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1.
Background, aim and scope Considerable debate surrounds the assessment of the environmental impacts and the ethical justification for providing a year-round
supply of fresh produce to consumers in the developed countries of northern Europe. Society is seeking environmentally sustainable
supply chains which maintain the variety of fresh food on offer throughout the year. This paper compares the environmental
impacts of different supply chains providing lettuce all year round to the UK and considers consumers' meanings of—and attitudes
to—available options. Lettuce has been selected as a case study as its consumption has grown steadily during the last two
decades and the supply chains through cold months are protected cropping in the UK and field cropping in Spain; during warm
months, lettuce is sourced from field cropping in the UK.
Materials and methods Data were collected from farms supplying each of these supply chains, and life cycle assessment methodology was used to analyse
a range of impacts associated with producing (from plant propagation to harvesting and post-harvest cooling) and delivering
1 kg of lettuce to a UK Regional Distribution Centre (RDC). The downstream stages (i.e. retailing, consumption and waste management)
are the same regardless of the origin of the product and were omitted from the comparison. The impacts considered included
potential to induce global warming and acidification as well as three inventory indicators (primary energy use, land use and
water use). Qualitative data were collected in order to assess the consumer considerations of purchasing lettuce also during
winter.
Results Importation of Spanish field-grown lettuce into the UK during winter produced fewer greenhouse gas (GHG) emissions than lettuce
produced in UK-protected systems at that time (0.4–0.5 vs. 1.5–3.7 kg CO 2-eq/kg lettuce in RDC). Refrigerated transport to the UK was an important element of the global warming potential associated
with Spanish lettuce (42.5% of emissions), whilst energy for heating dominated the results in UK-protected cultivation (84.3%
of emissions). Results for acidification were more variable and no overall trends are apparent. Results from qualitative social
analysis revealed complex and multidimensional meanings of freshness and suggested that the most striking seasonal variation
in vegetable/salad eating was a tendency to consume more salads in the summer and more cooked vegetables in the winter, thus
suggesting that in-home consumption alone cannot explain the rise in winter imports of lettuce to the UK.
Discussion UK field-grown lettuce had the lowest overall environmental impact; however, those lettuces are only available in summer,
so consumers therefore need to either accept the environmental impacts associated with eating lettuce in the winter or to
switch consumption to another food product in the winter. When lettuces were field-grown in Spain and then transported by
road to the UK, the overall impacts were similar to the UK field lettuces. The variation within farms of the same country
employing different cultivation regimes and practices was bigger than between farms of different countries.
Conclusions This paper has explored the environmental consequences of consuming lettuce year-round in the UK. Whilst recognising the small
sample size, the comparative analysis of the different supply chains does suggest that seasonality can be an important variable
when defining the best choice of lettuce from an environmental point of view.
Recommendations and perspectives Further studies considering more production sites and product types are required to obtain conclusions whose general validity
is clear and for different types of fresh produce. A clear distinction to be made in such studies is whether crops are produced
in open fields or under protection. New characterisation methods are needed for environmental impacts derived from the use
of key agricultural resources such as land and water. Social studies to investigate consumer preferences and the possibility
of moving to more seasonal diets should be an integral part of these studies using samples composed of both urban and rural
consumers and using a mixed methodology with both quantitative and qualitative components.
相似文献
2.
Widespread invasion of riparian ecosystems by the large bamboo-like grass Arundo donax L. has altered community structure and ecological function of streams in California. This study evaluated the influence of
wildfire on A. donax invasion by investigating its relative rate of reestablishment versus native riparian species after wildfire burned 300 ha
of riparian woodlands along the Santa Clara River in southern California in October 2003. Post-fire A. donax growth rates and productivity were compared to those of native woody riparian species in plots established before and after
the fire. Arundo donax resprouted within days after the fire and exhibited higher growth rates and productivity compared to native riparian plants.
Arundo donax grew 3–4 times faster than native woody riparian plants—up to a mean of 2.62 cm day −1—and reached up to 2.3 m in height less than 3 months after the fire. One year post-fire, A. donax density was nearly 20 times higher and productivity was 14–24 times higher than for native woody species. Three mechanisms—fire-adapted
phenology, high growth rate, and growth response to nutrient enrichment—appear to promote the preemption of native woody riparian
species by A. donax after fire. This greater dominance of A. donax after wildfire increased the susceptibility of riparian woodlands along the Santa Clara River to subsequent fire, potentially
creating an invasive plant-fire regime cycle. Moreover, A. donax infestations appear to have allowed the wildfire to cross the broad bed of the Santa Clara River from the north, allowing
thousands of acres of shrubland to the south to burn. 相似文献
3.
Background, aim, and scope Under ISO 14040, normalisation is an optional step in life-cycle impact assessment designed to provide environmental context
by indicating the relative contribution that the product system under investigation makes in the various impact categories,
in comparison to a suitable reference scenario. The challenge for many studies, however, is to provide the appropriate context
by adopting a normalisation reference scenario that is well matched to the product system’s parent environment. Australia
has a highly urbanised population, mainly contained in just eight capital cities. In the context of normalising environmental
impacts against the profile of an ‘average’ Australian, this poses a unique problem, compared to other industrialised regions
of the world. This study aims to use publicly available data on environmentally relevant emissions and non-renewable resource
consumption in 2005/2006 to develop regional normalisation data for Australia, at both inventory and characterisation levels.
Methods The regionalised inventory of emissions and resources production is constructed using a framework of 60 regional Statistical
Divisions from the Australian Standard Geographical Classification system. Data from the National Pollutant Inventory, Australian
Greenhouse Emissions Information System and the Australian Bureau of Agricultural and Resource Economics (energy and mineral
statistics) are used as the basis for the inventories. These data could subsequently be used by any LCA practitioner to construct
characterisation or normalisation data by impact category, according to any preferred life-cycle impact assessment methodology,
for any of 60 regions in the country. In this study, the regionalised inventory data were assessed using the CML 2001 baseline
and IMPACT 2002+ life-cycle impact assessment methods in SimaPro v.7.1.5.
Results Characterisation results from the two LCIA methods for Australia’s eight state and territory capital cities are presented,
together with an overall national profile. These data are also shown on a per capita basis to highlight the relative environmental
profiles of citizens in the different cities. Interestingly, many significant impacts occur outside of the capital cities
but are linked to facilities providing the majority of their services and products to these urban centres (e.g. power stations,
minerals processing). Comparison of the average Australian data with the Netherlands, Western Europe and the World shows the
results to be broadly similar.
Discussion Analysis of the CML 2001 baseline characterisation results, on a per capita basis, shows substantial differences between the
major cities of the country. In each impact category, these differences can be successfully traced to specific emissions in
the raw data sources, the influence of prevailing climate conditions, or factors such as the mix of non-renewable energy resources
in each state. Some weaknesses are also evident in the collection and estimation techniques of the raw data sources and in
the application of European-based impact assessment models. Australia is a net exporter of many products, particularly natural
resources. Therefore, a significant part of the characterisation data presented here for Australia represents products that
will be consumed in other parts of the world. Similarly, at a regional level, there will be many inventory items produced
in one area yet consumed in another. In this way, the impacts associated with consumption (particularly in densely populated
but largely industry-free cities) are dissipated into other production centres.
Conclusions This study provides the first set of comprehensive inventory and characterisation data for Australia from a production perspective,
disaggregated at a regional level. Despite Australia’s unique spatial demography, it is now possible to properly characterise
the relative significance of environmental impacts occurring in any of 60 specific regions across the country.
Recommendations and perspectives Australia’s unique concentration of urban populations demonstrates the importance of regionally specific environmental assessments.
Whilst the data presented in this study will be of most use to Australian LCA practitioners, it is also demonstrative of the
broader global distribution of environmental impacts between urban and non-urban areas. The disconnection of environmental
impacts between the place of production and the place of consumption is highlighted by this study and should be considered
in any studies using these normalisation data for environmental profiling.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
4.
Woodfuels currently supply 7 percent of worldwide energy use and are much more important in developing than developed countries. Worldwide fuelwood use may be slowly declining, while charcoal production is increasing. In developing countries, woodfuel comes from natural forests, woodlands, shrublands, plantations and trees outside forests; the last is often the most important source. In developed countries, woodfuels are largely from industrial roundwood processing where up to 50 percent of logs may be used for energy. In urban areas, of both developing and developed countries, woodfuels also arises from wood processing and construction and other urban residues including tree trimming. Currently, apart from some nonindustrial plantations and the small areas of energy plantations, woodfuel largely results from by-products and residues. Forest plantation may currently provide 15 to 20 percent of all fuelwood and this contribution will rise due to continued tree planting plus the rapidly increasing industrial plantation harvest. However, forest and woodfuel-use data are of uneven quality, making estimates tenuous. There is potential to increase the amount of woodfuels in developed countries but its use will depend on fossil fuel price increases, and on ecological and social issues. In Nordic countries, forest residue use has grown, being underpinned by carbon taxes and research and development. Site nutrient conservation is assisted by leaving foliage on site and by returning the ash after burning. Leaving bark on site may be important for eucalypts. In developing countries participatory programmes are critical for encouraging tree planting. Farmers seldom plant for fuelwood alone. Large-scale fuelwood plantations programs have not always been successful. Agroforestry practices are often practiced as they provide multiple benefits, including the provision of woodfuel. Silviculture should be readily adoptable, with special attention being given to species selection, high-quality planting stock, establishment methods and protection from animals. Because of woodfuel's low relative value, energy is seldom a management objective of industrial plantations. However, often silviculture could be altered to increase bioenergy output, particularly with those sawlog regimes based on low stockings and non-extraction thinnings, and through more intensive silviculture. As a supplement to current silvicultural decision-making tools, energy analysis of silvicultural options would assist in efficient allocation of fossil fuels. 相似文献
5.
Calculation of Cumulative Energy Demand (CED) of various energy systems and the computation of their Energy Yield Ratio (EYR)
suggests that one single renewable energy technology cannot be said to be the best. Due to the difference in availability
of renewable energy sources, their suitability varies from place to place. Wind energy converters, solar water heating systems
and photovoltaic systems have been analysed for different types of locations. Comparing the general bandwidth of performance
of these technologies, however, the wind energy converters tend to be better, followed by solar water heating systems and
photovoltaic systems.
Since a major part of the methodology of finding CED is very close to that of life cycle assessment and also because of the dominance of environmental impacts caused by the energy
demand in the entire life cycle of any product or system, it is suggested that the CED can be used as an indicator of environmental impacts, especially in the case of power producing systems. Keywords: Cumulative
energy demand; life cycle assessment; energy yield ratio; photovoltaics; solar water heating; wind energy Abbreviations: CED
— Cumulative Energy Demand; EYR — Energy Yield Ratio; LCA — Life Cycle Assessment; Photovoltaics — PV; WEC — Wind Energy Converters 相似文献
6.
Anthropogenic disturbances have serious impacts on ecosystems across the world. Understanding the effects of disturbance on woodlands, especially in regions where local people depend on these natural resources, is essential for sustainable natural resource management and biodiversity conservation. In this study, we evaluated the effects of anthropogenic disturbance, specifically selective logging of Brachystegia floribunda, on woodlands by comparing species composition, species diversity and functional diversity of woody plants between disturbed and undisturbed woodlands. We combined species data and functional trait data for leaves, fruits and other traits related to resource and disturbance responses to calculate functional indices (functional richness, evenness and divergence) and community‐weighted means of each trait. Shifts in taxonomic species composition were analysed using nonmetric multi‐dimensional scaling. Species composition differed significantly between disturbed and undisturbed woodlands. Tree density was greater in disturbed woodlands, whereas evenness, functional evenness and functional divergence were greater in undisturbed woodlands. In terms of forest cover, selective logging of B. floribunda appeared to have little impact on Miombo woodlands, but some shifts in functional traits, such as the shift from a deciduous to evergreen phenology, may increase the vulnerability of these ecosystems to environmental change, especially drought. 相似文献
7.
A dissolved air flotation (DAF) system upgrade was proposed for an urban paper mill to recycle effluent. To understand the influence of operating variables on the environmental impacts of greenhouse gas (GHG) emissions and water consumption, a dynamic supply chain model was linked with life cycle assessment (LCA) to produce an environmental inventory. Water is a critical natural resource, and understanding the environmental impacts of recycling water is paramount in continued development of sustainable supply chains involving water. The methodology used in this study bridged the gap between detailed process models and static LCA modeling so that operating variables beyond discrete scenario analysis could be investigated without creating unnecessarily complex models. The model performed well in evaluating environmental impacts. It was found that there was no single optimum operating regime for all environmental impacts. For a mill discharging 80 cubic meters of effluent per hour (m 3/hour), GHGs could be minimized with a DAF capacity of 17.5 m 3/hour, while water consumption could be minimized with a DAF capacity of 25 m 3/hour, which allowed insight into where environmental trade‐offs would occur. The study shows that more complexity can be achieved in supply chain modeling without requiring a full technical model. It also illustrates the need to consider multiple environmental impacts and highlights the trade‐off of GHG emissions with water consumption in water recycling. The supply chain model used in this water treatment case study was able to identify the environmental trade‐offs from the operating variables selected. 相似文献
8.
Methodology is developed for linking the urban metabolism (UM) to global environmental stresses on the carbon (C) cycle, nitrogen (N) cycle, and biodiversity loss. UM variables are systematically mapped to the drivers of carbon, nitrogen, and biodiversity impacts. Change in mean species abundance is used as metric of biodiversity loss, by adopting the dose‐response relationships from the GLOBIO model. The main biodiversity drivers related to UM included here are land‐use change (LUC) and atmospheric N deposition. The methodology is demonstrated by studying the nexus for Shanghai in 2006, based on energy and soybean consumption. Results for Shanghai show a strong nexus between C, N, and biodiversity impact due to electricity consumption and energy used in manufacturing industries and construction. Prioritization of the shift away from coal energy will therefore lead to lowering the urban growth impact on all three dimensions. Road transportation, domestic aviation, and the metal industry impact only the C footprint highly, whereas district energy impacts only biodiversity loss highly, showing a weak nexus. Among the global impacts of soybean consumption in Shanghai on biodiversity loss (due to LUC only), the highest impact occurs in Uruguay (0.52%) followed by Brazil (0.05%) and Argentina (0.02%). The local impact on biodiversity loss (i.e., within China) of soybean consumption in Shanghai is 1.03%. However, the methodology and results are limited due to the partial inclusion of drivers, a carbon footprint based on carbon dioxide emissions only, and limitations of biodiversity loss models. Potential to overcome methodological limitations is discussed. 相似文献
9.
The reproductive characteristics and feeding conditions of the spider, Nephila clavata, were examined at some urban and non-urban woodland sites. More than 80% of females were gravid by late October in both non-urban
and large urban woodlands, whereas only 10%–30% were gravid in small urban woodlands. The expected number of eggs per female
in mid-October was also lower in the small urban woodlands, although body length was not reduced. This suggests that reproductive
failure was not caused by food shortage during the nymphal stage. Relative food consumption rate, prey size, biomass and size
of potential prey during the adult stage all tended to be lower in small urban woodlands. These results suggest that decreased
reproduction of N. clavata in small urban woodlands is caused by food shortage during the adult stage, particularly a shortage of large insects. 相似文献
10.
The increasing rate of urban sprawl continues to fragment European landscapes threatening the persistence of native woodland
plant communities. The dynamics of woodland edges depend on the characteristics of woodland patches and also on landscape
context. Our aim was to assess the extent of edge influences on the understorey vegetation of small native woodlands in rural
and urban landscapes. The study was carried out in two cities of north-western France. Ten comparable woodlands, each of about
1.5 ha, were surveyed; five were situated adjacent to crops and five adjacent to built-up land. Vascular plant species were
recorded in 420 3 × 3 m plots placed at seven different distances from the edge (from 0 to about 45 m from the edge). Soil
pH, light levels, level of disturbance and tree and shrub cover were also recorded. Plant species were first classified as
non-indigenous or indigenous and then three groups of indigenous species were distinguished according to their affinity for
forest habitat (forest specialists, forest generalists and non-forest species). We inferred certain ecological characteristics
of understorey vegetation by using Ellenberg values. An inter-class correspondence analysis was carried out to detect patterns
of variation in plant community composition. Linear mixed models were used to test the effects of adjacent land use, distance
from the edge and their interactions on the species richness of the different groups and on the ecological characteristics
of vegetation. Total species richness, richness of forest generalists and of non-forest species decreased from edge to interior
in both urban and rural woodlands. The number of non-indigenous species depended mainly on urban–rural landscape context.
Urban woodland edges were not as rich in forest specialists as rural edges. More surprisingly, the number of forest specialists
was higher in rural edges than in rural interiors. Community composition was mainly affected by urban–rural context and to
a lesser degree by the edge effect: the community composition of urban edges resembled that of urban interiors whereas in
rural woodlands vegetation near edges (up to 10 m) strongly differed from interiors with a pool of species specific to edges.
Urban woodland vegetation was more nitrophilous than rural vegetation in both edges and interiors. A major difference between
urban and rural vegetation was the distribution of basiphilous species according to distance from the edge. Generally edge
vegetation was more basiphilous than interior vegetation however the presence of basiphilous species fell off quickly with
distance from the edge in rural woodlands (in the first 10–15 m) and more slowly (from 25 m onwards) in urban woodlands. This
pattern was linked to variation in measured soil pH. As regards the conservation of flora in small native woodlands, it appeared
that invasion of exotic and non-forest species was currently limited in both urban and rural landscape contexts but might
pose problems in the future, especially in urban woodlands. Forest species were not negatively affected by the edge effect
and indeed edges seemed to provide important habitats for this group. Hence conservationists should pay particular attention
to the protection of edges in urban woodlands. 相似文献
11.
Using the city of Toronto as a case study, this article examines impacts of energy stocks and flexible demand in the urban metabolism on the resilience of the city, including discussion of directions for further study of the resiliency of the urban metabolism. An important element developed is the nominal residence time of the energy stocks. This value defines how long an energy stock lasts under typical patterns of energy use. The findings suggest that the residence times of many sources of energy overcome vulnerability when energy supply shocks last on the order of hours or a few days, but that the measure is limited to assessing only certain types of commonly used energy sources in aggregate terms. Discussion is included on the uncertainty of this measure and on the metabolic and resiliency implications of new technologies intended to reduce energy use and improve sustainability of cities and the use of the urban metabolism as a means of comparison. The methodology employed highlights how waste energy could be used to increase the resiliency of the city's water supply, but also how the study of the urban metabolism would benefit from a more disaggregate form in the study of sustainable and resilient cities. 相似文献
12.
This paper presents an overall bioinvasion impact assessment on the scale of a large marine region—the Baltic Sea, as defined
by the Helsinki Commission. The methodology is based on a classification of the abundance and distribution range of alien
species and the magnitude of their impacts on native communities, habitats and ecosystem functioning aggregated in a “Biopollution
Level” index (BPL) which ranges from ‘no impact’ (BPL = 0) to ‘massive impact’ (BPL = 4). The assessment performed for nine
Baltic sub-regions revealed that documented ecological impact is only known for 43 alien species out of 119 registered in
the Sea. The highest biopollution (BPL = 3, strong impact) occurs in coastal lagoons, inlets and gulfs, and the moderate biopollution
(BPL = 2)—in the open sea areas. The methodology was also used to classify species into alien (BPL = 0) versus ‘impacting’
species (BPL > 0), which can be divided into ‘potentially invasive’ (BPL = 1) and ‘invasive’ (BPL > 1) ones. No clear correlation
between the number of established alien and impacting species was found in the sub-regions of the Baltic Sea. The methodology,
although requiring a substantial research effort, proved to be useful for interregional comparisons and evaluating the bioinvasion
effects of individual alien species. 相似文献
13.
Abstract. We studied tree regeneration, a key process for the existence of urban woodlands. We hypothesized that, besides the usual biological factors, anthropogenic ones (fragmentation, wear, pollution etc.) determine the regeneration success of tree species in urban woodlands. To test this hypothesis, within an observational setting, we collected data from 30 urban woodlands in the cities of Helsinki and Vantaa, Finland. We defined the number of living saplings (30–200 cm in height) as an indicator of regeneration success and used regression analysis to test different factors as independent variables. The results showed that different tree species responded differently to urban pressure. The regeneration of Picea abies decreased with increasing fragmentation of the forest landscape, whereas for the other most common (deciduous) species, regeneration increased. Wear, measured as total path area per study site, had a negative effect on regeneration success. An a posteriori examination of the data suggested that coarse woody debris might promote regeneration. We conclude that, although tree regeneration in general is not threatened in urban woodlands in the area we studied, the species composition may gradually change. We discuss some management implications for counteracting the urban pressures on tree regeneration. 相似文献
14.
Background, aim and scope The interest in the use of biomass as a renewable energy resource has rapidly grown over the past few years. In Singapore,
biomass resources are mostly from waste wood. This article presents a few technological options, namely carbonization, for
the conversion of woody biomass into a solid fuel, charcoal.
Materials and methods In the first stage, a life cycle assessment (LCA) ‘gate-to-gate’ system was developed for a conventional carbonizer system,
a modern carbonizer from Japan, and a proposed four-stage partial furnace carbonizer from Tunisia. The potential environmental
impacts were generated for global warming potential, acidification, human toxicity and photochemical oxidant potential. Based
on the first set of results, the second LCA investigation was carried out comparing the selected carbonizer from Japan and
an existing incinerator in Singapore. The second LCA adopted a unique approach combining social costs of pollution with the
economic factors of the two biomass conversion technologies.
Results The carbonizer from Japan resulted in approximately 85% less greenhouse gases than the conventional carbonization system and
54% less than the proposed four-stage carbonizer from Tunisia. In terms of acidification and human toxicity, the carbonizers
from Japan and Tunisia display nearly similar results—both were considerably lower than the conventional carbonizer. For photochemical
oxidant potential, very minimal emissions are generated from the four-stage carbonizer and nearly zero impact is realized
for the carbonization technology from Japan.
Discussion From the first set of LCA results, the Japanese carbonizer is favored in terms of its environmental results. The highest environmental
impacts from the conventional carbonizer were due to large and uncontrolled emissions of acidic gases, greenhouse gases (particularly
CO 2 and CH 4), particulates, and non-methane volatile organic compounds from both fugitive sources and energy requirements. The second
LCA addressed the performance of the carbonizer from Japan against an existing incinerator in terms of environmental as well
as cost performances. This unique approach translated pollution emissions into monetary costs to highlight the impacts of
social health.
Conclusions For the first LCA, the accumulated impacts from the Japanese carbonizer proved to display significantly lower environmental
impacts, especially for global warming potential. The overall environmental performance of the four-stage carbonizer from
Tunisia ranked slightly lower than the one from Japan and much higher than the conventional carbonizer. The second LCA results
displayed a noteworthy improvement of 90% for human health from the modern Japanese carbonizer technology—when compared against
conventional incinerators. Without considering health issues or social costs, the total value per ton of wood treated is nearly
similar for both incinerator and carbonizer.
Recommendations and perspectives The interest in biomass as raw material for producing energy has emerged rapidly in many countries. However, careful analysis
and comparison of technologies are necessary to ensure favorable environmental outcomes. A full life cycle study, along with
costs and the impact of pollution on society, should be performed before any large-scale biomass conversion technology is
implemented. LCA can be applied to quantify and verify the overall environmental performance of a particular technology of
interest as well as further explore the proposed technology in terms of costs and social implications. 相似文献
15.
Background, aim and scope Renewable energy sources nowadays constitute an increasingly important issue in our society, basically because of the need
for alternative sources of energy to fossil fuels that are free of CO 2 emissions and pollution and also because of other problems such as the diminution of the reserves of these fossil fuels,
their increasing prices and the economic dependence of non-producers countries on those that produce fossil fuels. One of
the renewable energy sources that has experienced a bigger growth over the last years is wind power, with the introduction
of new wind farms all over the world and the new advances in wind power technology. Wind power produces electrical energy
from the kinetic energy of the wind without producing any pollution or emissions during the conversion process. Although wind
power does not produce pollution or emissions during operation, it should be considered that there is an environmental impact
due to the manufacturing process of the wind turbine and the disposal process at the end of the wind turbine life cycle, and
this environmental impact should be quantified in order to compare the effects of the production of energy and to analyse
the possibilities of improvement of the process from that point of view. Thus, the aim of this study is to analyse the environmental
impact of wind energy technology, considering the whole life cycle of the wind power system, by means of the application of
the ISO 14040 standard [ISO ( 1998) ISO 14040. Environmental management—life cycle assessment—principles and framework. International Standard Organization,
Geneva, Switzerland], which allows quantification of the overall impact of a wind turbine and each of its component parts
using a Life Cycle Assessment (LCA) study.
Materials and methods The procedures, details, and results obtained are based on the application of the existing international standards of LCA.
In addition, environmental details and indications of materials and energy consumption provided by the various companies related
to the production of the component parts are certified by the application of the environmental management system ISO 14001
[ISO ( 2004) ISO 14001 Environmental management systems—requirements with guidance for use. International Standard Organization, Geneva,
Switzerland]. A wind turbine is analysed during all the phases of its life cycle, from cradle to grave, by applying this methodology,
taking into account all the processes related to the wind turbine: the production of its main components (through the incorporation
of cut-off criteria), the transport to the wind farm, the subsequent installation, the start-up, the maintenance and the final
dismantling and stripping down into waste materials and their treatment. The study has been developed in accordance with the
ISO 14044 standard [ISO ( 2006) ISO 14044: Environmental management—life cycle assessment—requirements and guidelines. International Standard Organization,
Geneva, Switzerland] currently in force.
Results The application of LCA, according to the corresponding international standards, has made it possible to determine and quantify
the environmental impact associated with a wind turbine. On the basis of this data, the final environmental effect of the
wind turbine after a lifespan of 20 years and its subsequent decommissioning have been studied. The environmental advantages
of the generation of electricity using wind energy, that is, the reduction in emissions and contamination due to the use of
a clean energy source, have also been evaluated.
Discussion This study concludes that the environmental pollution resulting from all the phases of the wind turbine (manufacture, start-up,
use, and dismantling) during the whole of its lifetime is recovered in less than 1 year.
Conclusions From the developed LCA model, the important levels of contamination of certain materials can be obtained, for instance, the
prepreg (a composite made by a mixture of epoxy resin and fibreglass). Furthermore, it has been concluded that it is possible
to reduce the environmental effects of manufacturing and recycling processes of wind turbines and their components.
Recommendations and perspectives In order to achieve this goal in a fast and effective way, it is essential to enlist the cooperation of the different manufacturers. 相似文献
16.
The GLOBIO3 model has been developed to assess human-induced changes in biodiversity, in the past, present, and future at
regional and global scales. The model is built on simple cause–effect relationships between environmental drivers and biodiversity
impacts, based on state-of-the-art knowledge. The mean abundance of original species relative to their abundance in undisturbed
ecosystems (MSA) is used as the indicator for biodiversity. Changes in drivers are derived from the IMAGE 2.4 model. Drivers
considered are land-cover change, land-use intensity, fragmentation, climate change, atmospheric nitrogen deposition, and
infrastructure development. GLOBIO3 addresses (i) the impacts of environmental drivers on MSA and their relative importance;
(ii) expected trends under various future scenarios; and (iii) the likely effects of various policy response options. GLOBIO3
has been used successfully in several integrated regional and global assessments. Three different global-scale policy options
have been evaluated on their potential to reduce MSA loss. These options are: climate-change mitigation through expanded use
of bio-energy, an increase in plantation forestry, and an increase in protected areas. We conclude that MSA loss is likely
to continue during the coming decades. Plantation forestry may help to reduce the rate of loss, whereas climate-change mitigation
through the extensive use of bioenergy crops will, in fact, increase this rate of loss. The protection of 20% of all large
ecosystems leads to a small reduction in the rate of loss, provided that protection is effective and that currently degraded
protected areas are restored.
Author Contributions RA—Writing, study design, data analyses; MvO—Writing, research; LM— Writing, data analyses; CN—Contribution to method; MB—Research,
data analyses; BtB—Contribution to method. 相似文献
17.
We present an analysis of direct land use change (dLUC) resulting from the conversion of semiarid woodlands in Brazil and India to Jatropha curcas, a perennial biofuel crop. The sites examined include prosopis woodlands, managed for woodfuel production under periodic coppicing, in southern India, and unmanaged caatinga woodlands in the Brazilian state of Minas Gerais. The jatropha plantations under consideration include pruned and unpruned stands and ranged from 2 to 4 years of age. Stocks of carbon in aboveground (AG) pools, including woody biomass, coarse debris, leaf litter, and herbaceous matter, as well as soil organic carbon (SOC) were evaluated. The jatropha plantations store 8–10 tons of carbon per hectare (t C ha ?1) in AG biomass and litter when managed with regular pruning in both India and Brazil. Unpruned trees, only examined in Brazil, store less biomass (and carbon), accumulating just 3 t C ha ?1 in AG pools. The two woodlands that were replaced with jatropha show substantial differences in carbon pools: prosopis contains ~11 t C ha ?1 in AG stocks of carbon, which was very close to the jatropha stand which replaced it. In contrast, caatinga stores ~35 t C ha ?1 in AG biomass. Moreover, no change in SOC was detected in land that was converted from Prosopis to jatropha. As a result, there is no detectable change in AG carbon stocks at the sites in South India where jatropha replaced prosopis woodlands. In contrast, large losses of AG carbon were detected in Central Brazil where jatropha replaced native caatinga woodlands. These losses represent a carbon debt that would take 10–20 years to repay. 相似文献
18.
The New Forest is one of the most visited regions of Britain. It has recently been designated a National Park in recognition
of its unique wood pasture ecosystems, a traditional land-use system, its magnificent scenery and recreational potential,
and its biodiversity importance. The Forest’s highly prized Ancient and Ornamental (A&O) woodlands are a result of complex
interactions among human activities of several kinds and the ecology of the dominant species–beech and oak—under the climate
conditions of the last one to two millennia. Major changes in management practices over the 20th century, combined with the
historical imprint of previous centuries of use, have set the A&O woodlands on a trajectory that means their nature and appearance
will inevitably change over the coming decades. When the potential stresses that will be imposed by 21st century climate change
are also considered, it will be challenging to find a management strategy to maintain A&O woodlands in their present form.
Beech, which owes its current dominance largely to human disturbances of the woodland ecosystem, will be particularly stressed
under future conditions. Future conservation policies, and hence management strategies, must be flexible as to the species
composition and structure of future woodlands. However, the wide range of users and their different values add further complexity
to forest management, and managers must also focus on issues of public perception. For example visitors idealize current landscapes,
and this exerts a pressure to maintain the status quo as far as appearance is concerned that will be hard to achieve in practice.
Management strategies will be greatly constrained unless conflicts about values and uses are resolved. 相似文献
19.
The potential long‐term influences of mesobrowsers versus those of savannah elephants on woodland dynamics have not been explored. This may be a critical omission especially in southern African savannahs, where efforts to preserve existing woodlands are typically directed at elephant management. We describe a simple browse–browser model, parameterized from an extensive review of the literature and our own data, including quantitative assessment of impala impact, from the study site, iMfolozi Park, South Africa. As there is a paucity of species‐specific demographic data on savannah woody species, we modelled, in a novel approach, functional groups of plant species typical of Acacia woodlands. Outputs suggest that over the long term (100 years), low‐to‐moderate densities of impala will have a similar impact on woodland structure, in terms of density of adult trees, as low‐to‐moderate densities of elephant. Further, the outputs highlight the apparently strong synergistic effect impala and elephant impacts combined have on woodland dynamics, suggesting that reduction or removal of either impala or elephant will radically reduce long‐term destruction of savannah woodlands. Recorded changes in adult tree numbers in iMfolozi broadly supported the model's outputs. 相似文献
20.
Background, aim, and scope Composting is a viable technology to treat the organic fraction of municipal solid waste (OFMSW) because it stabilizes biodegradable
organic matter and contributes to reduce the quantity of municipal solid waste to be incinerated or land-filled. However,
the composting process generates environmental impacts such as atmospheric emissions and resources consumption that should
be studied. This work presents the inventory data and the study of the environmental impact of two real composting plants
using different technologies, tunnels (CT) and confined windrows (CCW).
Materials and methods Inventory data of the two composting facilities studied were obtained from field measurements and from plant managers. Next,
life cycle assessment (LCA) methodology was used to calculate the environmental impacts. Composting facilities were located
in Catalonia (Spain) and were evaluated during 2007. Both studied plants treat source separated organic fraction of municipal
solid waste. In both installations the analysis includes environmental impact from fuel, water, and electricity consumption
and the main gaseous emissions from the composting process itself (ammonia and volatile organic compounds).
Results and discussion Inventory analysis permitted the calculation of different ratios corresponding to resources consumption or plant performance
and process yield with respect to 1 t of OFMSW. Among them, it can be highlighted that in both studied plants total energy
consumption necessary to treat the OFMSW and transform it into compost was between 130 and 160 kWh/t OFMSW. Environmental
impact was evaluated in terms of global warming potential (around 60 kg CO 2/t OFMSW for both plants), acidification potential (7.13 and 3.69 kg SO 2 eq/t OFMSW for CT and CCW plant respectively), photochemical oxidation potential (0.1 and 3.11 kg C 2H 4 eq/t OFMSW for CT and CCW plant, respectively), eutrophication (1.51 and 0.77 kg /t OFMSW for CT and CCW plant, respectively), human toxicity (around 15 kg 1,4-DB eq/t OFMSW for both plants) and ozone layer
depletion (1.66 × 10 −5 and 2.77 × 10 −5 kg CFC −11 eq/t OFMSW for CT and CCW plant, respectively).
Conclusions This work reflects that the life cycle perspective is a useful tool to analyze a composting process since it permits the comparison
among different technologies. According to our results total energy consumption required for composting OFMSW is dependent
on the technology used (ranging from 130 to 160 kWh/t OFMSW) as water consumption is (from 0.02 to 0.33 m 3 of water/t OFMSW). Gaseous emissions from the composting process represent the main contribution to eutrophication, acidification
and photochemical oxidation potentials, while those contributions related to energy consumption are the principal responsible
for global warming.
Recommendations and perspectives This work provides the evaluation of environmental impacts of two composting technologies that can be useful for its application
to composting plants with similar characteristics. In addition, this study can also be part of future works to compare composting
with other OFMSW treatments from a LCA perspective. Likewise, the results can be used for the elaboration of a greenhouse
gasses emissions inventory in Catalonia and Spain. 相似文献
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