also a systemic threat. Much polar transport infrastructure depends on permafrost for support in winter or all year. The winter ice road season has already decreased from 200 days in the 1970s to 100 days in some areas of Alaska. Large investments may be required to replace winter ice roads by conventional roads. The winter road network is projected to contract by an average 14% across the eight polar nations by 2050.
Rail beds are susceptible to increased rainfall, flooding and subsidence, sea-level rise and increased incidence of freeze-thaw cycles. Thawing permafrost may lead to ground settlement, which undermines the stability of railways.
Higher temperatures pose a threat to rails through thermal expansion and buckling. Underground electric rail systems (a particular transport feature of cities) are vulnerable to heat waves and flooding. For example, Hurricane Sandy (United States, 2012) flooded eight under-river subway tunnels, severely impacting economic activity.
Source: Unversity of Cambridge
Publication Date: July 2014