Impact caps: why population,affluence and technology strategies should be abandoned

This paper classifies strategies to reduce environmental impact according to the terms of the I = PAT formula. Policies limiting resource depletion and pollution (Impact) – by heavily taxing resources or rationing them on a country basis – are thus called ‘direct’ or ‘left-side’ strategies. Other policies to achieve the environmental goal of lowering Impact strive to limit Population and Affluence, or to use Technology to lower the ratio of resource inputs to goods-and-services outputs. Next it is shown that lowering any of these ‘right-side’ factors causes or at least enables the other two to rise or ‘rebound’. This has two consequences: 1) Since I = PAT does not express these interdependencies on the right side, it is more accurately written I = f(P,A,T); and 2) Success in lowering any of the right-side factors does not necessarily lower Impact. Rationing or Pigouvian taxation of resources or pollution, on the other hand, necessarily lower impact and are therefore preferable to population, consumption and technological environmental strategies. Finally, lifestyle and technology changes towards more sufficiency and efficiency would follow the caps as consumers and producers work to retain the greatest amount of welfare within the limits given.     

Total Factor Productivity Change in the New England Groundfish Fishery: 1964–1993

We develop estimates of total factor productivity (TFP) change in the New England groundfish fishery from 1964 to 1993, using a procedure similar to Squires' (1992, Rand J. Econom.23(2), 221–236) method, which extends standard TFP measurement by including the effect of fluctuations in stock abundance. The results indicate that TFP increased on average by 4.4% per year from 1964 to 1993. A higher average rate of increase occurred between 1964 and 1982, possibly due to new technologies (e.g., fishfinders). TFP declined at 0.33% annually from 1983 to 1993 due to stringent output and effort control measures.     

低碳高能,骑车出行没烦恼

<正>下午5点,一场大雨不期而至。史蒂夫站在窗前,心里不免有些失望,因为不能骑车回家了。史蒂夫是个不折不扣的骑行达人。在北京住了10年,换了4辆自行车。他的上一辆自行车报废之前,里程记录仪上留下的数字是3年18844公里,相当于绕二环576圈。10年间,从家门口的胡同开始,史蒂夫骑车转遍了鼓楼、故宫、工体、国贸和香山……从十三陵到南海子,从门头沟到通州,最后他甚至把车骑到了天津。可以这么说,只要是骑车能到达的地方,史蒂夫绝不选     

Spatial and temporal dynamics at manakin leks: reconciling lek traditionality with male turnover

Leks, display grounds where males congregate and females visit to copulate, are typically traditional in location, despite often high turnover of individual males. How leks can persist in face of male turnover is not well understood, in part due to a lack of detailed field data allowing for a clear understanding of lek dynamics. We followed the fate of individual males at 11 to 15 leks of the blue-crowned manakin Lepidothrix coronata across four breeding seasons to gain insights on how leks are formed and changed in space and time. Between years, leks were traditional in location despite changes in territory ownership due to male disappearance and recruitment. New males were equally likely to recruit by taking over existing territories or by establishing new territories. Recruitment was influenced by age, as recruits were more likely to be adults than subadults. Lek size did not affect the probabilities of a male recruiting or persisting at a territory, and vocalization rate, a correlate of mating success in this population, did not affect male persistence. We used our field data to model changes in lek size and composition over longer periods of time (100 years) to understand how lek traditionality can be reconciled with high male turnover. Our simulations showed that leks in our population rapidly stabilize in size despite changes in territory ownership and that rates of male recruitment and disappearance compensate each other, such that leks have the potential to persist for several decades after the original males have disappeared from them.     

PRINCIPLES FOR INTERNATIONAL GROUND-WATER LAW (II)

This is the second part of a paper outlining some principles applicable to the development of international law in the sub-sector of ground-water resources. In the first part of the paper, in the previous issue of the Forum , national ground-water laws were investigated to examine their suitability for adaptation at the international level. This part of the paper is devoted to reviewing the interjurisdictional experience among federated states and among independent states. It also draws the general conclusion of the entire paper.     

Evaluation of an urban NMHC emission inventory by measurements and impact on CTM results

This paper presents an evaluation of the consistency of an urban state-of-the-art hydrocarbon (HC) emission inventory. The evaluation was conducted through the comparison of this inventory with hourly HC measurements during two summer months in the centre of Marseille, on the Mediterranean French coast. Factors of under or overestimation could be calculated for each compound on the basis of a systematic HC to HC ratio analysis. These results, associated with a deep analysis of the speciation profiles, show that most of the common and highly concentrated hydrocarbons (such as butanes) are too much predominant in the emission speciation, while the heavy and less common species (branched alkanes, substituted aromatics) are under-represented in the inventory. The urban diffuse sources appear here as one critical point of the inventories. The disagreements were shown to have a strong incidence on the representation of the air mass reactivity. In a last step, the identified uncertainties in emissions were implemented in an air-quality model for sensitivity studies. It was shown that the observed biases in the inventory could affect the regional ozone production, with a probable impact on ozone peaks of 2–10 ppbv over the area.     

A New Method for the Rapid Determination of Volatile Organic Compound Breakthrough Times for a Sorbent at Concentrations Relevant to Indoor Air Quality

Abstract

The use of sorbents has been proposed to remove volatile organic compounds (VOCs) present in ambient air at concentrations in the parts-per-billion (ppb) range, which is typical of indoor air quality applications. Sorbent materials, such as granular activated carbon and molecular sieves, are used to remove VOCs from gas streams in industrial applications, where VOC concentrations are typically in the parts-per-million range. A method for evaluating the VOC removal performance of sorbent materials using toluene concentrations in the ppb range is described. Breakthrough times for toluene at concentrations from 2 to 7500 ppb are presented for a hydrophobic molecular sieve at 25% relative humidity. By increasing the ratio of challenge gas flow rate to the mass of the sorbent bed and decreasing both the mass of sorbent in the bed and the sorbent particle size, this method reduces the required experimental times by a factor of up to several hundred compared with the proposed American Society of Heating, Refrigerating, and Air-Conditioning Engineers method, ASHRAE 145P, making sorbent performance evaluation for ppb-range VOC removal more convenient. The method can be applied to screen sorbent materials for application in the removal of VOCs from indoor air.