Environmental Engineering Reference
In-Depth Information
5.5 INFRASTRUCTURE
Infrastructure and Society
Infrastructure provides a broad range of human, environmental, and
economic services including buildings, transportation, waste removal and
treatment, water lines, communications, and electric power grids designed
to improve and sustain our society and our quality of life (Kirshen et al.,
2008b). The importance of infrastructure to an industrialized economy is
reflected in the magnitude of its investments: in 2007, for example, the U.S.
Bureau of Economic Analysis valued the stock of all public non-defense
fixed assets in the United States at approximately $8.2 trillion (Heintz et
al., 2009).
Changing risk of heat waves and droughts, storms and floods, and rising
sea levels are just a few of the hazards climate change poses to infrastructure
(Kraas, 2008). These extreme events confront human systems and constructs
with weather conditions far outside their accustomed range (Wilbanks et
al., 2007). The exposure of society and infrastructure to climate change is
exacerbated by the fact that much of the world's population growth over
the next few decades is likely to occur in urban areas, as they double in
size from 3 to more than 6 billion from 2007 to 2050 (UN, 2008). At the
same time, however, this sector has a greater ability to adapt to changing
conditions than many others, as humans created the systems being affected
by climate change.
In the past, other human stressors on infrastructure—from rapidly ex-
panding urban populations to deteriorating and aging systems, many of them
operating on time scales of years rather than decades—meant that climate
change was rarely considered as a key influence on infrastructure costs.
However, climate changes in recent decades have increased awareness
regarding the risk of significant and costly impacts to infrastructure: whether
from melting permafrost in the Arctic affecting roads, pipelines, and build-
ings, or from storm surges in the Gulf potentially flooding and damaging
homes, cities, highways, and rail lines (USGCRP, 2009; Figure 5.9).
Infrastructure response to climate change is not always continuous but
can be step-wise as system failure may occur above a certain threshold:
whether an underpass tends to flood when more than 2.5 inches of rain falls
in a 24-hour period, for example, or train rails warp only when temperatures
rise above a given threshold. Local conditions can further magnify the sus-
ceptibility of cities to climate-related impacts (Wilbanks et al., 2007). High-
latitude and coastal areas are uniquely vulnerable to climate change.
