Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.
3 Impacts of Climate Change on Transportation T his chapter explores what is known about the potential impacts of climate change on transportation. First, the vulnerability of the trans- portation system to climate change is considered, recognizing, however, that not all changes will have negative impacts. Then, the potential impacts of the major climate change factors of relevance for U.S. transportation iden- tified in the previous chapter are described for each transportation mode. Next, the few studies that have actually assessed the impacts of climate change on transportation in a particular region or metropolitan area are reviewed; these studies provide a good illustration of regional differences in both expected climate changes and impacts. The chapter ends with the com- mitteeâs findings on the impacts of climate change on transportation. VULNERABILITY OF THE TRANSPORTATION SYSTEM TO CLIMATE CHANGE No comprehensive inventory exists of U.S. transportation infrastructure vulnerable to climate change impacts, the potential extent of that exposure, or the potential damage costs. Nevertheless, some salient data can be pieced together from various sources. For example, 53 percent of the U.S. popula- tion lives in counties with coastal areas, although such areas make up only 17 percent of the nationâs contiguous land area (Crossett et al. 2004; U.S. Census Bureau 2005, 28).1 Population density in coastal counties (exclud- 1Coastal areas are defined by the U.S. National Oceanic and Atmospheric Administration as counties and equivalent areas with at least 15 percent of their land area either in a coastal watershed or in a coastal area between watersheds. 79
80 Potential Impacts of Climate Change on U.S. Transportation ing Alaska) is significantly higher than the national averageâ300 versus 98 persons per square mileâreflecting the limited land area involved (Crossett et al. 2004). This population swells in the summer months, as beaches are the top tourist destination (Douglass et al. 2005). Coastal areas are projected to experience continued development pressures as both retirement magnets and tourist destinations. For example, many of the most populous coastal counties located in California, south Florida, and Texas (Harris County), which already experience the effects of hurricanes and other tropical storms, are expected to grow rapidly in the coming decades (Crossett et al. 2004). This growth will generate demand for more transportation infrastructure and increase the difficulty of evacuation in an emergency. Sea level rise, which climate scientists now believe to be virtually cer- tain, in combination with expected population growth, will aggravate the situation, making housing and infrastructure in low-lying coastal areas even more vulnerable to extensive flooding and higher storm surges. An estimated 60,000 miles of coastal highways is already exposed to periodic coastal storm flooding and wave action (Douglass et al. 2005).2 Those high- ways that currently serve as evacuation routes during hurricanes and other coastal storms could be compromised in the future. Although coastal high- way mileage is a small fraction of the nearly 4 million miles of public roads in the United States, the vulnerability of these highways is concentrated in a few states, and some of these routes also serve as barriers to sea intrusion and as evacuation routes (Titus 2002). Coastal areas are also major centers of economic activity. Six of the nationâs top 10 U.S. freight gateways (by value of shipments) (BTS 2007) will be at risk from sea level rise (see Table 3-1). Seven of the 10 largest ports (by tons of traffic) (BTS 2007, 30) are located in the Gulf Coast, whose vulnerability was amply demonstrated during the 2005 tropical storm season.3 The Gulf Coast is also home to the U.S. oil and gas indus- tries, providing nearly 30 percent of the nationâs crude oil production and 2 These estimates were made by using geographic information systems to measure the length of roads in coastal counties, superimposing data from the Flood Insurance Rate Maps of the Federal Emergency Management Agency to indicate those roads along the coast or tidal rivers likely to be inundated by storm surge in a 100-year storm, and finally adjusting the estimate to eliminate flooding from rainfall runoff. 3 The Port of South Louisiana is the nationâs largest port by tonnage and the largest agricultural export facility in the United States (Mineta 2005). Fortunately, it suffered only minor structural damage from Hurricane Katrina.
Impacts of Climate Change on Transportation 81 TABLE 3-1 Top 10 U.S. Foreign Trade Freight Gateways by Value of Shipments, 2005 Shipment Value Rank Port Mode ($ billions) 1 John F. Kennedy International Airport, New York Air 134.9 2 Los Angeles, California Vessel 134.3 3 Detroit, Michigan Land 130.5 4 New York, New York, and New Jersey Vessel 130.4 5 Long Beach, California Vessel 124.6 6 Laredo, Texas Land 93.7 7 Houston, Texas Vessel 86.1 8 Chicago, Illinois Air 73.4 9 Los Angeles International Airport, California Air 72.9 10 BuffaloâNiagara Falls, New York Land 70.5 Source: BTS 2007, 39. approximately 20 percent of its natural gas production (Felmy 2005). Several thousand off-shore drilling platforms, dozens of refineries, and thousands of miles of pipelines are vulnerable to disruption and dam- age from storm surge and high winds of tropical storms, as was recently demonstrated by Hurricanes Katrina and Rita. Those hurricanes halted all oil and gas production from the Gulf, disrupted nearly 20 percent of the nationâs refinery capacity, and closed oil and gas pipelines (CBO 2006).4 Climate scientists believe that global warming is likely to increase the inten- sity of strong hurricanes making landfall, increasing the risk of damage to or lengthening the disruption in the operation of these vital facilities. Inland areas are also likely to experience the effects of climate change. Increased intense precipitation predicted by climate scientists for the con- tinental United States could increase the severity of such events as the great flood of 1993. That event caused catastrophic flooding along 500 miles of the Mississippi and Missouri River system, paralyzing surface transporta- tion systems, including rail, truck, and marine traffic. Major eastâwest traffic was halted for roughly 6 weeks in an area stretching from St. Louis 4 By the end of 2005â4 months after Hurricane Katrina and a little more than 3 months after Hurricane Ritaâroughly one-quarter of crude oil production and one-fifth of natural gas production from the Gulf remained shut down (CBO 2006). Two percent of the nationâs refinery capacity still was not operating.
82 Potential Impacts of Climate Change on U.S. Transportation west to Kansas City and north to Chicago, affecting one-quarter of all U.S. freight that either originated or terminated in the flood-affected region (Changnon 1996). Drier conditions are likely to prevail in the summer in midcontinental regions, such as the Saint Lawrence Seaway. Weather and vessel incidents cause most of the lock downtime on the seaway, but in 2000 and 2001, water levels were at their lowest point in 35 years, reducing vessel carrying capacity to about 90 percent of normal (BTS 2005, 140). If low water levels become more common because of dryer conditions due to climate change, freight movements in the region could be seriously impaired, and extensive dredging could be required to keep shipping chan- nels open (Great Lakes Regional Assessment Team 2000; Quinn 2002). A longer shipping season afforded by a warmer climate, however, could off- set some of the resulting adverse economic effects. The vulnerability of transportation infrastructure to climate change is in part a function of its robustness and degree of protection from exposure to climate change effects (as is the case, for example, with seawalls and lev- ees). It also depends on the amount of redundancy in the system. Box 3-1 illustrates how system redundancies proved critical to the rapid restora- tion of partial rail service during both Hurricane Katrina and the 1993 Mississippi River flood.5 Yet the predominant trend has been for the rail- roads (as well as other owners of infrastructure) to shed uneconomical unused capacity by consolidating operations and abandoning underused lines. Likewise, major businesses, both manufacturing and retail, have reduced operating costs through just-in-time delivery strategies, but with the effect of increasing their vulnerability to disruptions or failures of the transportation system from either natural or human causes. The network character of the transportation system can help mitigate the negative economic consequences of a shock to the system, particularly in the longer term, as shipments can be shifted to alternative modes or other regions can pick up the interrupted service. To illustrate, the Port of Gulfport, Mississippi, which was competing with New Orleans to be the second-largest container port in the Gulf, was 95 percent destroyed by the 30-foot storm surge from Hurricane Katrina (Plume 2005). Subsequently, much of the traffic shifted to other ports while Gulfport undertook major reconstruction of its facilities. On the other hand, the network character 5 See also the discussion later in this chapter of the results of a case study of Hurricanes Katrina and Rita commissioned for this study.
Impacts of Climate Change on Transportation 83 BOX 3-1 Examples of the Role of System Redundancies in the Restoration of Critical Infrastructure Following Natural Disasters Hurricane Katrina significantly damaged rail transport in the Gulf Coast region, particularly eastâwest traffic through the New Orleans interchange rail gatewayâone of only four major rail crossings of the Mississippi River. CSX was the rail carrier most affected, sustaining significant damage to two-thirds of its track mileage between Mobile and New Orleans and to five railroad bridges between Biloxi and New Orleans (M. Hinsdale, presenta- tion to the committee, Jan. 5, 2006). Estimated reconstruction costs were approximately $300 million, or about one-quarter of CSXâs annual operat- ing revenues available for capital investment. Nevertheless, CSX coped with the situation by using âborrowedâ track of other, less hard-hit railroads in the region and by rerouting freight as far north as the St. Louis Mississippi River crossing. CSX has committed to rebuilding its coastal track in the short term but is evaluating less vulnerable alternative routes using exist- ing rail corridors or constructing farther inland. At the time, the flood of 1993 was hailed as the worst natural disaster ever experienced by the U.S. railroad industry. Total physical damages amounted to more than $282 million in 2005 dollarsâ23 percent of which included costs to operate detoured trains (Changnon 2006). In addi- tion, because of the delays, the railroads lost revenues of $198 million. Nevertheless, nearly 3,000 long-distance trains were rerouted onto other railroad lines and some little-used lines bordering on abandonment. System redundancies and operating arrangements with other carriers enabled the affected railroads to continue operatingâmore slowly and at increased costâ but operating nonetheless. of the transportation system can work to magnify the effects of a shock to the system, particularly when critical links are damaged or destroyed. This situation was well illustrated during Hurricane Katrina with the loss of critical highway and rail bridges. POTENTIAL IMPACTS BY TRANSPORTATION MODE The impacts of climate change on transportation infrastructure will differ depending on the particular mode of transportation, its geographic loca-
84 Potential Impacts of Climate Change on U.S. Transportation tion, and its condition. This section is focused on those climate changes and weather parameters identified in the previous chapter (see Table 2-1) that climate scientists agree are most likely to occur over the course of this century and are of greatest relevance to transportation. Potential impacts on all modes of transportâland, marine, and aviationâare considered. However, the discussion is intended to be illustrative rather than com- prehensive in coverage, highlighting major impacts, similarities and differences among modes, and implications for adaptation strategies. Annex 3-1 gives the relevant climate and weather parameters along with potential impacts by transportation mode. In preparing this table, the committee drew on past efforts to identify transportation-sensitive weather conditions, as well as the collective expertise of the committee members. Some notable past reports include the Weather Information for Surface Transportation National Needs Assessment Report (OFCM 2002), the Metropolitan East Coast Assessment (Gornitz and Couch 2000; see detail in the next section), the U.S. Department of Transportation Workshop on Transportation and Climate Change (USDOT 2002), and an article by Black (1990). In addition, the discussion in this section draws heavily on a paper commissioned for this study (Peterson et al. 2006; see Appendix C) that provides a more detailed discussion of the potential impacts of climate change on transportation on the basis of recent global climate simulations. The primary focus here is on the direct impacts of potential climate changes on transportation infrastructure. Nevertheless, many of these effects will be influenced by the environment in which the infrastructure is located. For example, increased precipitation levels in some regions will affect moisture levels in the soil and hydrostatic buildup behind retaining walls and abutments and the stability of pavement subgrades. Runoff from increased precipitation levels will also affect stream flow and sedi- ment delivery in some locations, with potentially adverse effects on bridge foundations. Permafrost decline will affect Arctic land forms and hydrol- ogy, with potentially adverse effects on the stability of road- and rail beds. And sea level rise will affect coastal land forms, exposing many coastal areas to storm surge as barrier islands and other natural barriers dis- appear. Such changes are noted here, but their variability from region to region prohibits further elaboration. There are also likely to be many indirect effects of potential climate changes on transportation. For example, possible climate-caused shifts in
Impacts of Climate Change on Transportation 85 demographics or in the distribution of agricultural production, forests, and fisheries would have implications for road usage and other transport pat- terns between emerging economic centers and urban areas. Transportation patterns could also shift as the tourism industry responds to changes in eco- logically or recreationally interesting destinations. Similarly, climate changes elsewhere in the world that shift markets or demographics could affect the U.S. transportation system. Other indirect effects may be manifested at the interface between mit- igation and adaptation. Likely U.S. regulation of greenhouse gas emissions by the Environmental Protection Agency will affect transportation activities, potentially shifting travel to more energy-efficient modes (see Appendix B). Furthermore, climate changes may present additional challenges to meeting air and water quality standards. For example, warmer summertime temperatures will exacerbate air pollution, partic- ularly ground-level ozone, likely requiring further action to mitigate transportation-related emissions of pollutants. Similarly, changes in runoff resulting from modified precipitation regimes could affect water quality, with implications for roadway treatments. Impacts of Warming Temperatures and Temperature Extremes Land Transportation Modes Land transportation modes comprise highways (including bridges and tunnels); rail (including private rail lines and public transportation); the vehicles that use these facilitiesâpassenger cars, trucks, buses, rail and rail transit carsâand pipelines (recognizing that the latter are buried under- ground in many areas). Projected warming temperatures and more heat extremes will affect all of these modes (see Annex 3-1). The effects of temperature warming are already being experienced in Alaska in the form of continued retreat of permafrost regions (see the discussion of Alaska below), creating land subsidence issues for some sections of the road and rail systems and for some of the elevated supports for aboveground sections of the Trans- Alaska pipeline. Warming winter temperatures have also shortened the season for ice roads that provide vital access to communities and indus- trial activities in remote areas. Alaskaâs situation is quite different from that of many of the lower 48 states, however, where warming temperatures should have less dra-
86 Potential Impacts of Climate Change on U.S. Transportation matic, and in some cases beneficial, effects. In many northern states, for example, warming winter temperatures will bring about reductions in snow and ice removal costs, lessen adverse environmental impacts from the use of salt and chemicals on roads and bridges, extend the construc- tion season, and improve the mobility and safety of passenger and freight travel through reduced winter hazards. Expected increases in temperature extremes, however, will have less positive impacts. More freezeâthaw con- ditions may occur, creating frost heaves and potholes on road and bridge surfaces and resulting in load restrictions on certain roads to minimize the damage. With the expected earlier onset of seasonal warming, the period of springtime load restrictions may be reduced in some areas but is likely to expand in others with shorter winters but longer thaw seasons. Periods of excessive summer heat are likely to increase wildfires, threat- ening communities and infrastructure directly and bringing about road and rail closures in affected areas. Longer periods of extreme heat may compromise pavement integrity (e.g., softening asphalt and increasing rut- ting from traffic); cause deformation of rail lines and derailments or, at a minimum, speed restrictions (Rossetti 2002);6 and cause thermal expan- sion of bridge joints, adversely affecting bridge operation and increasing maintenance costs. Pipelines in the lower 48 states are not likely to experi- ence adverse effects from heat extremes. Marine Transportation Marine transportation infrastructure includes ports and harbors and supporting intermodal terminals and the ships and barges that use these facilities. Expected climate change impacts differ for coastal and inland waterways. Warming winter temperatures, particularly in northern coastal areas, could be a boon for marine transportation. Fewer days below freezing would reduce problems with ice accumulation on vessels, decks, riggings, and docks; the occurrence of dangerous ice fog; and the likelihood of ice jams in ports. The striking thinning (Rothrock and Zhang 2005) and over- all downward trend in the extent (Stroeve et al. 2005) of Arctic sea ice are regarded as a major opportunity for shippers (Annex 3-1). In the short 6 Proper installation of continuous welded rail usually prevents kinks from occurring, but not always (Changnon 2006).
Impacts of Climate Change on Transportation 87 term, continued reduction in Arctic sea ice should result in more ice-free ports, improved access to both ports and natural resources in remote areas, and longer shipping seasons. In the longer term, shippers are look- ing forward to new Arctic shipping routes that could provide significant cost savings in shipping times and distances (see the discussion of Alaska below). For the next several decades, however, warming temperatures and melting sea ice are likely to result in increased variability in year-to-year shipping conditions and higher costs due to requirements for stronger ships and support systems (e.g., ice-capable ship designs, icebreaker escorts, search and rescue support) (ACIA 2004). In addition, improved access to remote areas may increase the risk of environmental degradation to fragile ecosystems. Warming temperatures are also likely to provide longer shipping sea- sons for the St. Lawrence Seaway and the Great Lakes (Annex 3-1). Because of the complex interaction among warmer temperatures, reduced lake ice, and increased evaporation, however, all nine climate model simulations suggest lower lake levels as the climate warms (Great Lakes Regional Assessment Team 2000).7 With lower lake levels, ships will be unable to carry as much cargo, and hence shipping costs will increase, although some of the adverse economic impacts could be offset by a longer shipping sea- son.8 A recent study of the economic impact of climate change on Canadian commercial navigation on the Great Lakes, for example, found that predicted lowering of Great Lakes water levels would result in an esti- mated increase in shipping costs for Canadian commercial navigation of between 13 and 29 percent by 2050, all else remaining equal (Millard 2005).9 Lower water levels could also create periodic problems for river traffic, reminiscent of the stranded barges on the Mississippi River during the drought of 1988 (du Vair et al. 2002). In the longer run, of course, less 7 See in particular Chapter 4 on climate change and shipping/boating. 8 According to the Lake Carriersâ Association, a 1,000-foot-long vessel typically used for intralake transport loses 270 tons of capacity for each inch of draft loss. (Draft is the distance between the water line and the bottom of the vessel.) Oceangoing vessels, sized for passage through the St. Lawrence Seaway, are approximately 740 feet long and lose 100 tons of capacity for each inch of draft lost (Great Lakes Regional Assessment Team 2000). 9 Impacts were estimated on the basis of three climate scenarios: one that assumes a doubling of the atmospheric concentration of CO2 by midcentury and two that assume a more gradual increase in greenhouse gases and include the cooling effects of sulfate aerosols. The study found that economic impacts varied widely by commodity and route.
88 Potential Impacts of Climate Change on U.S. Transportation efficient waterborne commodity movement would likely result in shifts to other transportation modes, such as truck and rail. Increased dredging could offset some of the impacts of climate change, but at a high cost and with potentially negative environmental consequences. Air Transportation Air transportation comprises airports and ground facilities, as well as the airplanes that carry both passengers and freight and the air traffic control system. Warming temperatures and possible increases in temperature extremes will affect airport ground facilitiesârunways in particularâin much the same way that they will affect roads. In Alaska, where use of air transport is atypically high relative to land transportation modes and many airstrips are built on permafrost, continued retreat and thawing of permafrost could undermine runway foundations, necessitating major repairs or even relocation of some landing strips (Annex 3-1; U.S. Arctic Research Commission Permafrost Task Force 2003). In contrast, airports in many of the lower 48 northern states are likely to benefit from reduc- tions in the cost of snow and ice removal and in the environmental impacts of salt and chemical use. Airlines could benefit as well from reduced need for deicing of airplanes. The amount of any reduction, how- ever, will depend on the balance between expected warming and increased precipitation. More heat extremes, however, are likely to be problematic. They could cause heat buckling of runways. Extreme heat can also affect aircraft lift; hotter air is less dense, reducing mass flowing over the wing to create lift. The problem is exacerbated at high-altitude airports. If runways are not sufficiently long for large aircraft to build up enough speed to generate lift, aircraft weight must be reduced or some flights canceled altogether. Thus, increases in extreme heat are likely to result in payload restrictions, flight cancellations, and service disruptions at affected airports, and could require some airports to extend runway lengths, if feasible. An analysis by the National Oceanic and Atmospheric Administration for the Denver and Phoenix airports estimated summer cargo loss (June through August) for a single Boeing 747 of about 17 and 9 percent, respectively, by 2030 because of the effects of increased temperature and water vapor (T. R. Karl and D. M. Anderson, Emerging Issues in Abrupt Climate Change, brief- ing, March 12, 2007).
Impacts of Climate Change on Transportation 89 Impacts of Increased Heavy Precipitation and Sea Level Rise Land Transportation Modes The frequency, intensity, and duration of intense precipitation events are important factors in design specifications for transportation infrastruc- ture. Probabilistic estimates of rainfall intensities for a range of durations (5 minutes to 24 hours) for return periods, or recurrence intervals, of 20, 50, and 100 years have been used by civil engineers for designs of road cul- verts, storm water drainage systems, and road- and rail beds. Projected increases in intense precipitation events will necessitate updating design specifications to provide for greater capacity and shorter recurrence inter- vals, increasing system costs. The most immediate impact of more intense precipitation will be increased flooding of coastal roads and rail lines (Annex 3-1). Expected sea level rise will aggravate the flooding because storm surges will build on a higher base, reaching farther inland (Titus 2002). In fact, the chapter in the Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report on North America identifies coastal flooding from expected sea level rise and storm surge, especially along the Gulf and Atlantic coasts, as one of the most serious effects of climate change (Burkett 2002 in Field et al. 2007). Indeed, several studies of sea level rise project that transporta- tion infrastructure in some coastal areas along the Gulf of Mexico and the Atlantic will be permanently inundated sometime in the next century (Dingerson 2005; Gornitz and Couch 2000; Leatherman et al 2000; Titus 2002). Low-lying bridge and tunnel entrances for roads, rail, and rail tran- sit will also be more susceptible to flooding, and thousands of culverts could be undersized for flows. Engineers must be prepared to deal with the resulting erosion and subsidence of road bases and rail beds, as well as ero- sion and scouring of bridge supports.10 Interruption of road and rail traffic is likely to become more common with more frequent flooding. The impact of sea level rise is limited to coastal areas, but the effect of intense precipitation on land transportation infrastructure and opera- tions is not. For example, a record-breaking 24-hour rainstorm in July 10 Scour is the hole left behind when sediment (sand and rocks) is washed away from the bottom of a river. Although scour may occur at any time, scour action is especially strong during floods. Swiftly flowing water has more energy than calm water to lift and carry sediment downriver. Removal of sediment from around bridge piers or abutments (piers are the pillars supporting a bridge and abutments the supports at each end of a bridge) can weaken and ultimately undermine the integrity of bridges (Warren 1993).
90 Potential Impacts of Climate Change on U.S. Transportation 1996 resulted in flash flooding in Chicago and its suburbs, with major impacts on the urban area. Extensive travel delays occurred on metropol- itan highways and railroads, and streets and bridges were damaged. Commuters were unable to reach Chicago for up to 3 days, and more than 300 freight trains were delayed or rerouted (Changnon 1999). Pipelines may also be affected by increased intense precipitation. For example, federal regulations require that pipelines carrying hazardous materials in the lower 48 states be buried with a minimum of 3 feet of coverâup to 5 feet near heavily populated areas. Intense precipitation can erode soil cover and cause subsidence (i.e., sinking of the earth under- neath the pipeline). Scour and shifting of pipelines are a major problem in shallow riverbeds, where pipelines are more exposed to the elements (B. Cooper, Association of Oil Pipe Lines, personal communication, Dec. 7, 2006). Ultrashallow seabed waters can also be a problem if the pipeline becomes exposed and subject to potential movement and even fracture from continuing storm wave action. Changes in seasonal precipitation levels, with more precipitation falling as rain than snow, can be beneficial but can also create problems in certain areas. For example, Californiaâs transportation infrastructure could be sen- sitive to even modest changes from frozen to liquid precipitation. When precipitation falls as rain rather than snow, it leads to immediate runoff and increases the risk of floods, landslides, slope failures, and consequent dam- age to roadways, especially rural roadways in the winter and spring months (du Vair et al. 2002). Navigable rivers with both rainfall and snowmelt responses would probably see greater winter volume flows associated with a greater risk of flooding (U.S. Global Change Research Program 1999). Marine Transportation Coastal ports and harbor facilities will be affected by increased intense precipitation and sea level rise. Landside facilities will be particularly vul- nerable to flooding from an increase in intense precipitation events and to the impacts of higher tides and storm surges from rising seas (Annex 3-1). Sea level with respect to dock level is an important consideration at both wet and dry docks, general cargo docks, and container berths for clearance of dock cranes and other structures. Changes due to increased intense pre- cipitation and sea level rise could require some retrofitting of facilities. At a minimum, they are likely to result in increased weather-related delays and periodic interruption of shipping services.
Impacts of Climate Change on Transportation 91 The navigability of shipping channels is also likely to change. Some channels may be more accessible to shipping farther inland because of sea level rise. The navigability of others, however, could be adversely affected by changes in sedimentation rates and the location of shoals. In other areas, a combination of sea level rise and storm surge could eliminate waterway systems entirely. For example, the Gulf Coast portion of the intercoastal waterway will likely disappear with continued land subsidence and the dis- appearance of barrier islands. This will bring an end to coastal barge traffic, which helps offset rail and highway congestion; all ships will have to navi- gate the open seas. According to the U.S. Geological Survey, Hurricanes Katrina and Rita alone destroyed 217 square miles of coastal wetlands. This loss represents slightly more than two-fifths of that which scientists had previously predicted would take place over the 50-year period from 2000 to 2050 (Barras 2006). The increased intense precipitation and periodic droughts predicted for the midcontinental United States will affect shipping on the Mississippi and Missouri River system. Increased precipitation could bring a repetition of the floods that devastated travel on the Upper Mississippi River in 1993. Droughts have a greater influence on commercial navigation on the lower portion of the riverâfrom St. Louis to the Gulfâwhere there are no locks and dams and channel depths are entirely dependent on river flows. The 1988 drought, for example, stranded more than 4,000 barges, shifting freight to the railroads, which experienced increased business in hauling grains and other bulk commodities (Changnon 2006; du Vair et al. 2002). In a recent study of climate change impacts on the lock and dam system on the Middle Mississippi, between the Missouri and Ohio Rivers, the U.S. Army Corps of Engineers concluded that the uncertainty associated with predicting future river flows called for a âwait and see,â monitoring approach rather than for expensive infrastructure improvements (Institute for Water Resources 2005). Nevertheless, feasibility studies for navigation projects have a 50-year planning horizon, thus requiring at least some con- sideration of the impacts of climate change and identification of the most robust strategies under a range of different possible scenarios. Air Transportation Several of the nationâs largest airports lie in coastal zones, built along tidal waters, sometimes on fill (Titus 2002). Their runways are particularly vulnerable to flooding and erosion from increased intense precipitation
92 Potential Impacts of Climate Change on U.S. Transportation and, in the longer term, from sea level rise. Some airports, such as New Yorkâs LaGuardia, are protected by dikes (see the discussion below of the Metropolitan East Coast Assessment), but others may require protection. At a minimum, increased intense precipitation is likely to cause increased disruptions and delays in air service and periodic airport closures. Impacts of More Intense Tropical Storms Climate scientists believe that more intense tropical storms are a likely effect of climate change. Three aspects of tropical storms are relevant to transportation: precipitation, winds, and wind-induced storm surge. All three tend to be much greater during strong storms. Such storms tend to have longer periods of intense precipitation; wind damage increases with wind speed; and wind-induced storm surge and wave action can have dev- astating effects. All modes of infrastructure are affected by more intense tropical storms. Sustained storm surge and damaging wave action displaced high- way and rail bridge decks during the recent hurricanes along the Gulf Coast, not to mention the loss of thousands of sign and signal supports. Shipping was disrupted, and barges that were unable to get out of harmâs way in time were destroyed. Airports were closed and sustained wind damage. Refineries were damaged, and barge traffic between offshore drill sites and coastal pumping facilities was suspended. The vulnerability of different transportation modes, as well as their resilience to intense tropi- cal storms, is well documented by the case study of the transportation sectorâs response to and recovery from Hurricanes Katrina and Rita dis- cussed later in this chapter. REVIEW OF ASSESSMENTS FOR PARTICULAR AREAS OR REGIONS Few studies have attempted to examine the potential impacts of climate change on transportation in a particular area or region. Those the com- mittee found are briefly reviewed in this section. The Metropolitan East Coast Assessment This study of the impacts of climate change in the tristate area of New York, New Jersey, and Connecticut focused on transportation infrastructure
Impacts of Climate Change on Transportation 93 because of the enormous value of the Metropolitan East Coastâs (MECâs) highly developed infrastructure to the regionâs nearly $1 trillion economy (Jacob et al. 2007).11 With more than 2,000 km of shoreline and extensive areas of vulnerable residential development and business centers and sup- porting infrastructure, the focus was on the effects of sea level rise. The study used two global climate models, tailored to the MEC area, to describe possible future climate scenarios over the 21st century.12 The pro- jections showed a potential rise in sea level of 0.24 to 1.08 m (nearly 0.8 to 3.5 ft) between the reference year, 1980, and 2080. More important, the combined effect of sea level rise and storm surge could result in flood heights for the 100-year coastal storm of 3.2 to 4.2 m (10.5 to nearly 14 ft) above the current reference height of 2.96 m (nearly 10 ft) for New York City. Thus, projected increases in sea level could raise the frequency of coastal storm surges and related flooding by a factor of 3, on average. Moreover, the return interval of the 100-year storm could shorten to as lit- tle as 4 to 60 years, depending on the climate scenario. Elevation maps of areas within the 3-m (10-ft) reference height above current sea level reveal that roughly 10 percent of the total MEC land areaâportions of lower Manhattan; coastal areas of Brooklyn, Queens, Staten Island, and Nassau County; and the New Jersey Meadowlandsâ could experience a marked increase in flooding frequency (see Figure 3-1). Many critical transportation infrastructure facilities lie at elevations 2 to 6 m (6 to 20 ft) above present sea levelâwell within the range of current and projected coastal storm surges of hurricanes and more frequent norâeasters (see Figure 3-2). Most area rail and tunnel entrance points, for example, as well as three major airports, lie at elevations of 3 m or less.13 11 The study, one of 18 regional components of the U.S. National Assessment of the Potential Consequences of Climate Variability and Change organized by the U.S. Global Change Research program under the Clinton administration, was one of the only assessments that examined transportation infrastructure. 12 The two models used were the United Kingdom Hadley Centre model and the model from the Canadian Centre for Climate Modeling and Analysis. For a more detailed discussion, see Jacob et al. 2000. 13 Some of these facilities are protected but may need modification. For example, the Port Authority of New York and New Jersey (PANYNJ), an active participant in the MEC study, built a dike and levee system to protect LaGuardia Airport. After the severe norâeaster in 1992, PANYNJ built floodgates to protect the Port Authority Trans-Hudson tunnel under the Hudson River, which had flooded and put commuter trains out of operation for 10 days (Jacob et al. 2007).
94 Potential Impacts of Climate Change on U.S. Transportation FIGURE 3-1 Central portion of the MEC study area. Gray shading shows the areas at elevations below 3 m (10 ft) above present mean sea level. [Source: Jacob et al. 2007. (Copyright Elsevier 2007. Reprinted with permission of Elsevier Limited, Oxford, United Kingdom.)] The New York metropolitan area is no stranger to the devastating impacts of flooding. For example, the norâeaster of December 1992 pro- duced some of the worst flooding in the area in 40 years, resulting in an almost complete shutdown of the regional transportation system and evac- uation of many seaside communities (Jacob et al. 2007). More recently, heavy rainstorms in September 2004 and in August 2007 crippled the New York City transit system. Torrential rainfall (nearly 3 inches of rain in a 1-hour period in the 2007 event) overwhelmed the drainage system, designed to handle only about half that amount of rainfall, sending water into the subway tunnels (Chan 2007). Recent emergency planning for
Impacts of Climate Change on Transportation 95 Lowest elevation 50 year/2090 5â10 year/baseline 500 year/baseline 5â10 year/2090 500 year/2090 50 year/baseline Feet Newark Holland JFK LGA Lincoln Passenger Airport Tunnel Airport Airport Tunnel Ship Terminal FIGURE 3-2 Current lowest critical elevations of facilities operated by the Port Authority of New York and New Jersey compared with changing storm elevations at these locations for surge recurrence periods of 10, 50, and 500 years between 2000 (baseline) and the 2090s. Note that 10 ft equals approximately 3 m. [Source: Jacob et al. 2007. (Copyright Elsevier 2007. Reprinted with permission of Elsevier Limited, Oxford, United Kingdom.)] New York has focused on a worst-case scenario evacuation of approximately 2.3 million New Yorkers, many by transit, in the event of a Category 3+ hurricane. Flooding and storm surge will only be exacerbated by sea level rise. The New York metropolitan area is constantly rehabilitating and modern- izing its aging capital stock, providing opportunities to build in new protections against potential increased flooding. The MEC study proposes several measures, including incorporating sea level rise into the design, sit- ing, and construction of new infrastructure facilities or renovation of existing facilities; recognizing sea level rise in federal Flood Insurance Rate Maps used by many local jurisdictions for land use planning and con- struction regulations; instituting land use measures to prevent new or further development in highly vulnerable coastal areas; and constructing strategically placed storm surge barriers, similar to those in operation in
96 Potential Impacts of Climate Change on U.S. Transportation the Netherlands and across the Thames River near London, to protect highly vulnerable and valuable areas. Climateâs Long-Term Impacts on Metro Boston Study The Environmental Protection Agency funded a 3-year project to study the potential impacts of climate change on infrastructure systems, including transportation, in the metropolitan Boston area and to recommend strate- gies for preventing, reducing, or managing the risk (Kirshen n.d.). The long-term economic success and quality of life of the region depend heav- ily on reliable infrastructure systems, which could be adversely affected by climate change. The concern is that global warming may result in sea level rise and increased flooding, higher peak summer temperatures, and more frequent and intense winter and summer storms with higher storm surges. At the same time, continued population and economic growth will result in increased development pressure on already vulnerable coastal and river- ine areas, increasing not only the amount of infrastructure at risk but also the amount of runoff that must be handled by area rivers, streams, and storm water systems (Suarez et al. 2005). The human and economic costs of disruption to infrastructure sys- tems from flooding and storm surge in the area were dramatically illustrated by the devastating storm of October 1996. Drainage systems were inadequate to handle the 100-year storm. Backups and overflows affected several sections of the city, causing $70 million in property damage in addition to disrupting business and personal travel (Kirshen et al. 2004, 71). Portions of the Boston Museum of Fine Arts and Northeastern University were flooded, as were a Green Line tunnel and four rapid transit stations, causing major damage and interrupted ser- vice for several weeks. The study analyzed climate change impacts on seven sectors, includ- ing transportation.14 The impact analysis for land transportation systems focused on flooding and impacts on the road system, emphasizing the effect on system performance rather than on infrastructure damage (Suarez et al. 2005). The methodology involved integrating projected changes in land use, demographics, economic activity, and climatic condi- 14 The sectors were energy use, sea level rise, river flooding, water supply, public health (heat- stress mortality), localized systems (water quality, tall buildings, bridge scour), and transportation.
Impacts of Climate Change on Transportation 97 tions into the urban transportation modeling system of the Boston Metropolitan Area Planning Council (MAPC).15 The model was then used to simulate traffic flows for a range of different flooding scenarios for a base case year (2003) and a future year (2025), incorporating anticipated socioeconomic changes, as well as projected new links or increased capac- ity in the road network.16 Finally, the models were rerun to take into account the aggregate effect of increased flooding on delays and lost trips over the period 2000 to 2100.17 The results show that delays and trips lost between the baseline year 2000 and 2100 would increase by 80 and 82 percent, respectively, as a result of increased flooding attributable to climate change (Suarez et al. 2005, 240). Nevertheless, because of the large number of daily baseline trips in the Boston metropolitan areaâapproximately 14.6 million in 2000âthese percentage increases represent relatively modest effects. The results also reflect the redundancy of the transportation network that is typical of a mature metropolitan area, which lessens but does not eliminate vulnerabil- ity. For example, although coastal areas are more densely populated, the road network is less redundant, so that residents are unable to make trips when the roads become inundated. In contrast, riverine floods result in increased vehicle miles and vehicle hours traveled. Travelers have more alternative routes available, but many are major commuter routes, thereby increasing congestion and time traveled (Suarez et al. 2005). The report concludes that even if one uses high monetized values for lost trips and incremental delays, the impacts are âsignificant, but proba- bly not large enough to justify a major effort for adapting the physical 15 MAPC forecasts population and employment growth to 2025 at the town level, providing the best available estimates of the spatial evolution of people and economic growth in the region. The study assumed that similar growth trends would persist up to 2050 and then remain constant. The Canadian Climate Centre and Hadley Centre climate scenarios used in the New England Regional Assessmentâanother regional component of the U.S. National Assessmentâwere superimposed over time series data on local weather conditions to provide the climate change predictions for 2001 to 2100 (Kirshen et al. 2004). 16 Twelve flooding scenarios were developed to reflect different years of simulation, areas flooded (none, 100-year, and 500-year floodplains), and type of flooding (coastal, riverine, or both). Flood Insurance Rate Maps were used to identify coastal and riverine floodplains, and these were overlaid on maps showing land use and the road networks within the boundary of each traffic analysis zone used in the model (Kirshen et al. 2004). 17 Two climate states were modeledâone assuming no climate change, projecting past trends into the future by bootstrapping from 50 years of rainfall and sea level data for the Boston area, and the second assuming climate changes in line with available climate model predictions. The difference in network performance between the two scenarios was attributed to climate change (Kirshen et al. 2004).
98 Potential Impacts of Climate Change on U.S. Transportation infrastructure to expected climatic conditions, except for some key linksâ (Suarez et al. 2005, 231). The study, however, did not take into considera- tion the potential physical damage to transportation infrastructure and repair costs due to climate change that also must be part of any investment decision. Seattle Audit of Climate Change Impacts Since the early 1990s, Seattle has been a leader in its efforts to reduce greenhouse gas emissions that contribute to climate change (Soo Hoo and Sumitani 2005). Because the impacts of climate change are likely to persist well into the 21st century, however, policy makers have also recognized the need to develop appropriate adaptation strategies. Seattleâs Office of City Auditor initiated a series of reviews of how changes in the climate of the Pacific Northwest region would affect the operations and infrastructure of various city departments. The first review was focused on the Seattle Department of Transportation (SDOT), which is responsible for the cityâs $8 billion transportation infrastructure, including its roadways, most bridges, and bike paths (Soo Hoo and Simitani 2005). The primary changes predicted by climate scientists for the Pacific Northwest in the 21st century are warmer temperatures, rising sea levels, and increased winter precipitation. The study identified five potential types of impact. First, increased winter precipitation could lead to more flooding and landslides, which could damage the cityâs transportation infrastructure and underlying utilities and hamper the mobility and safety of travel.18 More flooding, for example, could overwhelm the existing storm water drainage system, causing soil saturation and surface erosion. It could also exacerbate erosion of soil around roads, bridge footings, and retaining walls. Second, rising sea levels could affect the adequacy of seawall heights and bridge clearances. SDOT had considered sea level rise in developing design standards for a major Alaskan Way Seawall replacement project, but questions were raised regarding whether the projected sea level rise was underestimated. 18Seattle Public Utilities has primary responsibility for responding to emergencies, such as landslides and surface flooding. However, SDOT is primarily responsible when the structural integrity of public streets, bridges, and retaining walls is threatened (Soo Hoo and Sumitani 2005).
Impacts of Climate Change on Transportation 99 Third, increased precipitation and temperatures and sea level rise would adversely affect bridge operations. More than one-third of Seattleâs 105 bridges are currently rated as being in poor condition.19 Warmer tem- peratures could cause greater thermal expansion at bridge expansion joints, affecting bridge operations and adding to maintenance costs. Increased winter precipitation could exacerbate erosion around bridge footings, and rising sea levels could affect bridge clearances (see Figure 3-3). Fourth, warmer temperatures and increased precipitation could cause roadways to deteriorate. SDOT is responsible for approximately 1,500 lane miles of arterial streets and 2,700 lane miles of nonarterial streets. The cityâs arterial streets are in good condition, but there is a backlog of repair and resurfacing projects. Climate changes could shorten street lives (Figure 3-3). Hotter summers could result in pavement softening and buckling and the appearance of heat bumps, although use of warmer- temperature asphalt mix could mitigate some of these effects. Increased precipitation would increase street flooding and tax drainage systems. Finally, warmer and longer summers and reduced summer precipita- tion would place stress on trees and landscaped areas in the cityâs rights- of-way, requiring increased maintenance.20 SDOTâs Urban Forestry unit is already considering the use of drought-resistant plants and other strategies to offset the negative effects of climate change. In response to the report, SDOT noted that it is including climate change as a factor in the scoping of new projects. It is also undertaking a new asset management effort that will focus on replacement cycles for all transportation infrastructure; climate change impacts will be considered as one factor in determining the adequacy of proposed replacement and reha- bilitation projects (E. Paschke, SDOT, personal communication, April 14, 2006). That being said, SDOT noted that the long time frames and uncer- tainties of expected climate changes, coupled with maintenance backlogs and short-term planning horizons for operating budgets, justify âa prudent approach: one that combines watchfulness in following trends in climate 19 According to the 2004 Report of the Citizensâ Transportation Advisory Committee, 37 percent of the cityâs bridges are in âpoor condition or worse,â and 4 percent already face weight restrictions because of critical deficiencies (Soo Hoo and Sumitani 2005, 20). 20 SDOTâs Urban Forestry unit maintains an inventory of 130 acres of land in city rights-of-way. Approximately 30,000 trees are located on city-owned land, with an estimated value of $100 million. Approximately half of the cityâs landscaped areas are currently rated as being in good condition (Soo Hoo and Sumitani 2005, 24).
100 Potential Impacts of Climate Change on U.S. Transportation (a) (b) FIGURE 3-3 Potential impacts of climate change on Seattleâs transportation infrastructure. (a) SDOT already monitors some bridges, such as the Admiral Way Bridge, because of erosion concerns. (Photo courtesy of SDOT.) (b) Increased rainfall could cause more rapid deterioration of pavements in city streets. (Photo courtesy of Seattle Municipal Archives.) (Source: Soo Hoo and Sumitani 2005.)
Impacts of Climate Change on Transportation 101 change, including anticipating how climate change may increase our resource needs, while we continue with our efforts to mitigate the causesâ (Soo Hoo and Sumitani 2005, 46). Finally, SDOT officials recommended an interdepartmental team to coordinate a comprehensive assessment of projections for sea level rise, as well as data on other issues related to cli- mate change, that could be used to revise existing or establish new and consistent standards reflecting climate change across all city infrastructure investment projects (Soo Hoo and Sumitani 2005). Alaska Alaska is already experiencing some of the effects of climate change, such as warming temperatures and continued shrinkage of permafrost regionsâ areas of permanently frozen ground below the surface layerâwith conse- quences for all modes of land transportation.21 Warming temperatures are also affecting marine transportation. Decreased concentrations and extent of sea ice in the Arctic Ocean have lengthened the ice-free shipping season, expanded shipping along the Northern Sea Route, and opened the possi- bility of a Northwest Passage for shipping.22 At the same time, however, more open seas have exposed coastal villages along northern and western Alaska to increased storms and wave action, with attendant erosion. Coastal villages, along with their infrastructure, will need greater protection or may have to be relocated (G. Wendler, Geophysical Institute Climate Center, per- sonal communication, March 2, 2006). As noted earlier, Alaskaâs transportation infrastructure differs from that of the lower 48 states. Although Alaska is twice the size of Texas, both its population and road mileage are more like Vermontâs. Of its 12,700 21 Permafrost refers to soil, rock, or sediment that has remained below 32Â°F for 2 or more consecutive years (ACIA 2004). The 2-year designation is intended to exclude the overlying ground surface layer that freezes each winter and thaws each summer. Regions are classified into continuous permafrost zones, in which the permafrost occupies the entire area, and sporadic or discontinuous permafrost zones, in which the permafrost underlies from 10 to 90 percent of the land and may be only a few meters thick in places. Permafrost is further classified into two types: (a) cold permafrost, where temperatures remain below at least 30Â°F, and the introduction of considerable heat can be tolerated without thawing; and (b) warm permafrost, where temperatures remain just below freezing, and very little additional heat may induce thawing. 22 The Northern Sea Route encompasses all routes across the Russian Arctic coastal seas to the Bering Strait. The Northwest Passage is the name given to the marine routes between the Atlantic and Pacific Oceans along the northern coast of North America that span the straits and the sounds of the Canadian Arctic Archipelago.
102 Potential Impacts of Climate Change on U.S. Transportation miles of roads, for example, only about 30 percent are paved (U.S. Arctic Research Commission Permafrost Task Force 2003, 28). The road and rail networks are concentrated largely in the south-central part of the state, near major population centers. Transport by air is much more common than in most states. Alaska has 84 commercial airports and more than 3,000 airstrips, many of which serve as the only means of transport for rural communities. The state also is home to the Trans-Alaska Pipeline System (TAPS). Two recent studies (ACIA 2004; U.S. Arctic Research Commission Permafrost Task Force 2003) considered the impacts of a warming Arctic on both Alaska and its infrastructure, particularly the effects on permafrost. The band of discontinuous, warm permafrost has been moving northward for some years. For highways, thawing of the permafrost causes settling of the roadbed and frost heaves that adversely affect roadway performance, such as load-carrying capacity. The majority of the stateâs highways are located in areas where permafrost is discontinuous, and dealing with thaw settlement problems already claims a significant portion of highway maintenance dollars [M. Miles, Alaska Department of Transportation and Public Facilities (DOT&PF), personal communication, March 3, 2006]. Nevertheless, a road rehabilitation cycle of about 15 years is sufficiently short to enable engineers to adapt to changing climate conditions. Thus, they are able to anticipate some problems created by thawing prior to con- struction and have developed a number of mitigation techniques.23 In addition, the Cold Regions Research and Engineering Laboratory (CRREL),24 in partnership with DOT&PF and the University of Alaska, has developed a web-based geographic information system toolâthe Alaska Engineering Design Information System (AEDIS)âfor use in monitoring and design. AEDIS provides geographic-specific data on climate factors, such as precipitation levels, permafrost, and snow depth, that can be used to derive engineering design parameters (e.g., load-bearing capacity), schedule maintenance, and select optimum transportation routes (T. Douglas, CRREL, personal communication, March 9, 2006). 23For example, insulation can be placed in the road prism (area of road containing the road surface, cut slope and fill slope), and different types of passive refrigeration schemes can be used, including thermosiphons, rock galleries, and âcold culvertsâ (M. Miles, Alaska DOT&PF personal communication, March 3, 2006). 24The Civil and Infrastructure Engineering Branch of CRREL, part of the U.S. Army Corps of Engineers, conducts applied research and develops innovative engineering solutions for facilities and infrastructure that operate under freezing, thawing, and extreme temperature differences.
Impacts of Climate Change on Transportation 103 Less flexible and longer-lived bridges and large culverts are sensitive to movement caused by thawing permafrost and are more difficult than roads to repair and modify for changing site conditions. Thus, designing these facilities to take climate change into account is more critical than is the case for roads (O. Smith, University of Alaska, Anchorage, personal communi- cation, March 1, 2006). Another impact of climate change on bridges is increased scour. Hotter, dryer summers have led to increased glacial melt- ing and longer periods of high streamflows, leading to both increased sediment transport on rivers and scour at bridge crossings. A network of sonars has been installed on several scour-critical bridges around the state, and the monitoring data are regularly sent to Alaska DOT&PF (J. Conaway, United States Geological Survey, personal communication, March 8, 2006). Temporary ice roads and bridges are commonly used in many parts of Alaska to access northern communities and provide support for the min- ing and oil and gas industries. Rising temperatures have already shortened the season during which these critical facilities can be used (ACIA 2004). Like the highway system, the Alaska Railroad crosses permafrost ter- rain, but the railroad does not extend northward into the zone of continuous permafrost. While frost heave and settlement from thawing affect some portions of the track, increasing maintenance costs, major relo- cations of existing track will not likely be required (U.S. Arctic Research Commission Permafrost Task Force 2003). Alaskaâs airports and airstrips are located throughout the state. A signifi- cant number of airstrips in the southwest, the northwest, and the interior are built on permafrost and thus will require major repairs or relocation if their foundations are compromised by thawing (U.S. Arctic Research Commission Permafrost Task Force 2003). TAPS, which stretches from Prudhoe Bay in northern Alaska to the ice- free port of Valdez in the south, crosses a wide range of permafrost types and varying temperature conditions. More than half of the 800-mile pipeline is elevated on vertical supports over thaw-unstable permafrost to avoid problems of permafrost degradation, soil liquefaction, and land subsidence (U.S. Arctic Research Commission Permafrost Task Force 2003). Because the system was designed in the early 1970s on the basis of permafrost and climate conditions of the 1950â1970 period, it requires continuous monitoring, and some supporting members have had to be replaced. The FederalâState Joint Pipeline Office, which regulates TAPS, and the Alyeska Pipeline Company, which operates it, do not regard
104 Potential Impacts of Climate Change on U.S. Transportation permafrost degradation as a problem, but this assessment does not take into account the Arctic Climate Impact Assessment predictions for the next 30 years (U.S. Arctic Research Commission Permafrost Task Force 2003). Arctic marine transport will benefit from climate changes. Obser- vations over the past 50 years show a decline in the extent of Arctic sea ice in all seasons, with the most prominent retreat in the summer (ACIA 2004). Climate models project an acceleration of this trend, opening new shipping routes and extending shipping seasons along Arctic coastlines, including Alaska. Improved accessibility, however, will not be uniformly distributed. For example, the navigation season25 for the Northern Sea Route is projected to increase from 20 to 30 days per year to about 90 to 100 days by 2080 (ACIA 2004, 83). For trans-Arctic voyages, this route rep- resents up to a 40 percent savings in distance from northern Europe to northeastern Asia and the northwest coast of North American compared with southerly routes via the Suez or Panama Canal. In contrast, reduction in the extent of sea ice may create highly variable conditions in the Northwest Passage, reflecting the complex geography of the Canadian Arctic that could not be captured by the regional climate models used for the Arctic Climate Impact Assessment. In sum, recent climate change assessments show that Alaska is already experiencing the effects of climate change, particularly warming of the Arctic climate and thawing of permafrost. The effects are projected to accelerate during this century (ACIA 2004), and Alaskaâs experience with adaptation may be instructive for some other cold-weather regions of the United States. Most of the stateâs transportation infrastructure was designed for permafrost, and those systems with relatively short rehabilitation cycles relative to projected climate changes will have time to adapt to the changes. Nevertheless, projected changes are likely to require at best increased monitoring of climate conditions and higher maintenance costs, and at worst more major retrofits or even relocation of some facil- ities. According to one transportation professional, the greatest challenge lies not in dealing with the impacts of climate change but in not knowing exactly what changes to expect or when (B. Connor, Alaska University Transportation Center, personal communication, March 9, 2006). 25 The navigation season is generally defined as the number of days per year when there is less than 50 percent sea-ice concentration.
Impacts of Climate Change on Transportation 105 Gulf Coast The committee commissioned a special case study of the transportation sectorâs response to and recovery from Hurricanes Katrina and Rita.26 One of the primary objectives of this study was to examine the vulnerability of the transportation system to a major disruption, with a particular focus on the impact of an interruption on national-level movement of freight. The Gulf Coast is one of the key economic and population centers of the United States, home to more than 15 million Americans located in five states (Texas, Louisiana, Mississippi, Alabama, and Florida) and three major metropolitan areas. The low-lying flat land along the Gulf Coast, skirting the subtropical waters of the Gulf of Mexico, makes the region vul- nerable to major hurricanes, more so than any other region in the United States. However, the geography that makes the coastal area dangerous dur- ing hurricanes also makes it attractive for industrial and commercial development. Several of the nationâs most heavily used ports are located along the Gulf Coast. The Ports of South Louisiana and Houstonâamong the worldâs 10 most heavily used portsâare particularly attractive to inter- national shippers because of the areaâs centralized location with respect to the rest of the nation and its wealth of transportation connections by pipeline, highway, rail, and river. The Gulf of Mexico also contains some of the largest U.S. oilfields and, with its large share of domestic natural gas and petroleum production, combined with its status as a major energy importer, is the epicenter of the U.S. petrochemical industry. Hurricane Katrina was the most destructive and costliest natural disas- ter in U.S. history, claiming more than 1,800 lives and causing an estimated $75 billion in damage. Hurricane Rita, exceeding Katrina in both intensity and maximum wind speed, claimed 120 lives and caused approximately $10 billion in damage. The significantly lower casualty and damage levels of Rita can be attributed to its easterly track, which spared the Houston metropolitan area from the worst of the storm. The unusually large losses of life and physical destruction of Hurricane Katrina resulted from a levee failure and the inability of the floodwaters to recede because so much of New Orleans lies below sea level. A failed evacuation plan for the car-less exacerbated the human toll. Both storms seriously disrupted transporta- tion systems. Key highway and railroad bridges were heavily damaged or 26 This section draws heavily on the commissioned paper, by Grenzeback and Lukmann (2007).
106 Potential Impacts of Climate Change on U.S. Transportation destroyed, necessitating rerouting of traffic and placing increased strain on other routes, particularly other rail lines. Barge shipping was halted, as was export grain traffic out of the Port of New Orleans, the nationâs largest export grain port. The pipeline network was shut down, producing short- ages of natural gas and petroleum products. Despite predictions of long-lasting transportation stoppages, however, the majority of the Gulf Coast highways, rail lines, pipelines, ports, and air- ports were back in service within weeks to a month (see Table 3-2). The worst-damaged bridges took 3 to 6 months to repair. Just three bridges that carry highway US-90 along the edge of the Gulf Coast failed to reopen until mid- to late 2007, approximately 2 years after they were destroyed. The fact that Hurricanes Katrina and Rita had only a modest impact on national-level freight flows can be attributed primarily to redundancies in the transportation system, the timing of the storms, and the track of Hurricane Rita. For example, truck traffic was diverted from the collapsed bridge that carries highway I-10 over Lake Pontchartrain to highway I-12, which parallels I-10 well north of the Gulf Coast. The primary northâsouth highways that connect the Gulf Coast with the major inland transportation hubs were not damaged and were open for nearly full commercial freight movement within days. The railroads were able to reroute intermodal and carload traffic not bound directly for New Orleans through Memphis and other Midwest rail hubs. Although New Orleans is a major rail freight interchange point for eastâwest rail traffic, it is not itself a major origin or destination for rail freight. Had Hurricane Rita struck a larger industrial and transportation hub such as Houston, the effects on rail transportation and freight movement would have been greater and more costly. Timing also played a role. The hurricanes struck before the peak of the corn and soybean export season. Most of the Mississippi River ports and the inland waterway were back in service to handle peak export demand later in fall 2005. Finally, the major pipelines suffered relatively little damage and were able to open within days, as electrical power was restored. The hurricanesâ impacts on national freight flows may have been mod- est, but they were certainly not without cost. A full accounting of the direct costs to repair transportation facilities damaged by Hurricanes Katrina and Rita has not yet been compiled. Reported costs of individual projects shown in Table 3-2 total more than $1.1 billion. Replacement of the I-10 Twin Span Bridge between New Orleans and Slidell, Louisiana, will add nearly another $1 billion, and the repair and replacement of rail lines,
Impacts of Climate Change on Transportation 107 pipelines, ports, waterways, and airports will likely add several billion more to the total. Moreover, the numbers do not include the costs of unreported emergency operating expenditures, lengthy detours, the opportunity costs of lost shipments, and the long-term costs of displaced business and trade. What lessons were learned about the vulnerability of the transporta- tion system from the experience with these two hurricanes? First, with few exceptions, the physical redundancies of a mature transportation system provided sufficient alternative routes to keep freight flows moving with- out major disruption. Where the infrastructure was privately owned (e.g., CSX Railroad), arrangements with other carriers enabled operations to continue. Of course, this outcome might be quite different if multiple cat- astrophic storms were to strike major industrial and transportation hubs in close successionâa plausible scenario in a climate-changed world. Second, restoration of transportation services depended heavily on the availability of electrical power and manpower. Electricity is critical for the highway system to operate traffic lights and signs, for railroads to operate signal systems and crossing gates, for ports to operate cranes and elevators, for airports to power air traffic control facilities and operate nighttime run- way lights, and for pipelines to power pumping stations. Thus, redundancy of power and communications systems is also necessary for the rapid restoration and functioning of freight transportation networks. Similarly, adequate manpower is critical to timely efforts to restore transportation services and staff restoration projects. Because of the devastation wreaked by Hurricane Katrina, many public- and private-sector employees lost family and homes in the storm, and many others evacuated the region; New Orleans itself was closed for more than a month. Thus, major trans- portation companies such as CSX were forced to bring in workers from other locations to staff reconstruction projects. Finally, the storms have resulted in plans for relocating at least one facility and redesigning others in anticipation of future hurricanes. The Port of New Orleans is considering relocating companies and facilities to the main port area on the Mississippi riverfront from the deep-water chan- nel connecting the portâs Inner Harbor navigation canal to the Gulf, where they are more vulnerable to future storms. The cost of the relocation is esti- mated at $350 million. CSX has considered moving its vulnerable rail line inlandâless as a response to hurricane threats than as a response to Mississippi politicians who are interested in the land for casino and hous- ing development (M. Hinsdale, CSX, personal communication, Sept. 12,
108 Potential Impacts of Climate Change on U.S. Transportation TABLE 3-2 Major Transportation Facilities Damaged and Closed by Hurricanes Katrina and Rita Cost to Repair Element of Infrastructure Issue ($ millions) Closed On Closed Until Highways I-10 (Louisiana and Mississippi) Twin Span Bridge (New Orleans, 35.0 LouisianaâSlidell, Louisiana) Eastbound span Heavily damaged Aug. 29, 2005 Oct. 14, 2005 (collapsed spans) Westbound span Heavily damaged Aug. 29, 2005 Jan. 6, 2005 (collapsed spans) I-10 to US-90 ramp bridges Damaged 0.4 Aug. 29, 2005 (Mobile Bay, Alabama) Pascagoula River Bridge Eastbound 312-ft section 5.2 Aug. 29, 2005 Oct. 1, 2005 (Jackson County, Mississippi) damaged US-90 (Louisiana, Mississippi, and Alabama) Chef Menteur Pass Bridge Damaged 2.9 Aug. 29, 2005 Aug. 2007 (East New Orleans, Louisiana) Rigolets Bridge (East New Electrical/mechanical 44.0 Aug. 29, 2005 Dec. 7, 2005 Orleans, Louisiana) damage Bay St. Louis Bridge (Bay Destroyed 266.8 Aug. 29, 2005 May 2007 St. Louis, MississippiâPass Christian, Mississippi) Roadway (Pass Christian, Missis- Heavily damaged 100.0 Aug. 29, 2005 Oct. 29, 2005 sippiâOcean Springs, Mississippi) BiloxiâOcean Springs Bridge Destroyed 338.6 Aug. 29, 2005 Nov. 2007 (Biloxi, MississippiâOcean Springs, Mississippi) CochraneâAfricatown Bridge Damaged (oil rig) 1.7 Aug. 29, 2005 Sept. 1, 2005 (Mobile, Alabama) Mobile Causeway/Tensaw Damaged Aug. 29, 2005 Sept. 2, 2005 Bridge (Mobile Co./Baldwin Co., Alabama) Lake Pontchartrain Causeway (Louisiana) Northbound span Undamaged Aug. 29, 2005 Not closed Southbound span Damaged Aug. 29, 2005 Sept. 24, 2005 I-110 (Biloxi, Mississippi) Damaged 5.0 Aug. 29, 2005 Sept. 1, 2005 LA-1 Damaged Aug. 29, 2005
Aug. 29 Sept. 5 Sept. 12 Sept. 19 Sept. 26 Oct. 3 Oct. 10 Oct. 17 Oct. 24 Oct. 31 Nov. 7 Nov. 14 Nov. 21 Nov. 28 Dec. 5 Dec. 12 Dec. 19 Dec. 26 Jan. 2 Jan. 9 Jan. 16 Jan. 23 Jan. 30 Feb. 6 Feb. 13 Feb. 20 Feb. 27 (continued on next page) Impacts of Climate Change on Transportation 109
110 Potential Impacts of Climate Change on U.S. Transportation TABLE 3-2 (continued) Major Transportation Facilities Damaged and Closed by Hurricanes Katrina and Rita Cost to Repair Element of Infrastructure Issue ($ millions) Closed On Closed Until Rail Corridors CSX: Gulf Coast Mainline Heavily damaged 250.0 Aug. 29, 2005 Jan. 31, 2006 (New Orleans, Louisianaâ Pascagoula, Mississippi) Norfolk Southern: Lake Washed out Aug. 27, 2005 Sept. 12, 2005 Pontchartrain Bridge Union Pacific Minor damage Aug. 29, 2005 Aug. 31, 2005 Burlington Northern Santa Fe: Minor damage Aug. 29, 2005 Sept. 1, 2005 Bayou Boeuf Bridge Canadian National Minor damage Aug. 29, 2005 Sept. 30, 2005 Kansas City Southern Undamaged Aug. 29, 2005 Aug. 31, 2005 Pipelines Louisiana Offshore Oil Port Minor damage Aug. 28, 2005 Sept. 2, 2005 Capline Mostly affected by Aug. 28, 2005 Sept. 1, 2005 power outages Colonial Pipeline Mostly affected by Aug. 28, 2005 Aug. 31, 2005 power outages Plantation Pipeline Mostly affected by Aug. 28, 2005 Sept. 1, 2005 power outages Ports Port of New Orleans Significant damage Aug. 28, 2005 Sept. 12, 2005 175 barges stranded in Out of commission 7.6 New Orleans Port of South Louisiana Damaged Aug. 28, 2005 Port Fourchon Damaged Aug. 28, 2005 Port of Gulfport Mostly destroyed Aug. 28, 2005 Sept. 30, 2005 Port of Lake Charles Minor damage Sept. 22, 2005a Oct. 1, 2005 Port of Houston Undamaged Sept. 22, 2005a Sept. 27, 2005 Aviation Louis Armstrong New Orleans Heavily damaged 15.2 Aug. 28, 2005 Sept. 13, 2005 International Airport Lakefront Airport Heavily damaged 2.0 Aug. 28, 2005 Oct. 19, 2005 GulfportâBiloxi International Airport Heavily damaged 44.0 Aug. 28, 2005 Sept. 8, 2005 Lake Charles Regional Airport Heavily damaged 8.0 Sept. 22, 2005a Sept. 28, 2005 Southeast Texas Regional Airport Damaged 6.0 Sept. 22, 2005a Oct. 8, 2005 Duration of facility closure; now reopened. Duration of facility closure; still closed for repair or replacement. Partially closed. a Closures caused by Hurricane Rita; all others caused by Hurricane Katrina. Source: Grenzeback and Lukmann 2007, 40.
Aug. 29 Sept. 5 Sept. 12 Sept. 19 Sept. 26 Oct. 3 Oct. 10 Oct. 17 Oct. 24 Oct. 31 Nov. 7 Nov. 14 Nov. 21 Nov. 28 Dec. 5 Dec. 12 Dec. 19 Dec. 26 Jan. 2 Jan. 9 Jan. 16 Jan. 23 Jan. 30 Feb. 6 Feb. 13 Feb. 20 Feb. 27 Impacts of Climate Change on Transportation 111
112 Potential Impacts of Climate Change on U.S. Transportation 2006). And at the initiative and recommendation of the Federal Highway Administration (FHWA), almost all of the major river and bay bridges destroyed by the hurricaneâs surge waters will be rebuilt at higher eleva- tions, above the maximum forecast surge levels.27 FINDINGS All modes of transportation are vulnerable to climate change. Just as infra- structure is local and regional, however, so, too, are the impacts of climate change. They will vary depending on the location, mode, and condition of the transportation infrastructure. For example, coastal areas and their infrastructure will be subject to the impacts of sea level rise, while the St. Lawrence Seaway and the Great Lakes may experience lower water lev- els. The infrastructure will experience impacts unique to each mode (e.g., scour on bridge supports), but many impacts, such as flooding and ero- sion, will be common across all modes. The condition of the infrastructure itself will affect the impacts experienced. Increased intense precipitation, for example, could cause accelerated degradation of the surfaces of roads in poor condition. As the examples in this chapter have illustrated, the impacts of climate change on U.S. transportation will be widespread and costly. According to the most recent scientific assessment, the IPCC Fourth Assessment Report, the greatest impact of climate change on North Americaâs transportation system will be coastal flooding, especially along the Gulf and Atlantic Coasts, because of sea level rise, aggravated in some locations by land subsidence and storm surge (Burkett 2002). However, the rate at which these changes are likely to occur remains uncertain. The cur- rent IPCC projections do not include melting of the Greenland ice mass, for example, which could accelerate sea level rise. Projected climate extremes are likely to have a particularly severe impact on transportation infrastructure because the U.S. transportation system was built to typical weather conditions at the time and local weather and climate 27 Hurricane damage to the Gulf Coast bridges resulted primarily from a combination of storm surge and wave crests that simply lifted bridge decks off their supports. Thus, FHWA recommended that a 100-year rather than a 50-year design frequency be used for Interstates, major structures, and critical bridges and that design guidelines take into consideration a combination of wave and surge effects. It was also recommended that risk and cost assessments be conducted (FHWA 2005 in Meyer 2006). New standards have not yet been agreed upon, so it is unclear whether they will take forecasts of sea level rise into consideration.
Impacts of Climate Change on Transportation 113 experience. Expected changes in climate extremes, such as more extreme temperatures, more intense precipitation, and more intense storms, could push environmental conditions outside the range for which the system was designed. This in turn could necessitate changes in design, materials, construction, and operating and maintenance practices. For example, increased flooding from more intense storms could require a combination of physical improvements (e.g., greater pumping capacity, more elevated bridges) and operational measures (e.g., better flood warning and evacua- tion plans, better real-time micro-level weather forecasts). Climate change will create both winners and losers. For example, the marine transportation sector could benefit from more open seas in the Arctic, reducing shipping routes, times, and costs in the long run. In cold regions, expected temperature warming, particularly decreases in very cold days and later onset of seasonal freeze and earlier onset of seasonal thaw, could mean less snow and ice control for departments of transportation and safer travel conditions for passenger vehicles and freight. In all cases, transportation professionals will have to confront and adapt to climate change without knowing the full magnitude of expected changes. The greatest challenge is the uncertainty as to exactly what changes to expect and when. Thus, transportation decision makers will need to adopt a more probabilistic risk management approach to infrastructure planning, design, and operations to accommodate uncertainties about the nature and timing of expected climate changesâa major focus of the next chapter. REFERENCES Abbreviations ACIA Arctic Climate Impact Assessment BTS Bureau of Transportation Statistics CBO Congressional Budget Office FHWA Federal Highway Administration NOAA National Oceanic and Atmospheric Administration OFCM Office of the Federal Coordinator for Meteorological Services and Supporting Research USDOT U.S. Department of Transportation ACIA. 2004. Impacts of a Warming Arctic. Cambridge University Press, United Kingdom.
114 Potential Impacts of Climate Change on U.S. Transportation Barras, J. A. 2006. Land Area Changes in Coastal Louisiana After the 2005 Hurricanes: A Series of Three Maps. USGS Open File Report 06-1274. U.S. Geological Survey. Black, W. R. 1990. Global Warming: Impacts on the Transportation Infrastructure. TR News, No. 150, Sept.âOct., pp. 2â8, 34. BTS. 2005. Transportation Statistics Annual Report. Research and Innovative Technology Administration, U.S. Department of Transportation, Nov. BTS. 2007. Pocket Guide to Transportation. Research and Innovative Technology Administration, U.S. Department of Transportation, Jan. Burkett, V. 2002. Potential Impacts of Climate Change and Variability on Transportation in the Gulf Coast/Mississippi Delta Region. In The Potential Impacts of Climate Change on Transportation, Summary and Discussion Papers, Federal Research Partnership Workshop, Brookings Institution, Washington, D.C., Oct. 1â2, pp. 103â113. CBO. 2006. The Macroeconomic Effects of Hurricanes Katrina and Rita. In The Budget and Economic Outlook: Fiscal Years 2007 to 2016, Jan. Changnon, S. A. (ed.). 1996. The Great Flood of 1993: Causes, Impacts, and Responses. Westview Press, Inc., Boulder, Colo. Changnon, S. A. 1999. Record Flood-Producing Rainstorms of 17â18 July 1996 in the Chicago Metropolitan Area. Part III: Impacts and Responses to the Flash Flooding. Journal of Applied Meteorology, Vol. 38, No. 3, March, pp. 273â280. Changnon, S. A. 2006. Railroads and Weather: From Fogs to Floods and Heat to Hurricanes, the Impacts of Weather and Climate on American Railroading. American Meteorological Society, Boston, Mass. Chan, S. 2007. Flooding Cripples Subway System. New York Times, Aug. 8. Crossett, K. M., T. J. Culliton, P. C. Wiley, and T. R. Goodspeed. 2004. Population Trends Along the Coastal United States: 1980â2008. National Oceanic and Atmospheric Administration, Sept. Dingerson, L. 2005. Predicting Future Shoreline Condition Based on Land Use Trends, Logistic Regression, and Fuzzy Logic. Thesis. Virginia Institute of Marine Science, College of William and Mary, Gloucester, Va. Douglass, S. L., J. M. Richards, J. Lindstrom, and J. Shaw. 2005. An Estimate of the Extent of U.S. Coastal Highways. Presented at 84th Annual Meeting of the Transportation Research Board to the Committee on Hydraulics, Hydrology, and Water Quality, Washington, D.C., Jan. 10. du Vair, P., D. Wickizer, and M. Burer. 2002. Climate Change and the Potential Implications for Californiaâs Transportation System. In The Potential Impacts of Climate Change on Transportation, Summary and Discussion Papers, Federal Research Partnership Workshop, Brookings Institution, Washington, D.C., Oct. 1â2, pp. 125â134. Felmy, J. 2005. Statement of the American Petroleum Institute before the House Transportation and Infrastructure Subcommittees on Water Resources and Environment and on Economic Development, Public Buildings, and Emergency Management, House Transportation and Infrastructure Committee, Joint Hearing on a Vision and Strategy for Rebuilding New Orleans, U.S. House of Representatives, Oct. 18.
Impacts of Climate Change on Transportation 115 FHWA. 2005. Coastal Bridges and Design Storm Frequency. Office of Bridge Technology, Washington, D.C., Sept. 28. Field, C. B., L. D. Mortsch, M. Brklacich, D. L. Forbes, P. Kovacs, J. A. Patz, S. W. Running, and M. J. Scott. 2007. North America. In Climate Change 2007: Impacts, Adaptation and Vulnerability. Contribution of Working Group II to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change (M. L. Parry, O. F. Canziani, J. P. Palutikof, P. J. van der Linden, and C. E. Hanson, eds.), Cambridge University Press, Cambridge, United Kingdom, pp. 617â652. Gornitz, V., and S. Couch. 2000. Sea-Level Rise and Coastal Hazards. In Climate Change and a Global City: An Assessment of the Metropolitan East Coast Region, United States Global Change Research Program, Washington, D.C., pp. 21â46. ccsr.columbia.edu/cig/mec/03_Sea_Level_Rise_and_Coast.pdf. Great Lakes Regional Assessment Team. 2000. Preparing for a Changing Climate: Great Lakes. In A Summary by the Great Lakes Regional Assessment Group (P. J. Sousounis and J. M. Bisanz, eds.), U.S. Global Change Research Program, Oct. Grenzeback, L. R., and A. T. Lukmann. 2007. Case Study of the Transportation Sectorâs Response to and Recovery from Hurricanes Katrina and Rita. Cambridge Systematics, Inc., Jan. 10. Institute for Water Resources. 2005. Climate Impacts on Inland Waterways. Final Report. U.S. Army Corps of Engineers, Alexandria, Va., July. Jacob, K. H., N. Edelblum, and J. Arnold. 2000. Risk Increase to Infrastructure due to Sea Level Rise. Sector Report: Infrastructure, the MEC Regional Assessment. In Climate Change and a Global City: An Assessment of the Metropolitan East Coast (MEC) Region (C. Rosenzweig and W. D. Solecki, eds.). metroeast_climate.ciesin. columbia.edu/reports/infrastructure.pdf. Accessed Apr. 14, 2006. Jacob, K., V. Gornitz, and C. Rosenzweig. 2007. Vulnerability of the New York City Metropolitan Area to Coastal Hazards, Including Sea Level RiseâInferences for Urban Coastal Risk Management and Adaptation Policies. In Managing Coastal Vulnerability (L. McFadden, R. Nicholls, and E. Penning-Roswell, eds.), Elsevier Publishing, Oxford, United Kingdom, pp. 141â158. Kirshen, P. n.d. CLIMB: Climateâs Long-Term Impacts on Metro Boston, Summary. www.tufts.edu/tie/climb. Accessed April 19, 2006. Kirshen, P., M. Ruth, W. Anderson, and T. R. Lakshmanan. 2004. Infrastructure Systems, Services and Climate Change: Integrated Impacts and Response Strategies for the Boston Metropolitan Area. EPA Grant No. R. 827450-01. Aug. 13. Leatherman, S. P., K. Zhang, and B. C. Douglas. 2000. Sea-Level Rise Shown to Drive Coastal Erosion. Eos, Transactions, Vol. 81, No. 6, pp. 55â57. Meyer, M. D. 2006. Design Standards for U.S. Transportation Infrastructure: The Implications of Climate Change. Georgia Institute of Technology, Dec. 18. Millard, F. 2005. The Economic Impact of Climate Change on Canadian Commercial Navigation on the Great Lakes. Canadian Water Resources Journal, Vol. 30, No. 4, pp. 269â280. Mineta, N. Y. 2005. Statement of the Honorable Norman Y. Mineta, Secretary of Transportation, before the Subcommittee on Transportation, Treasury, Housing, and Urban Development, the Judiciary, District of Columbia, and Independent Agencies, Committee on Appropriations, U.S. House of Representatives, Oct. 6.
116 Potential Impacts of Climate Change on U.S. Transportation OFCM. 2002. Weather Information for Surface Transportation: A National Needs Assess- ment Report (WIST). FCM-R18-2002. Washington, D.C. www.ofcm.gov/wist_report/ wist_report.htm. Peterson, T. C., M. McGuirk, T. G. Houston, A. H. Horvitz, and M. F. Wehner. 2006. Climate Variability and Change with Implications for Transportation. National Oceanic and Atmospheric Administration and Lawrence Berkeley National Laboratory, Dec. 6. Plume, J. 2005. Crossroads for Gulfport. Traffic World, Vol. 269, No. 49, Dec. 5, p. 32. Quinn, F. H. 2002. The Potential Impacts of Climate Change on Great Lakes Transportation. In The Potential Impacts of Climate Change on Transportation, Summary and Discussion Papers, Federal Research Partnership Workshop, Brookings Institution, Washington, D.C., Oct. 1â2, pp. 115â123. Rossetti, M. A. 2002. Potential Impacts of Climate Change on Railroads. In The Potential Impacts of Climate Change on Transportation, Summary and Discussion Papers, Federal Research Partnership Workshop, Brookings Institution, Washington, D.C., Oct. 1â2, pp. 209â221. Rothrock, D. A., and J. Zhang. 2005. Arctic Ocean Sea Ice Volume: What Explains Its Recent Depletion? Journal of Geophysical Research, Vol. 110, C01002. Soo Hoo, W. K., and M. Sumitani. 2005. Climate Change Will Impact the Seattle Department of Transportation. Office of City Auditor, Aug. 9. Stroeve, J. C., M. C. Serreze, F. Fetterer, T. Arbetter, W. Meier, J. Maslanik, and K. Knowles. 2005. Tracking the Arcticâs Shrinking Ice Cover: Another Extreme September Minimum in 2004. Geophysical Research Letters, Vol. 32, L04501. Suarez, P., W. Anderson, V. Mahal, and T. R. Lakshmanan. 2005. Impacts of Flooding and Climate Change on Urban Transportation: A Systemwide Performance Assessment of the Boston Metro Area. Transportation Research D, Vol. 10, pp. 231â244. Titus, J. 2002. Does Sea Level Rise Matter to Transportation Along the Atlantic Coast? In The Potential Impacts of Climate Change on Transportation, Summary and Discussion Papers, Federal Research Partnership Workshop, Brookings Institution, Washington, D.C., Oct. 1â2, pp. 135â150. U.S. Arctic Research Commission Permafrost Task Force. 2003. Climate Change, Perma- frost, and Impacts on Civil Infrastructure. Special Report 01-03. Arlington, Va., Dec. U.S. Census Bureau. 2005. Statistical Abstract of the United States: 2006 (125th edition). Washington, D.C., Oct. USDOT. 2002. The Potential Impacts of Climate Change on Transportation, Summary and Discussion Papers. Federal Research Partnership Workshop, Brookings Institution, Washington, D.C., Oct. 1â2. U.S. Global Change Research Program. 1999. Impacts of Climate Variability and Change in the Pacific Northwest. U.S. National Assessment of the Potential Consequences of Climate Variability and Change. National Atmospheric and Oceanic Administration, Office of Global Programs, and JISAO/SMA Climate Impacts Group, University of Washington, Seattle. Warren, L. P. 1993. Scour at BridgesâWhatâs It All About? Prepared by the U.S. Geological Survey in cooperation with the Massachusetts Highway Department. Open File Report 93-W0487. ma.water.usgs.gov/publications/ofr/scour.htm. Accessed July 6, 2006.
ANNEX 3-1 Potential Climate Changes and Impacts on Transportation Impacts on Land Transportation (Highways, Rail, Pipeline) Impacts on Marine Transportation Impacts on Air Transportation Potential Climate Operations and Operations and Operations and Change Interruptions Infrastructure Interruptions Infrastructure Interruptions Infrastructure Temperature: Limitations on Impacts on Impacts on ship- Delays due to Heat-related increases in very periods of pavement and ping due to excessive heat weathering and hot days and construction concrete warmer water in Impact on lift-off buckling of heat waves activity due to construction rivers and lakes load limits at pavements and health and practices high-altitude or concrete safety concerns; Thermal expansion hot-weather facilities restrictions on bridge expan- airports with Heat-related typically begin at sion joints and insufficient weathering of 29.5Â°C (85Â°F); paved surfaces runway lengths, vehicle stock heat exhaustion Impacts on land- resulting in possible at scaping in flight cancella- 40.5Â°C (105Â°F) highway and tions and/or Vehicle overheating street rights- limits on pay- and tire of-way load (i.e., weight deterioration Concerns regard- restrictions) ing pavement More energy con- integrity, e.g., sumption on the softening, ground traffic-related rutting, migra- tion of liquid asphalt; (continued)
ANNEX 3-1 (continued) Potential Climate Changes and Impacts on Transportation Impacts on Land Transportation (Highways, Rail, Pipeline) Impacts on Marine Transportation Impacts on Air Transportation Potential Climate Operations and Operations and Operations and Change Interruptions Infrastructure Interruptions Infrastructure Interruptions Infrastructure sustained air temperature over 32Â°C (90Â°F) is a significant threshold Rail-track deformi- ties; air temp- erature above 43Â°C (110Â°F) can lead to equipment failure Temperature: Regional changes Decreased utility of Less ice accumula- Changes in snow decreases in in snow and ice unimproved tion on vessels, and ice removal very cold days removal costs roads that rely decks, riggings, costs and envi- and environ- on frozen ground and docks; less ronmental mental impacts for passage ice fog; fewer impacts from from salt and ice jams in ports salt and chemi- chemical use cal use (reduction Reduction in need overall, but for deicing increases in Fewer limitations some regions) on ground crew
Fewer cold-related work at airports, restrictions for typically maintenance restricted at workers wind chills below â29Â°C (â20Â°F) Temperature: Thawing of per- Longer ocean Thawing of increases in Arctic mafrost, causing transport season permafrost, temperatures subsidence of and more ice- undermining roads, rail beds, free ports in runway bridge supports northern regions foundations (cave-in), and Possible availabil- pipelines ity of a Northern Shorter season for Sea Route or a ice roads Northwest Passage Temperature: later Changes in Reduced pavement Extended shipping onset of seasonal seasonal weight deterioration season for freeze and earlier restrictions resulting from inland water- onset of seasonal Changes in less exposure to ways (especially thaw seasonal fuel freezing, snow, the St. Lawrence requirements and ice, but Seaway and the Improved mobility possibility of Great Lakes) due and safety more freezeâ to reduced ice associated with thaw conditions coverage a reduction in in some winter weather locations Longer construction season (continued)
ANNEX 3-1 (continued) Potential Climate Changes and Impacts on Transportation Impacts on Land Transportation (Highways, Rail, Pipeline) Impacts on Marine Transportation Impacts on Air Transportation Potential Climate Operations and Operations and Operations and Change Interruptions Infrastructure Interruptions Infrastructure Interruptions Infrastructure Sea level rise, added More frequent Inundation of More severe storm Changes in harbor Potential for Inundation of to storm surge interruptions in roads and rail surges, requir- and port closure or airport runways travel on coastal lines in coastal ing evacuation facilities to restrictions for located in and low-lying areas accommodate several of the coastal areas roadways and More frequent or higher tides and top 50 airports rail service due severe flooding storm surges that lie in to storm surges of underground Reduced clearance coastal zones, More severe storm tunnels and low- under waterway affecting service surges, requir- lying infra- bridges to the highest- ing evacuation structure Changes in density Erosion of road navigability of populations in base and bridge channels; some the United supports will be more States Bridge scour accessible (and Reduced clearance farther inland) under bridges because of Loss of coastal deeper waters, wetlands and while others will barrier shoreline be restricted Land subsidence because of changes in sedimentation rates and shoal locations
Precipitation: Increases in Increases in flood- Increases in Impacts on harbor Increases in delays Impacts on struc- increase in weather-related ing of roadways, weather-related infrastructure due to convec- tural integrity of intense delays rail lines, and delays from wave dam- tive weather airport facilities precipitation Increases in traffic subterranean age and storm Storm water runoff Destruction or dis- events disruptions tunnels surges that exceeds the abling of Increased flooding Overloading of Changes in under- capacity of col- navigation aid of evacuation drainage sys- water surface lection systems, instruments routes tems, causing and silt and causing flood- Runway and other Disruption of backups and debris buildup, ing, delays, and infrastructure construction street flooding which can affect airport closings damage due to activities Increases in road channel depth Implications for flooding Changes in rain, washout, dam- emergency Inadequate or snowfall, and ages to rail bed evacuation plan- damaged pave- seasonal flood- support struc- ning, facility ment drainage ing that affect tures, and maintenance, systems safety and landslides and and safety maintenance mudslides that management operations damage road- ways and tracks Impacts on soil moisture levels, affecting struc- tural integrity of roads, bridges, and tunnels Adverse impacts of standing water on the road base (continued)
ANNEX 3-1 (continued) Potential Climate Changes and Impacts on Transportation Impacts on Land Transportation (Highways, Rail, Pipeline) Impacts on Marine Transportation Impacts on Air Transportation Potential Climate Operations and Operations and Operations and Change Interruptions Infrastructure Interruptions Infrastructure Interruptions Infrastructure Increases in scour- ing of pipeline roadbeds and damages to pipelines Precipitation: Increased Increased Impacts on river Decreased visibility increases susceptibility susceptibility to transportation for airports in drought to wildfires, wildfires that routes and located in conditions causing road threaten trans- seasons drought- for some closures due to portation susceptible regions fire threat or infrastructure areas with reduced directly potential for visibility Increased suscep- increased tibility to mud- wildfires slides in areas deforested by wildfires Precipitation: Benefits for safety Increased risk of Periodic channel Changes in silt Benefits for safety Inadequate or changes in and reduced floods from closings or deposition lead- and reduced damaged pave- seasonal interruptions if runoff, land- restrictions if ing to reduced interruptions if ment drainage precipitation frozen precipita- slides, slope flooding depth of some frozen precipita- systems and river flow tion shifts to failures, and increases inland water- tion shifts to patterns ways and rainfall
rainfall, depend- damage to roads Benefits for safety impacts on ing on terrain if precipitation and reduced long-term via- changes from interruptions if bility of some snow to rain in frozen precipita- inland naviga- winter and tion shifts to tion routes spring thaws rainfall Storms: more More debris on Greater probability Implications for Greater challenge More frequent Damage to frequent roads and rail of infrastructure emergency to robustness of interruptions in landside strong lines, interrupt- failures evacuation infrastructure air service facilities (e.g., hurricanes ing travel and Increased threat to planning, Damage to harbor terminals, (Category 4â5) shipping stability of facility infrastructure navigation aids, More frequent and bridge decks maintenance, from waves and fencing around potentially more Increased damage and safety storm surges perimeters, extensive to signs, light- management Damage to cranes signs) emergency ing fixtures, and and other dock evacuations supports and terminal Decreased expected facilities lifetime of high- ways exposed to storm surge