Challenges in quantifying biosphere-atmosphere exchange of nitrogen species

Recent research in nitrogen exchange with the atmosphere has separated research communities according to N form. The integrated perspective needed to quantify the net effect of N on greenhouse-gas balance is being addressed by the NitroEurope Integrated Project (NEU). Recent advances have depended on improved methodologies, while ongoing challenges include gas-aerosol interactions, organic nitrogen and N(2) fluxes. The NEU strategy applies a 3-tier Flux Network together with a Manipulation Network of global-change experiments, linked by common protocols to facilitate model application. Substantial progress has been made in modelling N fluxes, especially for N(2)O, NO and bi-directional NH(3) exchange. Landscape analysis represents an emerging challenge to address the spatial interactions between farms, fields, ecosystems, catchments and air dispersion/deposition. European up-scaling of N fluxes is highly uncertain and a key priority is for better data on agricultural practices. Finally, attention is needed to develop N flux verification procedures to assess compliance with international protocols.     

Nuclear power in the 21st century: Challenges and possibilities

The current situation and possible future developments for nuclear power—including fission and fusion processes—is presented. The fission nuclear power continues to be an essential part of the low-carbon electricity generation in the world for decades to come. There are breakthrough possibilities in the development of new generation nuclear reactors where the life-time of the nuclear waste can be reduced to some hundreds of years instead of the present time-scales of hundred thousand of years. Research on the fourth generation reactors is needed for the realisation of this development. For the fast nuclear reactors, a substantial research and development effort is required in many fields—from material sciences to safety demonstration—to attain the envisaged goals. Fusion provides a long-term vision for an efficient energy production. The fusion option for a nuclear reactor for efficient production of electricity has been set out in a focussed European programme including the international project of ITER after which a fusion electricity DEMO reactor is envisaged.     

Occurrence and distribution of trifluralin,ethalfluralin, and pendimethalin in soils used for long-term intensive cotton cultivation in central Greece

In the present study, a soil monitoring program was undertaken in Greek cotton cultivated areas in 2012. Twenty-seven soil samples were collected from the entire Thessaly plain in early summer of 2012, corresponding to approximately three months (current use of pendimethalin), up to one year (for the banned ethalfluralin), and three years (for the also banned trifluralin), after the last dinitroaniline application. Low but not negligible levels of dinitroanilines were detected, ranging from 0.01 to 0.21 μg g^?1 d.w. for trifluralin and 0.01–0.048 μg g^?1 d.w. for pendimethalin, respectively. Trifluralin was the herbicide most frequently detected (44.4%). The high historic application of trifluralin and its high persistence and accumulation potential is in line with the abundance of the detected residues. The present data indicate that soil samples contain extractable residues of banned trifluralin, but based on the comparison of the theoretical PECplateau for trifluralin (0.277 µg g^?1) and the maximum Measured Environmental Concentration, it was concluded that the detected residues should be attributed to previous years’ application. The latter suggested the need for continual monitoring of the dinitroaniline family of pesticides, including the banned substances, aiming thus to an improved environmental profile for agricultural areas.     

Particle concentrations in data centers

Cooling buildings with large airflow rates of outside air when temperatures are favorable is an established energy-saving measure. In data centers, this strategy is not widely used, owing to concerns that it would cause increased indoor levels of particles of outdoor origin, which could damage electronic equipment. However, environmental conditions typical of data centers and the associated potential for equipment failure are not well characterized. This study presents the first published measurements of particle concentrations in operating data centers. Indoor and outdoor particle measurements were taken at eight different sites in northern California for particulate matter 0.3–5.0 μm in diameter. One of the data centers has an energy-efficient design that employs outside air for cooling, while the rest use conventional cooling methods. Ratios of measured particle concentrations in the conventional data centers to the corresponding outside concentrations were significantly lower than those typically found in office or residential buildings. Estimates using a material-balance model match well with empirical results, indicating that the dominant particle sources and losses have been identified. Measurements taken at the more energy-efficient site show nearly an order of magnitude increase in particle concentration when ventilation rates were high. The model indicates that this increase may be even higher when including particles smaller than the monitoring-equipment size limitation. Even with the increases, the measured particle concentrations are still below concentration limits recommended in industry standards.     

Establishing the link between ammonia emission control and measurements of reduced nitrogen concentrations and deposition

In the context of international efforts to reduce the impactsof atmospheric NH₃ and NH₄ ⁺ (collectively, NH_x), it is important to establish the link between NH₃emissions and monitoring of NH_x concentrations and deposition. This is equally relevant to situations where NH₃emissions changes are certain (e.g. due to changed source sectoractivity), as to cases where NH₃ abatement technologies havebeen implemented. Correct interpretation of adequate atmosphericmeasurements is essential, since monitoring data provide the onlymeans to evaluate trends in regional NH₃ emissions.These issues have been reviewed using available measurements and modelling from nine countries. In addition to historic datasets,the analysis here considers countries where NH₃ source sector activity changed (both increases and decreases) and countries where NH₃ abatement policies have been implemented.In The Netherlands an `ammonia gap' was identified between the expected reduction and results of monitoring, and was attributedinitially to ineffectiveness of the abatement measures. The analysis here for a range of countries shows that atmospheric interactions complicate the expected changes, particularly sinceSO₂ emissions have decreased at the same time, while at manysites the few years of available data show substantial inter-annual variation. It is concluded that networks need to beestablished that speciate between NH₃ and aerosol NH₄ ⁺, in addition to providing wet deposition, and sample at sufficient sites for robust regional estimates to be established. Such measurements will be essential to monitor compliance of the international agreements on NH₃ emission abatement.     

Adaptation by Older Individuals Repeatedly Exposed to 0.45 Parts per Million Ozone for Two Hours

To test for an increased reaction to ozone (O₃) in older individuals following an initial exposure, and to test for adaptation and its duration, we exposed 10 men and 6 women (60-89 years old) in an environmental chamber to filtered air and 3 consecutive days of O₃ exposure (0.45 ppm), followed by a fourth O₃ exposure day after a two day hiatus. Subjects alternated 20-min exercise (minute ventilation = 27 L) and rest periods for 2 hours during each exposure. Subjects rated from one to five, 16 possible respiratory/exercise symptoms prior to and following the exposure. Pulmonary function tests were performed before, and during each rest period and following the exposure. Metabolic measurements were obtained during each exercise period. No significant changes in any symptom question occurred, in spite of a threefold increase in the total number of reported symptoms during O₃ exposure. Small but significant pre-to-post decrements on the first and second O₃ days in forced vital capacity (FVC—111 and 104 mL), forced expiratory volume in 1 (FEV₁—171 and 164 mL) and 3 seconds (FEV₃—185 and 172 mL) occurred without concomitant changes in any flow parameter of the forced expiratory maneuver. No differences in the group mean response in FVC, FEV₁, OR FEV₃ on the third or fourth day of O₃ exposure and the filtered air exposure were found. The observed changes were due to significant physiological changes in eight of the subjects. Unlike young subjects, no evidence of an increased pulmonary function response to a second consecutive O₃ exposure was observed. Changes in small airway response to O₃ (below 75 percent of FVC) without irritant receptor activation, would explain the observed pattern of response.     

Development planning in Mexico: Case study of an oil-rich economy

The authors identify problems of political, economic and social development in Mexico, which has now become a net oil exporter. Aspects of Mexican society are analysed - possession of resources, population growth, agricultural and industrial sectors of the economy and development policy. The political and economic components of social change and policy limitations are considered. It is clear that the severity of Mexico's development problems present serious issues for the current administration.     

Do children play fair with mother nature? Understanding children’s judgments of environmentally harmful actions

The current study asks how young children judge behaviors that harm the environment as compared to moral transgressions, social-conventional transgressions, and personal choices. This study also questions whether children are more likely to cite biocentric or homocentric reasons when justifying their judgments of environmentally harmful behaviors. To answer these questions, sixty-one 6–10 year olds were asked to judge the severity of various actions that impact the environment. For comparison, participants also judged moral transgressions, social-conventional transgressions, and personal choices. Children judged actions that harm the environment more severely than social-conventional transgressions but not as severely as moral transgressions. When justifying their judgments of these environmentally harmful behaviors, participants were more likely to reference biocentric reasons as compared to homocentric reasons. The findings suggest that children perceive harm to the environment as bad, but harm to humans as worse.     

Comparison of life-cycle energy and emissions footprints of passenger transportation in metropolitan regions

A comparative life-cycle energy and emissions (greenhouse gas, CO, NO_X, SO₂, PM₁₀, and VOCs) inventory is created for three U.S. metropolitan regions (San Francisco, Chicago, and New York City). The inventory captures both vehicle operation (direct fuel or electricity consumption) and non-operation components (e.g., vehicle manufacturing, roadway maintenance, infrastructure operation, and material production among others). While urban transportation inventories have been continually improved, little information exists identifying the particular characteristics of metropolitan passenger transportation and why one region may differ from the next. Using travel surveys and recently developed transportation life-cycle inventories, metropolitan inventories are constructed and compared. Automobiles dominate total regional performance accounting for 86–96% of energy consumption and emissions. Comparing system-wide averages, New York City shows the lowest end-use energy and greenhouse gas footprint compared to San Francisco and Chicago and is influenced by the larger share of transit ridership. While automobile fuel combustion is a large component of emissions, diesel rail, electric rail, and ferry service can also have strong contributions. Additionally, the inclusion of life-cycle processes necessary for any transportation mode results in significant increases (as large as 20 times that of vehicle operation) for the region. In particular, emissions of CO₂ from cement production used in concrete throughout infrastructure, SO₂ from electricity generation in non-operational components (vehicle manufacturing, electricity for infrastructure materials, and fuel refining), PM₁₀ in fugitive dust releases in roadway construction, and VOCs from asphalt result in significant additional inventory. Private and public transportation are disaggregated as well as off-peak and peak travel times. Furthermore, emissions are joined with healthcare and greenhouse gas monetized externalities to evaluate the societal costs of passenger transportation in each region. Results are validated against existing studies. The dominating contribution of automobile end-use energy consumption and emissions is discussed and strategies for improving regional performance given private travel's disproportionate share are identified.