Estimating Global “Blue Carbon” Emissions from Conversion and Degradation of Vegetated Coastal Ecosystems

Recent attention has focused on the high rates of annual carbon sequestration in vegetated coastal ecosystems—marshes, mangroves, and seagrasses—that may be lost with habitat destruction (‘conversion’). Relatively unappreciated, however, is that conversion of these coastal ecosystems also impacts very large pools of previously-sequestered carbon. Residing mostly in sediments, this ‘blue carbon’ can be released to the atmosphere when these ecosystems are converted or degraded. Here we provide the first global estimates of this impact and evaluate its economic implications. Combining the best available data on global area, land-use conversion rates, and near-surface carbon stocks in each of the three ecosystems, using an uncertainty-propagation approach, we estimate that 0.15–1.02 Pg (billion tons) of carbon dioxide are being released annually, several times higher than previous estimates that account only for lost sequestration. These emissions are equivalent to 3–19% of those from deforestation globally, and result in economic damages of $US 6–42 billion annually. The largest sources of uncertainty in these estimates stems from limited certitude in global area and rates of land-use conversion, but research is also needed on the fates of ecosystem carbon upon conversion. Currently, carbon emissions from the conversion of vegetated coastal ecosystems are not included in emissions accounting or carbon market protocols, but this analysis suggests they may be disproportionally important to both. Although the relevant science supporting these initial estimates will need to be refined in coming years, it is clear that policies encouraging the sustainable management of coastal ecosystems could significantly reduce carbon emissions from the land-use sector, in addition to sustaining the well-recognized ecosystem services of coastal habitats.

Pedagogical Perceptions of Classroom Performance in the Teacher Evaluative Process: A Mixed Methods Study

This sequential explanatory, mixed methods research design examines the role teachers should enact in the development process of the teacher evaluation system in Louisiana. These insights will ensure teachers are catalysts in the classroom to significantly increase student achievement and allow policymakers, practitioners, and instructional leaders to direct as learned decision makers.

The War at Home

The reform of cities spaces and housing has been a key issue with campaigners on the left for more than a century. These campaigns have found allies in the work of socially committed photographers from Jacob Riis at the turn of the twentieth century to Margaret Morton and Camilo Jose Vergara today. Globally the current phase of neo-liberalism has brought its own issues to the city as ‘regeneration’ strategies dispossess the urban poor in areas that are potentially lucrative to real estate development. In this process known as ‘accumulation by dispossession’ large profits are accumulated in the process of dispossessing people of their land, rights and homes. Central to the theoretical component of this paper, is an interrogation of contemporary ideas on the production and photographic representation of urban space. The research hence questions photography’s ability to make ‘legible’ the key drivers of today’s emergent terrains and to visualize their connections to the networks of power and capital that articulate the current political economy (Sassen 2011:36). One strand here will be the ‘fleshing out’ of the cultural practices behind photographers mediating urban development (Jones 2013: 1.2). Alongside current corporate depictions historical precedents will be discussed. Photographers as far back as Charles Marville in Paris of the 1850’s have documented urban reconstruction (Kennel 2013). Often employed by those undertaking the demolition, these photographic images frequently suppress certain narratives of the unbuilding process. Acting as a propaganda tool they eliminate the impact on the lives of inhabitants or the economic realities driving the valorization of reconstruction schemes (James 2004). Reformist documentary images have also played their part in justifying large-scale urban reconstruction that involved the eventual displacement of existing communities (Rose 1997: Blaikie 2006). Focusing on the gentrification of social housing in Pendleton, Salford (Greater Manchester) the presentation will explore the artists’ own work through a critical discussion, photographic images and excerpts from site writing they’ve undertaken in the area since 2004. It asks can an alternative photographic and visual strategy provide a meaningful political counter narrative to combat persuasive corporate discourses on ‘urban revitalization’? The paper will explore strategies and techniques of witnessing and ask whether these types of record can counter neo-liberal visualizations that mediate the material transformation of city areas. Can such representations begin a critical conversation about the nature of urban change and who benefits from these transformations (Wyly 2010)? Can we develop this critical photography into a type of practice that moves beyond generalisations and talks about social relations though an ‘explicit analysis of society’ (Rosler 2004:195).

El movimiento social de 1995 en Francia contra el neoliberalismo

Las movilizaciones de noviembre-diciembre de 1995 en Francia contra el Plan Juppé fueron la primera gran revuelta en un país europeo contra el neoliberalismo. Con los trabajadores del sector público como eje de la protesta el movimiento se desplegó en base a la articulación combinada de huelgas y manifestaciones. Las reivindicaciones sectoriales se articularon en un discurso más general de defensa del servicio público y el interés general. Noviembre-diciembre de 1995 marcó el inicio de un ciclo de movilizaciones contra el neoliberalismo en Francia que testimonió su creciente pérdida de legitimidad.

'Don't stop': re-thinking the function of endings in narrative television

This thesis argues that the study of narrative television has been limited by an adherence to accepted and commonplace conceptions of endings as derived from literary theory, particularly a preoccupation with the terminus of the text as the ultimate site of cohesion, structure, and meaning. Such common conceptions of endings, this thesis argues, are largely incompatible with the realities of television’s production and reception, and as a result the study of endings in television needs to be re-thought to pay attention to the specificities of the medium. In this regard, this thesis proposes a model of intra-narrative endings, islands of cohesion, structure, and meaning located within television texts, as a possible solution to the problem of endings in television. These intra-narrative endings maintain the functionality of traditional endings, whilst also allowing for the specificities of television as a narrative medium. The first two chapters set out the theoretical groundwork, first by exploring the essential characteristics of narrative television (serialisation, fragmentation, duration, repetition, and accumulation), then by exploring the unique relationship between narrative television and the forces of contingency. These chapters also introduce the concept of intra-narrative endings as a possible solution to the problems of television’s narrative structure, and the medium’s relationship to contingency. Following on from this my three case studies examine forms of television which have either been traditionally defined as particularly resistant to closure (soap opera and the US sitcom) or which have received little analysis in terms of their narrative structure (sports coverage). Each of these case studies provides contextual material on these televisual forms, situating them in terms of their narrative structure, before moving on to analyse them in terms of my concept of intra-narrative endings. In the case of soap opera, the chapter focusses on the death of the long running character Pat Butcher in the British soap EastEnders (BBC, 1985-), while my chapter on the US sitcom focusses on the varying levels of closure that can be located within the US sitcom, using Friends (NBC, 1993-2004) as a particular example. Finally, my chapter on sports coverage analyses the BBC’s coverage of the 2012 London Olympics, and focusses on the narratives surrounding cyclists Chris Hoy and Victoria Pendleton. Each of these case studies identifies their chosen events as intra-narrative endings within larger, ongoing texts, and analyses the various ways in which they operate within those wider texts. This thesis is intended to make a contribution to the emerging field of endings studies within television by shifting the understanding of endings away from a dominant literary model which overwhelmingly focusses on the terminus of the text, to a more televisually specific model which pays attention to the particular contexts of the medium’s production and reception.

A multi-method study of the transformation of the carbonaceous skeleton of a polymer-based nanoporous carbon along the activation pathway

The change in the carbonaceous skeleton of nanoporous carbons during their activation has received limited attention, unlike its counterpart process in the presence of an inert atmosphere. Here we adopt a multi-method approach to elucidate this change in a poly(furfuryl alcohol)-derived carbon activated using cyclic application of oxygen saturation at 250 °C before its removal (with carbon) at 800 °C in argon. The methods used include helium pycnometry, synchrotron-based X-ray diffraction (XRD) and associated radial distribution function (RDF) analysis, transmission electron microscopy (TEM) and, uniquely, electron energy-loss spectroscopy spectrum-imaging (EELS-SI), electron nanodiffraction and fluctuation electron microscopy (FEM). Helium pycnometry indicates the solid skeleton of the carbon densifies during activation from 78% to 93% of graphite. RDF analysis, EELS-SI, and FEM all suggest this densification comes through an in-plane growth of sp2 carbon out to the medium range without commensurate increase in order normal to the plane. This process could be termed ‘graphenization’. The exact way in which this process occurs is not clear, but TEM images of the carbon before and after activation suggest it may come through removal of the more reactive carbon, breaking constraining cross-links and creating space that allows the remaining carbon material to migrate in an annealing-like process.

Raman spectroscopy study of the transformation of the carbonaceous skeleton of a polymer-based nanoporous carbon along the thermal annealing pathway

We report a multi-wavelength Raman spectroscopy study of the structural changes along the thermal annealing pathway of a poly(furfuryl alcohol) (PFA) derived nanoporous carbon (NPC). The Raman spectra were deconvoluted utilizing G, D, D′, A and TPA bands. The appropriateness of these deconvolutions was confirmed via recovery of the correct dispersive behaviours of these bands. It is proposed that the ID/IG ratio is composed of two parts: one associated with the extent of graphitic crystallites (the Tuinstra–Koenig relationship), and a second related to the inter-defect distance. This model was used to successfully determine the variation of the in-plane size and intra-plane defect density along the annealing pathway. It is proposed that the NPC skeleton evolves along the annealing pathway in two stages: below 1600 °C it was dominated by a reduction of in-plane defects with a minor crystallite growth, and above this temperature growth of the crystallites accelerates as the in-plane defect density approaches zero. A significant amount of transpolyacetylene (TPA)-like structures was found to be remaining even at 2400 °C. These may be responsible for resistance to further graphitization of the PFA-based carbon at higher temperatures.

Control of the spatial homogeneity of pore surface chemistry in particulate activated carbon

We show here that a physical activation process that is diffusion-controlled yields an activated carbon whose chemistry – both elemental and functional – varies radially through the particles. For the ∼100 μm particles considered here, diffusion-controlled activation in CO2 at 800 °C saw a halving in the oxygen concentration from the particle periphery to its center. It was also observed that this activation process leads to an increase in keto and quinone groups from the particle periphery towards the center and the inverse for other carbonyls as well as ether and hydroxyl groups, suggesting the two are formed under CO2-poor and -rich environments, respectively. In contrast to these observations, use of physical activation processes where diffusion-control is absent are shown to yield carbons whose chemistry is radially invariant. This suggests that a non-diffusion limited activation processes should be used if the performance of a carbon is dependent on having a specific optimal pore surface chemical composition.

Pore size distributions derived from adsorption isotherms, immersion calorimetry, and isosteric heats: A comparative study

We compare the pore size distribution of a well-characterized activated carbon derived from model-dependent, adsorption integral equation (AIE) methods with those from model-independent, immersion calorimetry and isosteric heat analyses. The AIE approach applied to nitrogen gave a mean pore width of 0.57 nm; the CO2 distribution exhibited wider dispersion. Spherical model application to CO2 and diffusion limitations for nitrogen and argon were proposed as primary reasons for inconsistency. Immersion enthalpy revealed a sharp decrease in available area equivalent to a cut-off due to molecular exclusion when the accessible surface was assessed against probe kinetic diameter. Mean pore width was identified as 0.58 ± 0.02 nm, endorsing the underlying assumptions for the nitrogen-based AIE approach. A comparison of the zero-coverage isosteric heat of adsorption for various non-polar adsorptives by the porous test sample was compared with the same adsorptives in contact with a non-porous reference adsorbent, leading to an energy ratio or adsorption enhancement factor. A linear relationship between the energy ratio and probe kinetic diameter indicated a primary pore size at 0.59 nm. The advantage of this enthalpy, model-independent methods over AIE were due to no assumptions regarding probe molecular shape, and no assumptions for pore shape and/or connectivity.