Near term mitigation policy for global change under uncertainty: Minimizing the expected cost of meeting unknown concentration thresholds

An aggregate integrated assessment model is used to investigate the relative merits of hedging over the near term against the chance that atmospheric concentrations of carbon dioxide will be limited as a matter of global policy. Hedging strategies are evaluated given near term uncertainty about the targeted level of limited concentrationsand the trajectory of future carbon emissions. All uncertainty is resolved in the year 2020, and strategies that minimize the expected discounted value of the long term cost of abatement, including the extra cost of adjusting downstream to meet unexpected concentration limits along unanticipated emission trajectories, are identified. Even with uncertainties that span current wisdom on emission futures and restriction thresholds that run from 550 ppm through 850 ppm, the results offer support for at most modest abatement response over the next several decades to the threat of global change.     

VALIDATION OF A BRIEF SCREENING MEASURE OF ENVIRONMENTAL CHEMICAL SENSITIVITY: THE CHEMICAL ODOR INTOLERANCE INDEX

The development and validation of a brief self-report screening measure of environmental chemical sensitivity, the Chemical Odor Intolerance Index (CII), is described. Subjects included 1734 college students, 192 older adults, and 38 chemically intolerant and multiple chemical sensitivity (MCS) patients. The results of the studies demonstrate that the CII has strong internal stability (Cronbach's alpha ranging from 0.80 to 0.92 across samples), and evidence of factorial, group, convergent, and discriminant validity is reported across diverse samples. In future research, the CII will permit the quantification of self-reported illness from low levels of environmental chemicals as a continuous rather than dichotomous variable. Consequently, the CII will facilitate the ability to compare and standardize subject selection criteria in both preclinical and clinical (i.e. MCS) populations.     

The effects of pathway configuration, landmarks and stress on environmental cognition

The results of this study indicate that manipulations of the pathway grid configuration and landmark placement in a setting cause changes in environmental knowledge. These experimental manipulations were accomplished using a realistic, dynamic simulation technique at the Berkeley Environmental Simulation Laboratory. Measures of environmental knowledge include: memory for incidental information along the simulated urban route, accuracy of route maps, relocation memory for scenes along the route, and questionnaire measures. Data are also presented showing both positive and negative effects of stress from noise on the processes of environmental cognition.     

Substitution and the control of pollution : A comparison of effluent charges and quantity standards under uncertainty

Single-valued price and quantity controls of a polluting activity are compared under uncertainty. The ability to substitute other inputs for the pollutant in the production of a positively valued final good, and the usual discrepancy between the amount of pollution actually consumed and the amount emitted are carefully incorporated. The first is found to influence the degree to which cost fluctuation is reflected in the output of the final good. The second concern alters the region of the benefit function into which output is inserted. Both change the welfare losses associated with random fluctuation in the costs of reducing pollution.     

Urban estuarine systems under stress: Environmental issues facing Louisiana's Lake pontchartrain

Summary Lake Pontchartrain is part of a brackish coastal estuarine system which serves as an important economic and recreational resource for the New Orleans region. Seafood extraction, shell dredging and leisure time activities are the major uses occurring on Lake Pontchartrain. In the past several decades, man has severely altered this system through urbanization, industrial activity, levée construction and subsequent destruction of wetlands surrounding the lake. There is a growing awareness of the environmental crisis facing Lake Pontchartrain, advanced by recent fish kills, detection of toxic chemicals, curtailment of recreational opportunities and the report of dead zones in the lake. This study summarizes a series of international environmental management techniques and examines the utilization of a regional structure for water resources management in the Lake Pontchartrain Basin.Dr. Fritz Wagner is Director and Professor of the School of Urban and Regional Studies at the University of New Orleans and David Hart was a Research Assistant in the same school, and is now employed in a local engineering and planning company.     

Preliminary Studies on Converting Agricultural Waste into Biodegradable Plastics—Part IV: Polysaccharide Containing Natural Materials

Corn distillers’ dry grain, corncob powder, hardwood powder, and sugar beet pulp were separately anionized by oxidation with sodium hypochlorite in aqueous solution. Solid reaction products instantly precipitated upon admixing each of the above-oxidized materials with soy protein isolate. Infrared spectra and differential scanning calorimetry supported the hypothesis that soy protein isolate complexed with all of the above-oxidized polysaccharides. Reaction products with either oxidized corn distillers’ dry grain or oxidized sugar beet pulp provided hard, brittle pellets with tensile strengths as high as 9.5 MPa, suggesting that these materials could be viable as biodegradable plastics.     

Economic valuation of marsh areas for marine production processes

The relationship of natural marsh-estuarine systems to the economic productivity of marine systems is not well understood, at least in any quantitative sense. An approach is developed for relating blue crab economic productivity on Florida's Gulf Coast to marsh availability in the area. Previous efforts have not always applied economic concepts appropriately in attempts at such quantification. The marginal value productivity of marsh is shown to vary with alternative levels of marsh and effort in the fishery. The interaction and subsequent interdependence is shown to be statistically significant. Data availability on marginal response to marsh changes poses a severe obstacle to further progress.     

Passive sampler derived air concentrations of PBDEs along an urban-rural transect: spatial and temporal trends

Passive air samplers consisting of polyurethane foam (PUF) disks housed in chambers were deployed at several sites along a approximately 75 km urban-rural gradient in Toronto and analyzed for polybrominated diphenyl ethers (PBDEs). Samplers were allowed to integrate gas-phase PBDEs over three consecutive seasons starting in the summer of 2000. PBDEs were fairly uniform along the transect with air concentrations in Toronto (10-30 pgm(-3)) about a factor of two greater than at rural sites. Lowest concentrations were observed during the winter and probably associated with reduced inputs from indoor sources of PBDEs and to a preference for PBDEs to partition to the particle-phase at colder temperatures. The composition of PBDEs in the air samples did not differ across the transect or for the different seasons.