Environmental Engineering Reference
In-Depth Information
Transportation, Buildings, and Structures
Impacts on transportation and built structures are primarily the result of
changes in temperature and precipitation beyond what the materials used
to build the roads, rails, bridges, and buildings were designed to withstand.
Transportation can also be impacted by extreme temperatures, heavy rainfall
events, and persistent freeze/thaw conditions.
Climate patterns based on the past century, traditionally used by trans-
portation planners to guide their operations and investments, may no longer
provide a reliable guide to the future (NRC, 2008). In many northern cities,
for example, standard building procedures do not require air conditioning.
As temperatures increase, many of these may require expensive retrofits so
they can continue to be used in extreme heat.
Across the United States, the average number of days per year with
very heavy precipitation has increased significantly over the past 50 years,
with the largest increases (58 and 27 percent, respectively) occurring in the
Northeast and Midwest regions (USGCRP, 2009). This trend is expected
to continue in the future across many regions, as extreme precipitation
events increase (Tebaldi et al., 2006). In both the Midwest and Northeast,
climate change is also expected to increase the amount of rain that falls
in winter and spring, when frozen and/or saturated ground increases flood
risk, while decreasing summer and autumn rainfall (Hayhoe et al., 2008,
2010). Increased frequency of winter and spring rainfall, combined with
more frequent precipitation extremes, could lead to higher peak stream-
flows, particularly under higher temperature change and toward the end of
the century (Cherkauer et al., 2010). Infrastructure impacts in Chicago are
highlighted in Box 5.3.
Energy
Climate change is likely to affect energy demand, production, and
reliability (Wilbanks et al., 2007). Although warmer winter temperatures
are expected to reduce demand for heating energy, observed correlations
between daily mean near-surface air temperature and electricity demand
suggest that warmer summer temperatures and more frequent, severe, and
prolonged extreme heat events will likely increase demand for cooling
energy, particularly as use of air conditioning increases around the world
(see Figure 5.14).
The impact of increasing temperatures on air conditioning demand could
have a disproportionately large effect in already heavily air-conditioned
