Environmental Engineering Reference
In-Depth Information
Our defi nition of impact varies among energy production techniques, so a less
compact way of generating energy does not necessarily mean that an energy produc-
tion technique is more damaging to biodiversity, but simply that it has a larger spatial
area impacted to some degree. Moreover, many energy production techniques actually
have multiple effects on biodiversity, which operate at different spatial and temporal
scales. Biodiversity impacts that are likely to scale with areal impact include habitat
replacement and habitat fragmentation. Energy production impacts on biodiversity not
related to land use intensity include impacts on air quality (e.g., acid rain, particulates),
water quality (e.g., mercury, eutrophication), water consumption (e.g., irrigation wa-
ter, evaporation from hydroelectric reservoirs), and water fl ows (e.g., dam-based hy-
droelectric). Further, the longevity of the impacts described here varies. For example,
radioactive nuclear waste will last for millennia, some mine tailings will be toxic for
centuries, and other mines may be reclaimed for agriculture within decades.
A full discussion of the impacts on biodiversity of energy production is beyond the
scope of this chapter, but one fundamental distinction is worth making. Some energy
production techniques clear essentially all natural habitat within their area of impact.
A review of the literature found this to be true for coal, nuclear, solar, and hydropower,
as well as for the growth of energy crops for biofuels or for burning for electricity.
Energy crop production is a particularly complex situation because even if new energy
crop production occurs on land that was previously in agricultural production, remain-
ing global demand for agricultural commodities may spur indirect effects on land-use
elsewhere, potentially causing an agricultural expansion in areas far from the location
of energy crop production [18]. Other energy production techniques have a relatively
small infrastructure footprint and a larger area impacted by habitat fragmentation and
other secondary effects on wildlife. A review of the literature found that production
techniques that involve wells like geothermal, natural gas, and petroleum have about
5% of their impact area affected by direct clearing while 95% of their impact area is
from fragmenting habitats and species avoidance behavior. Wind turbines have a simi-
lar fi gure of about 3-5% of their impact area affected by direct clearing while 95-97%
of their impact area is from fragmenting habitats, species avoidance behavior, and
issues of bird and bat mortality.
Energy Sprawl in 2030
Regardless of climate change policy, the total new area affected by energy production
techniques by 2030 exceeds 206,000 km
2
in all scenarios (Figure 1B), an area larger
than the state of Nebraska. Biofuels have the greatest cumulative areal impact of any
energy production technique, despite providing less than 5% of the US total energy un-
der all scenarios. Biofuel production, and hence new area impacted, is similar among
scenarios because EIA's economic model suggests that, under current law, incentives
for biofuel production cause expansion of this energy production technique regardless
of climate policy.
Nevertheless, in the scenarios we considered there is a tendency for greater re-
ductions in greenhouse gas emissions to be associated with a greater total new area
affected by energy development, particularly under the Core Cap-and-Trade and Few
Options Scenario (Figure 4). A decrease in US emissions increases the new area
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