Climatic Implications of Revised IPCC Emissions Scenarios, the Kyoto Protocol and Quantification of Uncertainties

In December 1997, the United Nations Framework Convention on Climate Change (FCCC) adopted the Kyoto Protocol. This paper describes a framework that models the climatic implications of this international agreement, using Monte Carlo simulations and the preliminary Intergovernmental Panel on Climate Change emissions scenarios (SRES). Emissions scenarios (including intervention scenarios), climate sensitivity, and terrestrial carbon sink are the key sampled model parameters. This framework gives prior probability distributions to these parameters and, using a simple climate model, posterior distributions of global temperature change are determined for the future. Our exercise showed that the Kyoto Protocol's effectiveness will be mostly dependent upon which SRES world evolves. In some worlds the Protocol decreases the warming considerably but in others it is almost irrelevant. We exemplified this approach with a current FCCC issue, namely “hot air”. This modelling framework provides a probabilistic assessment of climate policies, which can be useful for decision-makers involved in global climate change management. This revised version was published online in July 2006 with corrections to the Cover Date.     

Mapping Economic Returns to Agriculture for Informing Environmental Policy in the Murray–Darling Basin, Australia

We integrate information from several disparate data sources including agricultural statistics and remote sensing to quantify and map the distribution and dynamics of agricultural returns to land and water resources from 1996/1997 to 2000/2001 in the Murray–Darling Basin (MDB), Australia. Total profit to agriculture was estimated at AUD3.86B in 1996/1997 and AUD3.73B in 2000/2001. The mapping reveals a high spatial concentration of economic returns to land and water resources from agriculture. Dryland agriculture covers over 82% of the study area. Irrigated agriculture covers 1.7% of the land area (2000/2001) but returns one third of the total profit to agriculture. We found that around 80% of the profit to agriculture comes from just over 5% of the land area. The results from this regional scale economic mapping can inform regulatory policy and public investments in natural resource management through targeting industries and regions that provide low marginal returns to the natural resource base.     

Evaluating long-term nitrogen- versus phosphorus-based nutrient management of poultry litter

Environmental concerns are driving manure management in many areas from a traditional nitrogen (N) basis toward phosphorus (P)-based nutrient management plans. We investigated how changing nutrient management from an N to a P basis affected crop yields and soil properties in high P soils over a 7-yr period. Three sites were established on farmers' fields, and at each site the same six treatments were applied for 6 or 7 yr. These treatments were (i) no P; (ii) poultry litter applied on an N basis; (iii) inorganic P, equal to the P applied in treatment 2; (iv) poultry litter applied on an estimated annual crop P removal basis; (v) inorganic P, equal to the P applied in treatment iv; and (vi) poultry litter applied once every 2 or 3 yr at a 2- or 3-yr crop removal P rate. All treatments received the same rate of plant-available N. Yields, P balance, soil pH, Mehlich 1 P, and water-soluble P (WSP) were monitored during the experiment. Over the course of the experiment, litter had the beneficial effect of raising soil pH relative to the inorganic treatments. After 7 yr, Mehlich 1 P and WSP were greatest in soils under the N-based treatments, smallest in the no P treatment, and intermediate in the P-based treatments. For example, at the Shenandoah site, Mehlich 1 P decreased by 35 mg kg(-1) under the no P treatment and increased by 36 mg kg(-1) under the inorganic N-based treatment. There were no significant differences between inorganic fertilizer and poultry litter nutrient sources. The results of this study show that soil test P can be decreased in high-P soils over a few years by changing from an N-based to a P-based nutrient management plan or stopping P applications without negatively affecting yields.     

Long-term changes in acidity and DOC in throughfall and soil water in Finnish forests

The main objective of this study was to examine if any detectable trends in dissolved organic carbon (DOC), sulphate (SO₄-S) concentrations and acid neutralizing capacity (ANC) in throughfall (TF) and soil water (SW) could be found during 1990–2010 and to relate them to recent changes in decreased acid deposition. The study was conducted in seven boreal coniferous forest sites: four of which are managed and three unmanaged forests sites. Generally, temporal trend showed a significant decrease in SO₄-S concentrations in bulk precipitation (BP), TF and SW. At some of the sites, there was an increasing tendency in BP and TF in the DOC concentrations. This feature coincides with decreasing SO₄-S concentration, indicating that SO₄-S may be an important driver of DOC release from the canopy. However, a slightly increased temperature, larger senescing needle mass and consequently increased decaying activity in the canopy may partly explain the increasing trend in DOC. In SW, no consistent DOC trend was seen. At some sites, the decreased base cation concentrations mostly account for the decrease in the ANC values in SW and TF.     

Small wonders, big future: the development of environmental nanotechnology

Nanotechnology--the engineering of atomic-scale devices and systems--is set to become one of the major industries of the 21st century. Environmental applications are emerging as a key area of interest. But alongside the benefits, there are concerns that nanotechnologies could bring new risks to the environment and human health. Are nanotechnologies friend or foe? And how can analysts contribute to the debate?     

Cost-Effective Mitigation of Diffuse Pollution: Setting Criteria for River Basin Management at Multiple Locations

A case study of the Yorkshire Derwent (UK) catchment is used to illustrate an integrated approach for assessing the viability of policy options for reducing diffuse nitrate losses to waterbodies. For a range of options, modeling methods for simulating river nitrate levels are combined with techniques for estimating the economic costs to agriculture of modifying those levels. By incorporating spatially explicit data and information on catchment residence times (which may span many decades particularly in areas of groundwater discharge) a method is developed for efficient spatial targeting of measures, for example, to the most at-risk freshwater environments. Combining hydrological and economic findings, the analysis reveals that, in terms of cost-effectiveness, the ranking of options is highly sensitive to both (i) whether or not specific stretches of river within a catchment are regarded as a priority for protection, and (ii) the criterion of nitrate concentration deemed most appropriate as an indicator of the health of the environment. Therefore, given the focus under European legislation upon ecological status of freshwaters, these conclusions highlight the need to improve understanding of mechanistic linkages between the chemical and biological dynamics of aquatic systems.     

Poverty as a determinant of young drivers' fatal crash risks

Problem

U.S. teenaged and young-adult drivers' elevated rates of fatal traffic crash involvement typically are attributed to biological and developmental risk-taking associated with young age. However, young drivers differ from older ones along several sociodemographic dimensions, including higher poverty rates and greater concentration in poorer areas, which may contribute to their risks.

Method

Using Fatality Analysis Reporting System, Census, and Federal Highway Administration data for 1994-2007, bivariate and multivariate regression analyses were conducted of fatal motor-vehicle crash involvements per 100 million miles driven by driver age (16 through 74) and state along with 14 driver-, vehicle-, and state-level variables.

Results

Driver age was not a significant predictor of fatal crash risk once several factors associated with high poverty status (more occupants per vehicle, smaller vehicle size, older vehicle age, lower state per-capita income, lower state population density, more motor-vehicle driving, and lower education levels) were controlled. These risk factors were significantly associated with each other and with higher crash involvement among adult drivers as well.

Summary and Discussion

The strong association between fatal crash risk and environments of poverty as operationalized by substandard vehicle and driving conditions suggests a major overlooked traffic safety factor particularly affecting young drivers.