Environmental Engineering Reference
In-Depth Information
Table 4.5
Definition of the most common midpoint impact categories used in LCIAs.
Category
Definition
Climate change
This indicator represents the potential change on the planet climate as a
result of human activity and the release of greenhouse gases.
Stratospheric ozone depletion
Ozone in the stratosphere protects the Earth from high doses of
ultraviolet (UV) light from the sun. Several industrial gases released to the
Earth's atmosphere are known to reduce the concentration of ozone in
the stratosphere by accelerating its decomposition. The consequence is
an increase of the incidence of UV radiation to the Earth's surface, which
affects humans and other living organisms.
Acidification
Emissions of nitrogen oxide and sulfur dioxide combine with water in the
atmosphere forming nitric and sulfuric acids. As a result, the pH of the
rain can be substantially decreased and soil and water become acidic.
This higher acidity may harm aquatic and terrestrial species.
Photochemical ozone
production
Formation of ground-level ozone is the result of a combination of
nitrogen oxides (NOx) and volatile organic compounds (VOCs) by the
action of sunlight. Ozone at ground level is an irritant for humans and a
damaging substance for plants.
Eutrophication
Eutrophication is the excessive development of plants in lakes, ponds,
and estuaries stimulated by the release of nutrients (nitrogen and
phosphorus) from human activity. When the vegetation dies and
decomposes, the level of oxygen decreases causing other organisms to
die. Eutrophication may also occur in terrestrial ecosystems because of
the deposition of nitrogen from emissions.
Natural resource depletion
Uses of land surfaces and consumption of resources like water and
minerals cause natural resources depletion. The use of land impacts
ecosystems and the survival of many species. Fresh water resources and
minerals become more difficult to extract and purify thus requiring more
energy for the process.
Terrestrial and aquatic toxicity
It represents the impact of chemical emissions on terrestrial and aquatic
life. When referring to species different than humans, it is normally named
ecotoxicity.
Adapted from Environmental Protection Agency (EPA), 2006, and Jolliet et al., 2004.
Table 4.6
Classification of the most common impact categories according to the scale to which they apply.
Impact category
Scale
Global
Regional
Local
Climate change
X
Stratospheric ozone depletion
X
Acidification
X
X
Photochemical ozone production
X
Eutrophication
X
X
Natural resource depletion*
X
X
X
Terrestrial toxicity
X
Aquatic toxicity
X
Land use
X
X
X
Water use
X
X
Fossil fuels
X
* Natural resource depletion includes the use of land, water, minerals, fossil fuels, and so on that can be also incorporated
in the analysis as independent impacts as shown in the last three rows.
Adapted from Environmental Protection Agency (EPA), 2006, and Bare et al., 2006.
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