The goal of quantifying the woody cover and biomass of tropical savannas, woodlands and forests using satellite data is becoming increasingly important, but limitations in current scientific understanding reduce the utility of the considerable quantity of satellite data currently being collected. The work contained in this thesis reduces this knowledgegap, using new field data and analysis methods to quantify changes using optical, radar and LiDAR data. The first paper shows that high-resolution optical data (Landsat & ASTER) can be used to track changes in woody vegetation in the Mbam Djerem National Park in Cameroon. The method correlates a satellite-derived vegetation index with field-measured canopy cover, and the paper concludes that forest encroached rapidly into savanna in the region from 1986-2006. Using the same study area, but with radar remote sensing data from 1996 and 2007 (ALOS PALSAR & JERS-1), the second paper shows that radar backscatter correlates well with field-measured aboveground biomass (AGB). This dataset confirms the woody encroachment within the park; however, in a larger area around the park, deforestation dominates. The AGB-radar relationships described above are expanded in the next paper to include field plots from Budongo Forest (Uganda), the Niassa Reserve (north Mozambique), and the Nhambita Community Project (central Mozambique). A consistent AGB-radar relationship is found in the combined dataset, with the RMSE for predicted AGB values for a site increasing by <30 %, compared with a site-specific equation, when using an AGB-radar equation derived from the three other sites. The study of the Nhambita site is extended in the following paper to assess the ability of radar to detect change over short time periods in this environment, as will be needed for REDD (Reducing Emissions from Deforestation and Degradation). Using radar mosaics from 2007 and 2009, areas known (from detailed ground data) to have been degraded decreased in AGB in the radar change detection, whereas areas of agroforestry and forest protection showed small increases.

Biogenic volatile organic compounds (BVOC) are a wide-ranging group of trace gas components in the atmosphere which are emitted naturally from Earth’s surface. It is now recognised that biogenically sourced VOCs are far more significant on a global scale than those from anthropogenic sources, with up to 10 times greater emissions. Very few field-based studies of fluxes from plant canopies have been undertaken, particularly for non-terpenoid compounds. This thesis presents mixing ratio and flux measurements of BVOC from a range of temperate plant canopies: Douglas fir, short-rotation coppice willow, Miscanthus and mixed peatland vegetation. The virtual disjunct eddy covariance technique (vDEC) using a proton transfer reaction mass spectrometer (PTR-MS) as a fast VOC sensor was used for all measurements except for peatlands, where grab samples were collected on adsorbent sampling tubes for later chromatographic analysis. The PTR-MS was also utilised for measuring the rate of degradation of VOCs during laboratory chamber experiments. Mixing ratios and fluxes of VOCs measured within and above a Douglas fir forest were the first canopy-scale measurements for this species. Fluxes of monoterpenes were comparable to previous studies while isoprene was also detected (standard emissions factors up to 1.15 μg gdw -1 h-1 and 0.18 μg gdw -1 h-1, respectively). Emissions of oxygenated VOCs were also found to be significant, highlighting the importance of quantifying a wider variety of VOCs from biogenic sources, other than isoprene and monoterpenes. Results for bioenergy crops Miscanthus and willow showed that willow was a high isoprene emitter (20 μg gdw -1 h-1), but no measureable VOCs were detected from Miscanthus. This indicates that future expansion of bioenergy crops, and hence species selection, should take resultant air quality and human health impacts – due to changing VOC emissions – into account. Fluxes of BVOC from a Scottish peatland are the first reported measurements for this ecosystem in a temperate climate. Additionally, to assess the impact of nitrogen deposition on VOC fluxes, BVOC measurements were taken from sample plots in a pre-existing, long-term field manipulation study to assess impacts of wet nitrate or ammonium deposition on peatland. The peatland was found to be a significant source of isoprene and monoterpenes (590 and 1.5 μg m-2 h-1 respectively) and there was evidence that emissions were affected by wet nitrogen treatment. Isoprene emissions were reduced by both nitrate and ammonium treatment, while nitrate increased β- pinene fluxes. Increasing atmospheric nitrogen concentrations are therefore predicted to have an impact on VOC emission. Chamber studies showed that the rate of loss of α-pinene from the gas-phase during oxidation – and hence potential formation of secondary organic aerosol (SOA) – decreased with increasing isoprene mixing ratio. This was not observed for limonene. These results show that as isoprene mixing ratios increase with increasing global temperatures, negative feedback on radiative forcing from SOA particles may be suppressed. Results from this thesis provide valuable experimental data for a range of temperate plant canopies, which will help constrain modelled predictions of future VOC emissions. Additionally, the importance of understanding the effects of land use and environmental change on VOC emissions was demonstrated.

Soil CO2 efflux (F-soil) represents a significant source of ecosystem CO2 emissions that is rarely quantified with high-temporal-resolution data in carbon flux studies. F-soil estimates can be obtained by the low-cost gradient method (GM), but the utility of the method is hindered by uncertainties in the application of published models for the diffusion coefficient. Therefore, to address and resolve these uncertainties, we compared F-soil measured by 2 soil CO2 efflux chambers and F-soil estimated by 16 gas transport models using the GM across 1year. We used 14 published empirical gas diffusion models and 2 in situ models: (1) a gas transfer model called Chamber model obtained using a calibration between the chamber and the gradient method and (2) a diffusion model called SF6 model obtained through an interwell conservative tracer experiment. Most of the published models using the GM underestimated cumulative annual F-soil by 55% to 361%, while the Chamber model closely approximated cumulative F-soil (0.6% error). Surprisingly, the SF6 model combined with the GM underestimated F-soil by 32%. Differences between in situ models could stem from the Chamber model implicitly accounting for production of soil CO2, while the conservative tracer model does not. Therefore, we recommend using the GM only after calibration with chamber measurements to generate reliable long-term ecosystem F-soil measurements. Accurate estimates of F-soil will improve our understanding of soil respiration's contribution to ecosystem fluxes.

The presence of competitors and predators as well as plant quality affect which plants an insect feed from. These factors affect food choice through the entire insect life cycle, and is especially important when it comes to nurturing larvae. Females oviposition choice sets the initial stage for larval growth and survival, and it is therefore predicted that there is a strong selection pressure to make them oviposit on the best plants possible. This study looks into the behavior of nutrient driven ovipositing and food choice in the beetles Phratora vitellinae and Lochmaea caprea by offering individuals ten leaves of Salix viminalis, one treated with extra nitrogen in order to increase the nutritional value, and four treated with extra carbon, which should lower the nutritional value. During the choice experiment, only two females of Phratora vitellinae oviposited, making it impossible to draw any conclusion regarding nutrient driven oviposition choice. However, data showed a preference for nitrogen treated leaves and an avoidance of untreated control leaves in almost every case when looking into the largest loss of area for leaves of each treatment. When analyzing the number of leaves of each treatment that is eaten per individual there was a slight preference for nitrogen treated leaves, even though the probability of nitrogen being ranked as most preferred in this case was almost zero. Carbon treated leaves and acetone treated control leaves were equally avoided. For Lochmaea caprea, females fed from a significantly larger numer of leaves than males did (t-test, t=1.86, p=0.0003). An ANOVA showed no significant difference in C:N ratio among leaf treatments (ANOVA, F=9.28E-07, p=0.99). Since plant C:N ratio most likely will increase continuously due to CO2 emissions, the effects an increased carbon concentration in plant tissues has on oviposition and food choice in herbivorous insects is something to look further into. More studies on this subject are therefore needed.

This paper examines the Environmental Kuznets Curve (EKC) hypothesis and tests for causality using Dynamic Ordinary Least Squares (DOLS) and the Vector Error Correction Model (VECM). There is evidence of long-run relationships in the three models under consideration. The Dynamic Ordinary Least Squares (DOLS) finds no evidence to support the existence of an environmental Kuznets curve (EKC) hypothesis for Zambia in the long-run. The evidence from the long-run suggests an opposite of the Environmental Kuznets Curve (EKC), in that the results indicate a U-shaped curve relationship between income and carbon emission. The conclusion on causality based on the VECM is that there is evidence of neutrality hypothesis between either total electricity and income or between industrial electricity and income in the short-run Additionally, there is evidence of conservation hypothesis in the context of residential and agricultural electricity consumption.

Research using microalgae Chlorella vulgaris was conducted in order to determine the maximum CO2 concentration under which algae can grow, within the emission range from oil and natural gas burning plants (0-20%). After choosing the optimal CO2 percentage, pH and alkalinity were determined; and finally, an electrochemical (EC) batch reactor connected to DC current was applied to achieve algae cell annihilation, and therefore, facilitate anaerobic digestion, methane production and energy recovery. It was determined that algae can grow under 20% CO2, being 15% CO2 the most effective (pH of 6.64 and alkalinity of 617.5 mg/L CaCO3). Electroporation using an electrochemical batch reactor is effective in breaking cells membranes, which simplifies anaerobic digestion process and methane production. The parameters found effective for completely breaking the algae cell are: detention time of 1 more or less 0.5 minutes, and minimum voltage and current of 65 Volts/285 ml and 3.9 Amps/285 ml, respectively

Die anspruchsvollen Zielsetzungen zum CO2-Ausstoß von Kraftfahrzeugen verlangen immer stärker nach hocheffizienten Fahrzeugkonzepten und werden zukünftig zu deutlich höheren Elektrifizierungsanteilen der Antriebe führen. Die große Herausforderung liegt dabei in der Lösung des Zielkonfliktes zwischen voll elektrischem Fahren und erstfahrzeugtauglicher Reichweite. Im Rahmen eines Forschungsprojektes zur Konzeption von Hybridfahrzeugen hat die BMW Forschung ein Konzeptfahrzeug entwickelt, das im urbanen Bereich emissionsfrei betrieben werden kann und dennoch alltagstauglich für spontane längere Fahrten nutzbar ist (Abbildung 1). Die für dieses Projekt abgeleiteten Ziele waren ein Verbrauch von < 2,5 l im Ladungserhaltungsbetrieb, eine E-Reichweite von 100 km, eine BMW-adäquate Beschleunigung von < 8 sec von 0 auf 100 km/h, eine erstfahrzeugtaugliche Höchstgeschwindigkeit von 180 km/h, ein Raumangebot auf Niveau heutiger viersitziger Coupés im Kompaktsegment und eine Gesamtreichweite von 1.000 km (Eiletz 2015a). Im Rahmen des Beitrags werden sowohl Prozess und Vorgehensweise bei der Gestaltung des Hocheffizienz-Konzeptfahrzeugs als auch die Ergebnisse des Forschungsprojektes dargelegt.

Aus der Einleitung: "Xenobiotika werden durch den Menschen in die Stoffkreisläufe der Natur eingebracht, sie sind dort ursprünglich nicht anzutreffen. Dazu zählen auch Medikamente, die der menschliche Körper in kurzer Zeit wieder ausscheidet ohne diese abzubauen. Die bestehenden Abwasserreinigungsanlagen sind derzeit nicht in der Lage diese Frachten vollständig zu eliminieren, sodass sie unweigerlich in die Umwelt gelangen und dort undefiniert Einfluss nehmen. Xenobiotika können bereits in den großen Wasserreservoirs der Erde detektiert werden, die Prognose für die nächsten Jahre zeigt eine 30% Steigerung der Emissionen auf. In Deutschland gelangen z.B. jährlich 63 Tonnen des Schmerzmittels Diclofenac in die Flüsse (Bundesumweltamt 2014). Der Mensch hinterlässt regelrechte anthropogene Fußabdrücke, bestehend aus Schmerzmitteln, Antibiotika und Hormonen. Die problematischen Emissionen einiger Xenobiotika treten anhand von Folgeerscheinungen weltweit immer gravierender zutage (Bundesumweltamt 2014). So müssen das globale Artensterben (Geier in Indien), die Verweiblichung von Tierpopulationen in aquatischen Systemen und Krebserkrankungen mit partiell hohen Xenobiotika-Belastungen in der Umwelt in Zusammenhang gebracht werden. Die Entfernung von Xenobiotika insbesondere aus den Wasserkreisläufen stellt eine große ökonomische als auch ökologische Herausforderung zum Schutz der Lebensräume dar. ..."

Over the last four decades emissions trading has enjoyed a high profile in environmental law scholarship and in environmental law and policy. Much of this regulatory discussion is promotional, preferring emissions trading above other regulatory strategies without, however, engaging with legal complexities embedded in conceptualising, scrutinising and managing emissions trading schemes. The combined effect of these debates is to create a perception that emissions trading is a straightforward regulatory strategy, imposable across various jurisdictions and environmental settings. This thesis shows that this view of emissions trading is problematic for at least two reasons. First, emissions trading responds to distinct environmental and non-environmental goals, including creating profit-centres, establishing a governance regime aimed at substituting state control of common resources, and ensuring regulatory compliance. This is important, as the particular purpose entrusted to a given emissions trading regime has, as its corollary, a particular governance structure, according to which the regime may be constructed and managed. Second, the governance structures of emissions trading regimes are culture- specific, which is a significant reminder of the importance of law in understanding not only how emissions trading schemes function but also what meaning is given to them as regulatory strategies. This is shown by deconstructing emissions trading discourses: that is, by inquiring into the assumptions about emissions trading that feature in the literature and in debates involving law- and policymakers and the judiciary at the EU level. Ultimately, this thesis makes a strong argument for reconfiguring the common understanding of emissions trading schemes as regulatory strategies, and sets out a framework for analysis to sustain that reconfiguration.

Direct fuel injection technology is increasingly being applied to the spark ignition internal combustion engine as one of the many actions required to reduce the CO2 emissions from road transport. Whilst the potential for CO2 reductions is compelling, the technology is not without disadvantages. Early examples typically emitted over an order of magnitude more Particulate Matter (PM) than vehicles with conventional spark ignition engines. Consequently, future revisions to European and North American exhaust emissions legislation are likely to regulate the particulate emissions from vehicles with direct injection gasoline engines. This thesis undertakes to investigate a) instrumentation capable of simultaneously resolving the number concentration and size distribution of particles in the 5-1000 nm size range and b) the factors affecting the PM emissions from spark ignition engines with direct fuel injection. The first objective is achieved by evaluation and comparison of a differential mobility spectrometer; photo-acoustic soot sensor; condensation particle counter and electrical low pressure impactor. To address the second question, a differential mobility spectrometer is applied to quantify the PM emissions from a number of direct injection gasoline engines, together with investigation of their dependence on various calibratable parameters, operating temperature and fuel composition. The differential mobility spectrometer showed good agreement with the other more established instruments tested. Moreover, it exhibited a faster time response and finer resolution in particle size. The number weighted size distribution of the PM emitted was typically lognormal with either one or two modes located between 20 and 100 nm. Chemical analysis of PM samples showed the presence of elemental carbon, volatile organic material and sulphates. Transient PM measurements enabled short time-scale events such as mode switching between homogeneous and stratified mixture preparation to be identified. PM number concentrations in stratified mode exceeded those in homogeneous mode by a factor of 10-100. Dynamometer based experiments showed that PM emissions increase for rich air fuel ratios, retarded fuel injection and advanced ignition events. They also demonstrated a strong dependence on fuel composition: the highest PM emissions were measured with an aromatic fuel, whereas blending alcohols such as methanol or ethanol tended to suppress PM emissions, particularly in the accumulation mode size range. These measurements are amongst the first of their kind and demonstrate the applicability of the differential mobility spectrometer to the measurement of ultra-fine particulate emissions from engines with direct fuel injection systems. Numerous explanations are put forward to describe the data obtained, together with suggestions for future work on PM control and abatement.