Framing Climate Change Implications for Infrastructures and Urban Systems - Climate Change and Infrastructure, Urban Systems, and Vulnerabilities - page 35

• Water distribution
• Telecommunications (wireline, wireless, internet) (Hajsaid, et al., 2010)
• Public health (hospitals, urgent care, nursing homes) (Wheeler, 2011)
• Transportation (ports. road, rail, air including pipelines)
Climate impacts that present specific, identifiable risks to these six sectors of
energy and other infrastructures include increases in precipitation, changes in wind
(both damaging and as an emerging source of electricity), increased frequency of storms,
and higher temperatures (Webster, et al., 2005; DEFRA, 2011).
As indicated above, each of these sectors is interdependent with the others because
disruptions within one networked infrastructure will cascade into other infrastructures
which may in turn cause further disruptions in a third infrastructure (Brown, Beyler,
and Barton 2004). This coupling can provide both a source of resilience and a source
of additional vulnerabilities beyond those discovered by examining each infrastructure
independently (Peerenboom, Fisher, and Whitfield, 2001).
During this assessment, examples were found of potential impacts of climate change
on the six engineered infrastructures and their linkages in addition to evidence that the
trend for these linkages is increasing. For example, if weather and climate extremes asso-
ciated with climate change exceed the designed resistance of a structure, or if resistance
has degraded through time, then increased vulnerabilities result. As urban infrastruc-
tures evolve to higher degrees of interconnected complexity, the likelihood of large-scale
cascading outages are likely to increase as risks to infrastructures increase (President's
Commission on Critical Infrastructure Protection, 1997). This outcome in turn leads to
higher levels of vulnerability and consequence within urban infrastructures (Brown, et
al., 2004). This effect is due in part to temporal and spatial interdependencies that are
inadvertently created in an atempt to service changing populations using constrained
resources (Warner, et al., 2009).
For instance, reliance upon and integration of Smart Grid technologies and digital
control systems places public health, communications, and transportation sectors at
increased risk from loss of electric power and in turn power availability increasingly
depends on undisrupted communication networks (Energy Sector Control Systems
Working Group, 2011), while information technologies are critically important for infra-
structure service restoration and recovery. Traffic control is more reliant on communica-
tion technology that is dependent on power availability that in turn relies on undisrupted
fuel deliveries (DEFRA, 2011). Power outages can cascade through direct damage to the
power grid as well as disruptions to control communications, fuel sources, and workers
unable to get to work stations (Brown, et al., 2004). Public health and wastewater man-
agement tolerate only a couple of hours of power disruption before direct sewage spills
are released into public waterways (Chillymanjaro, 2011). Refineries in blackout areas
cannot fulfill deliveries to pipelines with impacts to transportation hubs throughout the
served region. Fuel deliveries to hospital generators must be restored within 1-2 days
to maintain hospital and other lifeline utilities. Loss of power to water distribution sys-
tems reduces pipeline pressure allowing infiltration of contaminated sources (Chillyman-
jaro, 2011). Each networked infrastructure in turn is highly dependent on computerized