Transport impacts on atmosphere and climate: Shipping

Emissions of exhaust gases and particles from oceangoing ships are a significant and growing contributor to the total emissions from the transportation sector. We present an assessment of the contribution of gaseous and particulate emissions from oceangoing shipping to anthropogenic emissions and air quality. We also assess the degradation in human health and climate change created by these emissions. Regulating ship emissions requires comprehensive knowledge of current fuel consumption and emissions, understanding of their impact on atmospheric composition and climate, and projections of potential future evolutions and mitigation options. Nearly 70% of ship emissions occur within 400 km of coastlines, causing air quality problems through the formation of ground-level ozone, sulphur emissions and particulate matter in coastal areas and harbours with heavy traffic. Furthermore, ozone and aerosol precursor emissions as well as their derivative species from ships may be transported in the atmosphere over several hundreds of kilometres, and thus contribute to air quality problems further inland, even though they are emitted at sea. In addition, ship emissions impact climate. Recent studies indicate that the cooling due to altered clouds far outweighs the warming effects from greenhouse gases such as carbon dioxide (CO₂) or ozone from shipping, overall causing a negative present-day radiative forcing (RF). Current efforts to reduce sulphur and other pollutants from shipping may modify this. However, given the short residence time of sulphate compared to CO₂, the climate response from sulphate is of the order decades while that of CO₂ is centuries. The climatic trade-off between positive and negative radiative forcing is still a topic of scientific research, but from what is currently known, a simple cancellation of global mean forcing components is potentially inappropriate and a more comprehensive assessment metric is required. The CO₂ equivalent emissions using the global temperature change potential (GTP) metric indicate that after 50 years the net global mean effect of current emissions is close to zero through cancellation of warming by CO₂ and cooling by sulphate and nitrogen oxides.     

Optimal Loading Rates and Economic Analyses for Anaerobic Digestion of Poultry Waste

ABSTRACT

Four combinations of litter and carcasses from broiler chickens were examined utilizing a thermophilic, stirred-tank digester of demonstration size of approximately 10,000 gal. Under computed optimal loading rates, litter with paper bedding had the highest daily production of methane over an 8-day retention period. The greatest methane production per lb of volatile solids was achieved over 10 days with litter and paper bedding combined with carcasses. This research found that sufficient poultry litter is generated within 20 mi (32 km) of Moorefield, WV, to support a commercial-sized digester operation. However, anaerobic digestion of poultry waste cannot be financially supported by methane production alone. To be financially viable, anaerobic digestion requires a disposal fee for poultry waste and/or the sale of the digested solid effluent as an organic fertilizer to retail markets.     

Determinants of coverage in Community‐based Therapeutic Care programmes: towards a joint quantitative and qualitative analysis

One of the most important elements behind the success of Community‐based Therapeutic Care (CTC) programmes for the treatment of severe acute malnutrition has been their ability to achieve high levels of coverage. In CTC, coverage is measured using the Centric System Area Sampling (CSAS) method, which provides accurate and reliable estimates of programme coverage as well as information on the primary reasons for non‐attendance. Another important feature of CTC programmes is their use of socio‐cultural assessments to determine potential barriers to access and to develop context‐specific responses. By analysing data on non‐attendance provided by CSAS surveys, in conjunction with data from socio‐cultural assessments, it is possible to identify common factors responsible for failures in programme coverage. This paper focuses on an analysis of data from 12 CTC programmes across five African countries. It pinpoints three common factors (distance to sites, community awareness of the programme, and the way in which rejections are handled at the sites) that, together, account for approximately 75 per cent of non‐attendance.     

A study of emissions from a Euro 4 light duty diesel vehicle with the European particulate measurement programme

The California Air Resources Board, CARB, has participated in a program to quantify particulate matter (PM) emissions with a European methodology, which is known as the Particulate Measurement Programme (PMP). The essence of the PMP methodology is that the diesel PM from a Euro 4 vehicle equipped with a Diesel Particulate Filter (DPF) consists primarily of solid particles with a size range greater than 23 nm. The PMP testing and the enhanced testing performed by CARB have enabled an increased understanding of both the progress that has been made in PM reduction, and the future remaining challenges for new and improved DPF-equipped diesel vehicles. A comparison of measured regulated emissions and solid particle number emissions with the results obtained by the PMP participating international laboratories was a success, and CARB’s measurements and standard deviations compared well with the other laboratories. Enhanced measurements of the influence of vehicle conditioning prior to testing on PM mass and solid particle number results were performed, and some significant influences were discovered. For example, the influence of vehicle preconditioning on particle number results was significant for both the European and USA test driving cycles. However, the trends for the cycles were opposite with one cycle showing an increase and the other cycle showing a decrease in particle number emissions. If solid particle size distribution and total particle numbers are to be used as proposed in PMP, then a greater understanding of the quality and errors associated with measurement technologies is advisable.In general, particle counting instruments gave results with similar trends, but cycle-to-cycle testing variation was observed. Continuous measurements of particle number concentrations during test cycles have given detailed insight into PM generation. At the present time there is significant variation in the capabilities of the particle counting instruments in terms of particle size and concentration.Current measurements show the existence of a large number of volatile and semi-volatile particles of yet-to-be-resolved chemical composition in diesel exhaust, especially during DPF regeneration, and these particles are not included in the PMP methodology because they are smaller than 20 nm. It will be very challenging to improve our understanding of this class of diesel particulate matter.     

Ecotechnological methods as strategies to reduce eutrophication and acidification in lakes

Ecotechnological methods have been employed by developed countries like the United States of America, Europe, Australia and Japan in the restoration of their degraded freshwater ecosystems. These methods according to literature sources, in many cases have produced the desired results in these countries where they have been implemented. This article is aimed at providing an overview on aspects of available ecotechnological methods employed in the reduction of eutrophication and acidification and in Lake Ecosystem restoration in general. Ecotechnological methods offer great opportunities for developing countries with tropical or subtropical climates due to their cost-effectiveness. The efficacy and potential limitations of the various methods in their respective restorative approach is also reported in this article.     

A rapid evidence assessment of the potential risk to the environment presented by active ingredients in the UK’s most commonly sold companion animal parasiticides

A number of parasiticides are commercially available as companion animal treatments to protect against parasite infestation and are sold in large volumes. These treatments are not intended to enter the wider environment but may be washed off or excreted by treated animals and have ecotoxic impacts. A systematic literature review was conducted to identify the existing evidence for the toxicity of the six most used parasiticides in the UK: imidacloprid, fipronil, fluralaner, afoxolaner, selamectin, and flumethrin. A total of 17,207 published articles were screened, with 690 included in the final evidence synthesis. All parasiticides displayed higher toxicity towards invertebrates than vertebrates, enabling their use as companion animal treatments. Extensive evidence exists of ecotoxicity for imidacloprid and fipronil, but this focuses on exposure via agricultural use and is not representative of environmental exposure that results from use in companion animal treatments, especially in urban greenspace. Little to no evidence exists for the ecotoxicity of the remaining parasiticides. Despite heavy usage, there is currently insufficient evidence to understand the environmental risk posed by these veterinary treatments and further studies are urgently needed to quantify the levels and characterise the routes of environmental exposure, as well as identifying any resulting environmental harm.

     

Engaging with the Ecological Footprint as a Decision-Making Tool: Process and Responses

Since the initial development of the Ecological Footprint in the early 1990s, the concept has gained increased interest amongst academics and practitioners internationally. In the UK, it is estimated that some 60 to 70 Ecological Footprint studies were undertaken between 1999 and 2004. Although the majority of interest in Ecological Footprinting has come from local government, a recent study has found that government officers involved in the formulation of council policy have not been able to engage with the Ecological Footprint as a process or use the results to inform policy decisions. This paper analyses how an Ecological Footprint has been developed for Cardiff, the capital city of Wales. The approach used to construct an Ecological Footprint for Cardiff has been significantly different to that which had been used previously in the UK, as it has involved a unique consortium of researchers at Cardiff University and policy development officers at Cardiff Council checking the quality of data used in the Footprint calculation, and developing a range of policy scenarios.     

Escape from competition: neighbors reduce Centaurea stoebe performance at home but not away

The greater abundance of some exotic plants in their nonnative ranges might be explained in part by biogeographic differences in the strength of competition, but these competitive effects have not been experimentally examined in the field. We compared the effects of neighbors on the growth and reproduction of spotted knapweed (Centaurea stoebe) in Europe, where it is native, and in Montana, where it is invasive. There were strong negative competitive effects of neighboring vegetation on C. stoebe growth and reproduction in Europe. In contrast, identical experiments in Montana resulted in insignificant impacts on C. stoebe. Although the mechanisms that produce this dramatic biogeographic difference in competitive outcome remain unknown, our results indicate that differences in net competitive interactions between ranges may contribute to the striking dominance of C. stoebe in parts of North America.     

Applications of time-resolved laser fluorescence spectroscopy to the environmental biogeochemistry of actinides

Time-resolved laser fluorescence spectroscopy (TRLFS) is a useful means of identifying certain actinide species resulting from various biogeochemical processes. In general, TRLFS differentiates chemical species of a fluorescent metal ion through analysis of different excitation and emission spectra and decay lifetimes. Although this spectroscopic technique has largely been applied to the analysis of actinide and lanthanide ions having fluorescence decay lifetimes on the order of microseconds, such as UO , Cm, and Eu, continuing development of ultra-fast and cryogenic TRLFS systems offers the possibility to obtain speciation information on metal ions having room-temperature fluorescence decay lifetimes on the order of nanoseconds to picoseconds. The main advantage of TRLFS over other advanced spectroscopic techniques is the ability to determine in situ metal speciation at environmentally relevant micromolar to picomolar concentrations. In the context of environmental biogeochemistry, TRLFS has principally been applied to studies of (i) metal speciation in aqueous and solid phases and (ii) the coordination environment of metal ions sorbed to mineral and bacterial surfaces. In this review, the principles of TRLFS are described, and the literature reporting the application of this methodology to the speciation of actinides in systems of biogeochemical interest is assessed. Significant developments in TRLFS methodology and advanced data analysis are highlighted, and we outline how these developments have the potential to further our mechanistic understanding of actinide biogeochemistry.     

Deep sea benthic bioluminescence at artificial food falls, 1,000–4,800 m depth,in the Porcupine Seabight and Abyssal Plain,North East Atlantic Ocean

Natural bioluminescence (that not mechanically stimulated by human intervention) produced by organisms on the seafloor of the northeast Atlantic ocean between 970 and 4,800 m depth was examined using an image intensifying (ISIT) camera mounted on an autonomous lander system. In the absence of bait little or no luminescence was observed but with bait present there was a significant inverse relationship with depth, Log₁₀ (1 + number of events h⁻¹) = 1.7627–0.3235 depth (km) (r ² = 0.8158, P < 0.001) indicating an average of 2.6 events h⁻¹ at 4 km and 28 h⁻¹ at 1 km. But in an area at ca. 1 km depth near carbonate and coral mounds the mean was 133 events h⁻¹, much higher than predicted. In this bioluminescent hot spot 52–483 events h⁻¹ were observed including moving luminescent targets and release of patches of luminescent material into the water around the bait so that on occasions the whole area around the bait was illuminated persisting on a time scale of minutes. At abyssal depths, luminescence was much less than reported at similar depths in the tropical NE Atlantic off Cape Verde. The sources of luminescence could not be determined but in the most active areas were associated with presence of eels Synaphobranchus kaupii which although themselves not luminescent may have stimulated luminescence from prey organisms such as ostracods (Vargula norvegica).