Resource depletion

Sometimes LCA stops at the end of the inventory step. There may be two explanations for this. One is that all emissions and resource depletion improve, when compared to a reference alternative. Tu this case an impact assessment is not required. 

An indicator result could, for instance, be compared to the total indicator value in an area, or to the average indicator value per inhabitant per year. Other common methods are to compare with national reduction targets and with damage costs from emissions and resource depletion. Sometimes these are weighed across impact categories made by expert panels. However, some studies using this technique would not meet the requirement of transparency for the weighting process set by ISO. 

Using the factors from Table 15.2, all the methods recommend the electrostatic precipitator (Table 15.4). The priorities obtained by different methods do not always agree. The EPS method is more sensitive to resource depletion than the other methods. 

Higher incomes, higher automobile ownership, and a decline in the population and workplaces that can be sciwcd by mass transit has lead to the declining mass transit demand. Criticism of this shift toward the private automobile comes mainly because the individual driver receives the short-term benefits (privacy, comfort, speed, and convenience), while the negative social consequences (air pollution, traffic jams, and resource depletion) are shared by all. Moreover, if people drove less, and drove more-fuel-efficient vehicles, the positive national goal of less dependence on imported oil would be achieved. 

Morphological plasticity and cellular acclimation When plants are exposed to stress as a consequence of resource depletion or climatic fluctuation, many different responses are possible depending upon the species and the nature and severity of the stress. However, as Bradshaw (1965) recognised, stress responses can be classified into two basic types, one of which is morphological and the other physiological. One of the major uses of plant strategy theory is to provide a basis for predicting which of the two mechanisms is likely to be operative in particular species, populations and situations. 

An even more streamlined approach scores each stage of the life cycle for impact on a number of environmental indicators. Typical indicators include resource depletion, global warming potential, smog production, acidification, eutrophication, toxic waste production and biodiversity impact. Impact is estimated using a simple numerical scale. The completed matrix is used to focus attention on areas for improvement. 

Furthermore, some studies (e.g., [15-17]) show that some environmental effects associated with emissions and resource depletion can be expressed based on physical principles in terms of an exergy-based indicator. It may be possible to generalize this indicator to cover a comprehensive range of environmental effects, and such research is ongoing. 

As focus in this chapter is on additives/chemicals and emissions, the impact category on resource consumption is not included. Results regarding resource depletion may be found in the case study report [8],... 

Natural gas extraction Natural gas [resource] Resource depletion 2 6 5 6... 

Ethylene production Crude oil [resource] Resource depletion 1 2 2 2... 

Environmental stress (e.g. natural resource depletion, etc.) is one of the elements having an influence on security. The relationship is so complex and interrelated. 

Thirgood, J. V. 1981. Man and the Mediterranean Forest A History of Resource Depletion. Academic Press, London, New York, 194 p. 

Scarce resource depletion No full depletion replacement by renewables... 

Economy/profit Scarce resource depletion Drinking water resource depletion Fossil fuel depletion External (future) cost low Capital expenditure Operational cost Profitable over total lifecycle... 

Economy/profit Scarce resource depletion Drinking water resource depletion Fossil fuel depletion External (future) cost low Lower capital expenditure Lower operational cost Profitable over total lifecycle To be assessed for each case Not identified yet Yes improvement factor > 4 Yes Yes factor > 4 Yes factor > 4 Likely... 

Scarce Resource Depletion. For any new technology, the longterm and worldwide effects on scarce-resource consumption should be assessed over its entire lifecycle. For instance, even minute amounts of rare earth metals per... 

Hence, instead of considering the renewable versus the nonrenewable resources in a process, it is preferred to quantitatively combine the consumption rate ( ra/ConSumption)/ the regeneration rate ((t>m/production), and the extent of natural reserves (Mreserves) of a resource, as they are known at this time, in a resource depletion time (x) defined as... 

Besides taking into account any gap between the consumption and regeneration rate of a resource, the depletion time relates this gap to the extent of the natural reserves. The depletion time is then a measure for the rate at which the currently known reserves of a resource are being depleted. For example, a depletion time of 100 years means that currently 1% of the known reserves is being depleted yearly likewise, a depletion time of 1000 years means that yearly 0.1% is being depleted. It should be stressed that the depletion time as defined in Equation 13.13 does not attempt to predict resource depletion in the future it merely indicates how fast a known supply of a resource is currently being depleted. 

This definition means that the depletion time of a resource is time dependent. The consumption rate of a resource may increase over time as a result of increased industrial production, or it may decrease if alternative resources are increasingly being used. Likewise, the regeneration rate may increase when more resources are recycled, and reserves may shrink after prolonged utilization or may expand when new natural deposits are found. In addition, more accurate data may become available, for example, on the extent of currently known reserves or on the natural formation rates of certain deposits. In any case, the depletion time x is variable, and it reflects the rate of resource depletion only in the present situation. 

The reference time x0 in Equation 13.14 represents the resource depletion time at which the abundance factor a, is at the value of exactly one half (i.e., 50%). This reference time x0 must be given an appropriate value at which the factors a, adequately reflect the differences in the abundance of real resources. For example, a reference time x0 of 1000 years will give fossil fuels abundance factors roughly ranging from 0.1 to 0.5, while sunlight, probably available for billions of years, will have an abundance factor approaching unity. 

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