改变生产与消费方式:已经取得的进展与存在的挑战

在贫困不断减少以及经济持续增长的情况下,生产与消费方式必然会由不可持续型向可持续型转变.由于这会使人们显著改变思想观念与行为方式,因此需要解决生产者与消费者责任问题.清洁生产是企业社会责任的核心.目前UNEP已收到多项建议,其中包括发展清洁生产与可持续消费指标以及增进多方合作性举措.     

Influence of organic ley–arable management and afforestation in sandy loam to clay loam soils on fluxes of N2O and CH4 in Scotland

Assessment of the sustainability of alternatives to conventional uses of agricultural land, viz. organic systems and afforestation should include consideration of any effects on trace gas budgets. Nitrous oxide (N₂O) and methane (CH₄) fluxes and controlling soil properties were measured in an organic ley–arable rotation in north-east Scotland on a sandy loam. N₂O fluxes were monitored in the ley and arable phases and in organic permanent grass (Lolium perenne) located nearby throughout the 3-year phase duration. Gas fluxes in woodland that had been converted from arable for 1 or 6 years were also measured in both north-east and south-east Scotland on sandy loam to clay loam soils. The climate is maritime and variable with annual rainfall between 800 and 900 mm. Within the organic rotation, differences in N₂O fluxes between the ley and arable phases were less marked than in conventional agriculture. Although this was mainly because grassland emissions were low, some losses from the arable component were also relatively high. Seasonal rainfall had a major influence on cumulative emissions of N₂O, including the first year after conversion from ley to arable. In the short term, changing land use from arable to woodland increased CH₄ oxidation rates and decreased N₂O emissions, though both these rates were also influenced by seasonal weather. Afforestation of agricultural land appears to be more beneficial to trace gas exchange than conversion to organic production.     

Seasonal and spatial variation of solvent extractable organic compounds in fine suspended particulate matter in Hong Kong

The results of a 12-month study of more than 100 solvent extractable organic compounds (SEOC) in particulate matter (PM) less than or equal to 2.5 microm (PM2.5) collected at three air monitoring stations located at roadside, urban, and rural sites in Hong Kong are reported. The total yield of SEOC that accounts for approximately 8-18% of organic carbon (OC) determined by a thermal optical transmittance method was 125-2060 ng/m3, which included 14.6-128 ng/m3 resolved aliphatic hydrocarbons, 39.4-1380 ng/m3 unresolved complex mixtures, 0.6-17.2 ng/m3 polycyclic aromatic hydrocarbons, 41.6-520 ng/m3 fatty acids, and < 0.1-12.1 ng/m3 alkanols. Distinct seasonal variations (summer/winter differences) were observed with higher concentrations of the total and each class of SEOC in the winter and lower concentrations in the summer. Spatial variations are also obvious, with the roadside samples having the highest concentrations of SEOC and the rural samples having the lowest concentrations in all seasons. Characteristic ratios of petroleum hydrocarbons, such as carbon preference index, unresolved to resolved components, and carbon number with maximum concentration, suggest that PM2.5 carbon in Hong Kong originates from both biogenic and anthropogenic sources. The proportion of SEOC in PM2.5 from anthropogenic sources is estimated.     

Removal process estimation of population size for a population with a known sex ratio

A removal model for estimating population size which uses the known population sex ratio is studied. A maximum likelihood estimate and an optimal martingale estimate of the population size are proposed. Their standard errors and large sample properties are obtained. Simulation studies are reported, and the performance of the proposed estimators are compared with the standard maximum likelihood estimator which ignores the sex ratio information. An example on a capture study of deer mice is given.     

Assessment of prey vulnerability through analysis of wolf movements and kill sites.

Within predator-prey systems behavior can heavily influence spatial dynamics, and accordingly, the theoretical study of how spatial dynamics relate to stability within these systems has a rich history. However, our understanding of these behaviors in large mammalian systems is poorly developed. To address the relationship between predator selection patterns, prey density, and prey vulnerability, we quantified selection patterns for two fine-scale behaviors of a recovering wolf (Canis lupus) population in Yellowstone National Park, Wyoming, USA. Wolf spatial data were collected between November and May from 1998-1999 until 2001-2002. Over four winters, 244 aerial locations, 522 ground-based telemetry locations, 1287 km of movement data from snow tracking, and the locations of 279 wolf kill sites were recorded. There was evidence that elk (Cervus elaphus) and bison (Bison bison) densities had a weak effect on the sites where wolves traveled and made kills. Wolf movements showed a strong selection for geothermal areas, meadows, and areas near various types of habitat edges. Proximity to edge and habitat class also had a strong influence on the locations where elk were most vulnerable to predation. There was little evidence that wolf kill sites differed from the places where wolves traveled, indicating that elk vulnerability influenced where wolves selected to travel. Our results indicate that elk are more vulnerable to wolves under certain conditions and that wolves are capable of selecting for these conditions. As such, vulnerability plays a central role in predator-prey behavioral games and can potentially impact the systems to which they relate.     

Fueling global fishing fleets

Over the course of the 20th century, fossil fuels became the dominant energy input to most of the world's fisheries. Although various analyses have quantified fuel inputs to individual fisheries, to date, no attempt has been made to quantify the global scale and to map the distribution of fuel consumed by fisheries. By integrating data representing more than 250 fisheries from around the world with spatially resolved catch statistics for 2000, we calculate that globally, fisheries burned almost 50 billion L of fuel in the process of landing just over 80 million t of marine fish and invertebrates for an average rate of 620 L t(-1). Consequently, fisheries account for about 1.2% of global oil consumption, an amount equivalent to that burned by the Netherlands, the 18th-ranked oil consuming country globally, and directly emit more than 130 million t of CO2 into the atmosphere. From an efficiency perspective, the energy content of the fuel burned by global fisheries is 12.5 times greater than the edible-protein energy content of the resulting catch.     

Air quality measurements from the Fresno Supersite

The Fresno Supersite intends to 1) evaluate non-routine monitoring methods, establishing their comparability with existing methods and their applicability to air quality planning, exposure assessment, and health effects studies; 2) provide a better understanding of aerosol characteristics, behavior, and sources to assist regulatory agencies in developing standards and strategies that protect public health; and 3) support studies that evaluate relationships between aerosol properties, co-factors, and observed health end-points. Supersite observables include in-situ, continuous, short-duration measurements of 1) PM2.5, PM10, and coarse (PM10 minus PM2.5) mass; 2) PM2.5 SO4(-2), NO3-, carbon, light absorption, and light extinction; 3) numbers of particles in discrete size bins ranging from 0.01 to approximately 10 microns; 4) criteria pollutant gases (O3, CO, NOx); 5) reactive gases (NO2, NOy, HNO3, peroxyacetyl nitrate [PAN], NH3); and 6) single particle characterization by time-of-flight mass spectrometry. Field sampling and laboratory analysis are applied for gaseous and particulate organic compounds (light hydrocarbons, heavy hydrocarbons, carbonyls, polycyclic aromatic hydrocarbons [PAH], and other semi-volatiles), and PM2.5 mass, elements, ions, and carbon. Observables common to other Supersites are 1) daily PM2.5 24-hr average mass with Federal Reference Method (FRM) samplers; 2) continuous hourly and 5-min average PM2.5 and PM10 mass with beta attenuation monitors (BAM) and tapered element oscillating microbalances (TEOM); 3) PM2.5 chemical speciation with a U.S. Environmental Protection Agency (EPA) speciation monitor and protocol; 4) coarse particle mass by dichotomous sampler and difference between PM10 and PM2.5 BAM and TEOM measurements; 5) coarse particle chemical composition; and 6) high sensitivity and time resolution scalar and vector wind speed, wind direction, temperature, relative humidity, barometric pressure, and solar radiation. The Fresno Supersite is coordinated with health and toxicological studies that will use these data in establishing relationships with asthma, other respiratory disease, and cardiovascular changes in human and animal subjects.     

Analysis of PM2.5 and PM10 in the atmosphere of Mexico City during 2000-2002

During the last 10 years, high atmospheric concentrations of airborne particles recorded in the Mexico City metropolitan area have caused concern because of their potential harmful effects on human health. Four monitoring campaigns have been carried out in the Mexico City metropolitan area during 2000-2002 at three sites: (1) Xalostoc, located in an industrial region; (2) La Merced, located in a commercial area; and (3) Pedregal, located in a residential area. Results of gravimetric and chemical analyses of 330 samples of particulate matter (PM) with an aerodynamic diameter less than 2.5 microm (PM2.5) and PM with an aerodynamic diameter less than 10 microm (PM10) indicate that (1) PM2.5/PM10 average ratios were 0.42, 0.46, and 0.52 for Xalostoc, La Merced, and Pedregal, respectively; (2) the highest PM2.5 and PM10 concentrations were found at the industrial site; (3) PM2.5 and PM10 concentrations were lower at nighttime; (4) PM2.5 and PM10 spatial averages concentrations were 35 and 76 microg/m3, respectively; and (5) when the PM2.5 standard was exceeded, nitrate, sulfate, ammonium, organic carbon, and elemental carbon concentrations were high. Twenty-four hour averaged PM2.5 concentrations in Mexico City and Sao Paulo were similar to those recorded in the 1980s in Los Angeles. PM10 concentrations were comparable in Sao Paulo and Mexico City but 3-fold lower than those found in Santiago.