Our understanding of phosphorus (P) transfer is limited by a lack of available data with which to investigate the effects of scale. To rectify this, an extensive programme of field monitoring was undertaken at ADAS Rosemaund, Herefordshire. Monitoring was carried out at the hillslope patch (37 m to 111 m), the hillslope/field (1.9 to 3.7 ha) and the catchment (30.6 ha) scales, which were nested where possible and designed to ensure connectivity between scales. Twenty-eight hydrological events were monitored within the 2004-2005 and 2005-2006 hydrological years for discharge and suspended sediment, of which six events were monitored for P. The results showed that surface runoff was relatively unimportant in P transfer within the catchment, accounting for 1% of the catchment P loads from 6% of the area, as surface runoff generation and stream connectivity were spatially limited. Drainflow was the main process of P transfer from the hillslopes, which is likely to relate to the linkage of macropores to the field drains. The influence of land management practices, particularly artificial drainage and tractor wheelings, on P transfer processes and connectivity was evident throughout the analysis. The dominant P transfer processes varied between scales; P transfer was dominated by rainfall intensity and surface runoff at the hillslope patch scale, by rainfall volume and drainflow at the hillslope/field scale, and by rainfall volume, drainflow and instream processes at the catchment scale. Despite the differences in process operation observed, the data showed strong linkages between scales, allowing empirical relationships to be developed between concentration data for the hillslope patch and hillslope/field scales, and between event characteristics for the hillslope/field and catchment scales. A conceptual model of P transfer was revised to include modifications to the processes and to show the effects of scale on P transfer in small agricultural catchments.

This thesis looks at the role that technical knowledge plays in the transition in industry away from pollution-intensive production methods. It uses econometric techniques and qualitative analysis to test three aspects of the relationship between knowledge and pollution-saving technological change-related outcomes, all in the context of US industry, and all with respect to conventional pollutants. The first paper observes that the level of industrial environmental R&D spending steadily declined from the late 1970s onward. Employing an estimation model with industry fixed effects, the hypothesis is tested that this decline was the result of the conditioning effect of greater flexibility in the design of the environmental policy on the environmental regulatory burden born by industry. The second paper investigates the sources of the change in SO2 intensity of electricity production undergone by electric power plants under the SO2 cap and trade program. Mixed methods including quantile regression are used to compare the effect of frontier technical knowledge on the extent of change undergone, relative to the effect of knowledge un-intensive techniques. The third paper investigates why a small number of inventions aimed at controlling pollution from automobiles turned out to be so much more technologically influential than the great majority of comparable inventions, which exerted very little technological influence at all. Negative binomial regression is used to test the effect of the composition of the stock of knowledge that the automobile companies brought to bear on the inventive process. These studies find that pollution-saving technological change is characterised more by the repurposing and adaptation of existing knowledge and by the churn among existing technologies, than by universal technological advance in dedicated environmental technologies. The implications for climate mitigation policy are discussed in the conclusions.

Helm (2008) asked: 'Climate change policy: why has so little been achieved?' Cultural Theory (CT) has been used to analyse the debate over climate change, arguing that competing worldviews mandate divergent policy responses (Rayner & Malone 1998). CT's framework suggests the monolithic structure of the UNFCCC process fails to integrate these multiple worldviews, hindering effective action. This thesis uses a complementary framework, Fiske's (1992) Relational Model's Theory (RMT). Whereas CT analyses the debate at the societal level, RMT proposes a framework of individual social cognition comprising four models of social exchange: 'Equality Matching', based upon reciprocity; 'Communal Sharing', based on equal entitlement within a community; 'Authority Ranking', based upon established status; and 'Market Pricing', based on an external currency of merit. RMT implies that the relational models found in individual cognition should be mirrored in any debate at the societal and inter-personal levels. Content analyses of media articles and focus group interviews support the view that there are four coherent Standpoints matching these relational models in the debate. Survey respondents who believe in climate change used different models from those who did not, but survey evidence also gave support to the view that individuals use multiple models to reason over novel or contested issues such as climate change. CT explicitly argues that one of the four hypothesised worldviews, the 'fatalist', is not active in shaping policy. In contrast, these empirical studies suggest that the closest equivalent relational model, Equality Matching, generates the Commons Dilemma (Hardin, 1968) that actually drives much of the debate. The studies also raised new questions about the structure connecting the four relational models, or the worldviews. Lastly, the framework confirms it will be difficult to get concerted action before climate change impacts intensify, at which point social as well as climate thresholds will have been crossed.

The tropospheric composition of organohalogens and alkyl nitrates have been investigated from tropical and temperate environments. Ground based measurements and aircraft data are presented from the Oxidant and Particle Photochemical Processes (OP3) project, conducted in Borneo, 2008. Controlled experiments of temperate vegetation were also conducted to assess the emission of methyl halides from crop plants. Methyl halide results from OP3 contradict current assumptions of a strong source from tropical vegetation. High mixing ratios of methyl chloride and chloroform were observed in the boundary layer over oil palm plantations. OP3 aircraft data suggests that the oil palm plantations facilitate the formation of C2 to C4 alkyl nitrates. There was evidence that the southeast coast of Sabah is a source region for the bromocarbons measured. The short lived bromocarbons contribute to a bromine budget of 4- 6 ppt; this corroborates recent modelling estimates of their contribution to the stratospheric burden. In controlled experiments it was confirmed that the gene responsible for the emission of methyl halides is the HOL (HARMLESS TO THE OZONE LAYER) gene. The current WMO estimate for rapeseed contribution to the natural methyl bromide budget was shown to be an overestimate, based on the varieties studied in this thesis. Methyl iodide emissions from rice plants grown in soils were observed to be significantly lower than reported from rice paddies in the literature, suggesting that the growth conditions contribute to the production of methyl iodide.

International trade adds a thick layer of complexity to climate change mitigation efforts. Questions such as “Who is responsible for the emissions from China’s export sectors?” and “Will strengthening domestic climate policy measures lead to relocation of industry and emissions to countries with lax regulation?” are intensely discussed, both in policy and academic circles. Robust evidence on these issues remains limited, however. Many studies have quantified the volumes of embodied carbon in international trade using complex models, but the results appear very sensitive to the model specification, and conflicting results are reported across different studies. Similarly, the evidence on trade impacts from emissions reduction policies has so far relied largely on model simulations. This thesis combines two strands of work. The first part focuses on embodied carbon quantification. It critically reviews and compares the results and methods of existing work then goes on to conduct a first quantification exercise of global embodied carbon in bilateral trade at the product level. The second part measures the response of bilateral trade to industrial energy prices. It estimates the effect of energy price differences on bilateral trade flows, using a panel dataset covering over 80% of global merchandise trade over 16 years. These estimations are used to infer the effect of carbon price differences on trade. The first part reveals a complex mapping of global embodied carbon flows, contrary to the simplified picture portrayed by previous studies using aggregated models. Embodied carbon is found to be particularly concentrated in certain products and in regional trade. It suggests that rather viewing it as an Annex I vs non Annex I issue, grouping countries according to patterns of production and consumption may be more relevant in discussions surrounding climate policy and trade. The second part of the thesis finds evidence that trade tends to develop more between countries with different energy prices. However, this effect is small in magnitude and focused on a few sectors. The findings suggest that measures to ’prevent’ carbon leakage may have limited impact on most sectors, and should be targeted to those most likely to face adverse trade impacts.

Field, experimental and theoretical investigations have been carried out into the electrification of volcanic plumes. At Sakurajima volcano, Japan, ground-level perturbations of the atmospheric electric potential gradient generated by particulate plumes were recorded. Simultaneous measurements, made at up to five sites around the volcano, are shown to be capable of detecting even very small quantities of volcanic particles, and tracking a continuously produced (over a period of several hours), dilute plume as it was dispersed by the wind. Data collected during one small Vulcanian eruption suggest that charges, about 1 C in magnitude, were generated and then separated, with the positive charge centre residing above the negative charge centre. Experiments have been carried out in order to assess fracto-emission (the release of ions, neutral atoms and various frequencies of electromagnetic radiation from fracture surfaces) as a charging mechanism for the electrification of silicate particles in plumes. Silicate particles, generally less than 100 µm in diameter, were produced by colliding pumice samples together and were shown to have net specific charges of approximately 10-5 to 10-6 C kg-1 (similar to previous field measurements on ashfall). Most (but not all) of the experimental samples produced net negatively charged ash, and demonstrated a positive-above-negative charge separation. Additional charge thought to have been released in the form of ions was also detected, supporting fracto-emission as the charging mechanism for volcanic plumes. The magnitude of the net ash charge is shown to be a function of the particle size, with relative humidity having only a small effect. The polarity of the net charge appears to be a function of a property of individual pumice types, possibly their geochemistry. Experiments during which the particles were separated by their polarity indicate that the net charges reflect only a small imbalance in much larger, individual particle charges (10-3 C kg-1) of both polarities. The particle charges are shown to vary with the sample impact velocity, the number of impacts carried out within an experiment and, to a lesser degree, relative humidity. Variation within the results appears to be partly an effect of particle aggregation within the experiment. Investigation of any effects that this particle charging may have on the plumes observed on Io (one of Jupiter’s moons) suggests that luminous discharges and particle aggregation are both probable in this environment. It is shown that the distinct asymmetries observed in plumes are unlikely to be a result of electromagnetic interactions, but probably represent decompression features and asymmetric vent or crater morphologies.

This study identifies power relationships within forest conservation decision-making in Nova Scotia, Canada. Rather than rely on the ‘customary science’ of resource conservation largely based on biological and physical parameters, this analysis is steeped in the traditions of social science and policy analysis. This study’s central focus is the Forest Improvement Act (FIA): 1962-1986. Forest conservation policies and legislative initiatives developed prior to FIA enactment such as the Small Tree Act (STA): 1942 - 1965 are treated in this study as the FIA’s policy gestation period. Theoretical and practical insights derived from this pre-FIA period are used in the assessment of the FIA and these combined understandings are subsequently applied to the analysis of contemporary forest conservation policy. For contemporary analysis, six case studies including the Nova Scotia Envirofor process and the St. Mary’s River Landscape and Ecology Management proposal, as well as a recent provincial government initiative are examined. This study utilises a broad range of decision-making and resource management theory to tease out understandings of the particular character of the policy process. The analysis utilises various decision-making models, theories of power, and multi-agency decision making models as well as the Environmental Modernisation literature developed by Turner, O’Riordan and Weale and others. In addition to the investigative methodologies used generally throughout this study, the Envirofor and the St. Mary’s case studies employed a ‘participant observer’ approach that provided otherwise unavailable insights into these conservation initiatives. Regardless of policy content, this study shows that external forces such as woodfibre markets were key to the implementation of ground level forest conservation. Ironically, this study links the renewal of forest conservation legislation to the demand for increased forest exploitation. New forest policy initiatives were as much to do with pacifying conservation interests as they were about promoting ground level forest conservation.

Based on 16 months of ethnographic fieldwork between September 2011 and December 2013 in rural Yunnan, this dissertation explores the political and technical project of making water available to human use in a time of drought and environmental stress. In particular, it focuses on the collective challenge undertaken by people in this part of China to keep the water flowing through their land and their communities against many and diverse odds. The main questions it addresses are: How is water shortage experienced and confronted by Chinese citizens? How is water circulated among different people and what kind of cultural practices and institutions do they create in the attempt to meet this very basic human need? What kind of social relationships and relationships with the environment ensue from this attempt? What does it take to keep the water flowing in present day, environmentally degraded rural China? The overarching argument of the dissertation is that if fresh water still remains available in north-eastern Yunnan, this is not solely thanks to State policies or to the rational strategies adopted by public and private entities, but more significantly to the commitment of ordinary villagers and local officials who are doing their best to keep flourishing in what has now become a water-poor area. Because water keeps running thanks largely to the technical knowledge and dedication of ordinary people, it can be said that its management has a human dimension. Relationships of care and dependence, but also of mistrust and antagonism, are implicated in the active project of distributing and allocating fresh water for human use, inflecting the modalities and direction of its course. Securing water for human consumption is, above all else, a cooperative project: one pursued by people who are differently positioned across the social spectrum. By committing to this project, they also tighten and sustain human relationships, and envision the possibilities of a differently organised society in which water could be available to all.

This thesis contains five studies that make use of non-market valuation techniques and of data collected in Mexico to make methodological and policy contributions to the field. In the order that they are presented in the thesis these are: * a contingent valuation study, based on data collected face-to-face of a representative sample of the population of Mexico City, to calculate a value of statistical life for Mexico and make an assessment of whether the benefit-transfer values that have been and continue to be used in the country are appropriate for policy-making; * a study that uses data collected online on whether the type of organisation sponsoring a contingent valuation survey affects the amount participants say they are willing to pay for the good being valued (in this case mortality risk reductions), all else equal; * a study that uses the same dataset to consider the relationship between trust in institutions and other forms of social capital and contingent valuation results; * an hedonic pricing analysis that makes use of several datasets (including high-resolution property data that is not in the public domain) and seeks to improve on previous attempts at applying this method in a developing country context (jointly using spatial econometrics and an instrumental variables approach); and * a short study on whether there is a relationship between air quality, social capital and subjective wellbeing in Mexico City.

Cement -based solidification/stabilisation (s/s) has been applied to the disposal of heavy metal bearing contaminated soil and wastes for approximately 50 years. This work studies the interactions of cement and heavy metals and provides further insight into encapsulation of heavy metals in cement matrices. The pastes and suspensions of calcium oxide, calcium hydroxide, pure cement phases ( 38, C}A, C4AF, Ci 2A7 and CA) and Portland cement with or without heavy metals (Zn2+ , Pb2+, Cu2+ and Cr3+) were examined by a number of analytical techniques. These techniques were X-ray powder diffraction (XRD), solid state magic angle spinning/nuclear magnetic resonance (MAS/NMR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), differential thermal analysis (DTA) and thermogravimetry (TG). Thermodynamic modelling using a geochemical code, PHREEQC, and the edited database, was carried out to elucidate the chemical reactions occurring in cement/heavy metal systems. Heavy metals acted as accelerators for hydration of CaO, CaS and Portland cement except that Zn2+ retarded the early-age hydration of Cfi and Portland cement. This work confirmed that the precipitation of portlandite was retarded due to the hydrolysis of heavy metals. Calcium ions resulting from the decomposition of cement phases combined with heavy metals to form calcium-heavy metal double hydroxides, including CaZn2(OH)6.2H2O, Ca2(OH)4Cu(OH)2.mH2O and Ca2Cr(OH)7 .3H2O. The carbonation of CaS and Portland cement resulted in the formation of calcium carbonate and the condensation of silicates from single tetrahedra to branching sites and three-dimensional frameworks (low Ca/Si ratio C-S-H gel). The polymerisation of C-S-H gel, and the polymorphism conversion and decomposition temperature of calcium carbonate were influenced by heavy metals. The incorporation of heavy metal cations in C-S-H gel is similar to that seen in glass. Heavy metals acted as network modifiers or network intermediates. In hydrated Portland cement pastes, aluminium was partitioned in ettringite or calcium carboaluminate. After carbonation, this work revealed that aluminium was in the tetrahedral form, forming mixed AlCVSiC^ branching or three-dimensional networks. This thesis presents the new structural models for C-S-H gel and the chemical mechanisms of 38 reactions with water and carbon dioxide in the presence or absence of heavy metals. In the absence of gypsum, the reaction products detected in the pastes of C3A, C4AF, Ci2A? and CA were gehlenite hydrate, calcium carboaluminate, C4AH X and hydrogarnet. Heavy metals, especially Zn 2+ , inhibited the formation of hydrogarnet and promoted the conversion of C-A-H to calcium carboaluminate and calcium carbonate. In the presence of gypsum, the major hydration product of C^A was ettringite. During carbonation, COs'" substituted for SO 4 2 " and formed calcium carboaluminate, and eventually transformed into calcium carbonate and gibbsite. The conversion of metastable calcium carbonate polymorphs (aragonite and vaterite) to calcite through Ostwald ripening occurred very slowly in the carbonated pastes containing gypsum. The reactivity of C 3 A, C^Ay, CA and C4AF during carbonation was much lower than seen during hydration. Heavy metals influenced the rates and products of hydration or carbonation of CsA, Ci2A7, CA and C4 AF and were completely incorporated in the reaction products of these phases. Thermodynamic modelling confirmed that accelerated carbonation could be beneficially employed to cement-based s/s to improve its effectiveness. Calculations of solubility and equilibrium phase assemblage are consistent with the experimental examination obtained in this work.