Environmental impact categories commonly used in LCA have been summarised by members of the LCANZ Best Practice Working Group (including Kimberly Robertson, Carla Coelho, Dave Drysdale, Simon Love, James McDevitt and John Andrews). The summaries include information on the cause, outcomes and the relevance to New Zealand.
Please click on the links in the sections below to dowload a PDF for each of the following impact categories:
Abiotic resources such as fossil fuels, minerals, soil and water are non -renewable in human life times. In New Zealand the depletion of energy resources, soil and water is relevant. New Zealand imports 94% of its mineral oil; soil is lost through erosion in over half of the country; and agriculture accounts for 76% of the water consumption.
Changes in land use can reduce the quality of the land use, e.g. if scrubland is converted into a sealed road, but also lead to land competition, since increased amounts of land are used for cities and are no longer available for agriculture, forestry or nature conservation. Less then 50 % of the land in New Zealand is in its original land use.
Global warming potentially causes: rise in sea level, reduced fresh water availability, and therefore impacts on agriculture and food supply, impacts on ecosystems, impacts on human health, but most importantly increased frequency and/or intensity of extreme events (e.g. droughts and floods). New Zealand is committed through the Kyoto Protocol to reduce total greenhouse gas emissions back to 1990 level (by 2012).
The ozone layer is absorbing most of the ultraviolet radiance (UV) from the sun. UV radiance can cause severe damage to both humans and ecosystems, e.g. skin cancer. New Zealand is highly affected by this, especially in November and December when UV radiation is extremely high.
Human toxicity refers to toxic effects on people caused by emission of chemicals and particles. In New Zealand there generally is a low level of toxic contaminants in the environment. The issues of major concern are air pollution from traffic and from burning of solid fuels for domestic heating; water and soil pollution through the use of fertilizers and pesticides. Ecotoxicity describes toxic impacts on all species in terrestrial, freshwater, and marine ecosystems, through heavy metals, sediment, pesticides and other emissions. This can lead to the death of individual organisms or the extinction of species. In New Zealand some organisms and aquatic systems show signs of ecotoxicity.
Photochemical-oxidant formation refers to the formation of toxic pollutants under certain weather conditions in the presence of nitrogen oxides and volatile compounds (VOCs). This is a major problem in big cities overseas, but in New Zealand ground level ozone concentrations are relatively low throughout the country.
Acidification is related to the decrease of pH in soils, waters and the like, threatening the organisms in these systems. In New Zealand levels of acidifying pollutants have been decreasing and are in most parts below air quality guideline levels.
Eutrophication refers to the addition of nutrients from agriculture or sewage treatment facilities to soil or water, which can lead to changes in the biodiversity of these systems. Poor water quality can be found in catchments dominated by agriculture or urban land use. Examples are the lakes in the Bay of Plenty.
Water use can deplete the quantity of water available which can lead irreversible environmental change and harmful impacts on human wellbeing. Water use is becoming an issue in New Zealand, with the Canterbury region being of particular concern.
A word on carbon
... or not only
With greenhouse gas emissions gaining space in the international debate and media, energy efficiency and renewable energy are certainly hot topics. But it is important to remember that life cycle assessment is a tool to assess environmental impacts of all types throughout the life cycle of a product. Many environmental impacts may not correlate to greenhouse gas emissions (for example toxic impacts to human or ecological health) and thus it is important to examine these impacts in addition to greenhouse gas impacts.