166 research outputs found

    Forest regeneration on European sheep pasture is an economically viable climate change mitigation strategy

    Get PDF
    Livestock production uses 37% of land globally and is responsible for 15% of anthropogenic greenhouse gas emissions. Yet livestock farmers across Europe receive billions of dollars in annual subsidies to support their livelihoods. This study evaluates whether diverting European subsidies into the restoration of trees on abandoned farmland represents a cost-effective negative-emissions strategy for mitigating climate change. Focusing on sheep farming in the United Kingdom, and on natural regeneration and planted native forests, we show that, without subsidies, sheep farming is not profitable when farmers are paid for their labour. Despite the much lower productivity of upland farms, upland and lowland farms are financially comparable per hectare. Conversion to 'carbon forests' is possible via natural regeneration when close to existing trees, which are seed sources. This strategy is financially viable without subsidies, meeting the net present value of poorly performing sheep farming at a competitive 4/tCO2eq.Iftreeplantingisrequiredtoestablishforests,then 4/tCO2eq. If tree planting is required to establish forests, then ~55/tCO2eq is needed to break-even, making it uneconomical under current carbon market prices without financial aid to cover establishment costs. However, this break-even price is lower than the theoretical social value of carbon ($68/tCO2eq), which represents the economic cost of CO2 emissions to society. The viability of land-use conversion without subsidies therefore depends on low farm performance, strong likelihood of natural regeneration, and high carbon-market price, plus overcoming potential trade-offs between the cultural and social values placed on pastoral livestock systems and climate change mitigation. The morality of subsidising farming practices that cause high greenhouse gas emissions in Europe, whilst spending billions annually on protecting forest carbon in less developed nations to slow climate change is questionable

    Strength and ductility demands on wind turbine towers due to earthquake and wind load

    Get PDF
    In earthquake prone areas, wind and earthquake loads are assumed to be statistically uncorrelated, therefore their interaction is ignored by existing design guidelines. However, the fact that strong earthquake events are commonly followed by aftershocks and that wind is constantly flowing at high speeds around wind farms increase the probability of their joint occurrence, thus making current design assumptions questionable. This investigation shows that multi-hazard scenarios magnify strength demands of wind turbine towers designed against isolated load conditions, hence modifying their performance level. It is also shown that, under certain conditions, the probabilities associated to the joint occurrence of earthquake and low to strong wind events match or exceed those related to the original design, thus rendering wind energy infrastructure susceptible to unforeseen damage

    Urban neighbourhood flood vulnerability and risk assessments at different diurnal levels

    Get PDF
    Diurnal changes within communities can significantly alter the level of impacts during a flood, yet these essential daily variations are not currently catered for within flood risk assessments. This paper develops a flood vulnerability and risk model that captures crucial features of flood vulnerability; integrating physical and socio‐economic vulnerability data, combined with a flood hazard analysis, to give overall flood risk at neighbourhood scale, at two different times of day, for floods of different magnitudes. The flood vulnerability and risk model, the resulting diurnal coastal flood vulnerability and risk indexes, and corresponding maps for the ward of Hilsea (Portsmouth, United Kingdom), presented within this paper, highlight three previously unidentified neighbourhoods in particular in the northwest of the Hilsea ward, which have the highest levels of risk during both time zones and for flood events of different magnitude. Critically, these neighbourhoods lie further inland and not directly on the Hilsea coastline, yet by analysing at this resolution (including diurnal impacts), substantial levels of underlying vulnerability were identified within these areas

    Challenges for Implementing an Ecosystem Approach to Fisheries Management

    Get PDF
    The ecosystem approach is being promoted as the foundation of solutions to the unsustainability of fisheries. However, because the ecosystem approach is broadly inclusive, the science for its implementation is often considered to be overly complex and difficult. When the science needed for an ecosystem approach to fisheries is perceived this way, science products cannot keep pace with fisheries critics, thus encouraging partisan political interference in fisheries management and proliferation of “faith-based solutions. In this paper we argue that one way to effectively counter politicization of fisheries decision-making is to ensure that new ecosystem-based approaches in fisheries are viewed only as an emergent property of innovation in science and policy. We organize our essay using three major themes to focus the discussion: empirical, jurisdictional, and societal challenges. We undertake at least partial answers to the following questions: (1) has conventional fisheries management really failed?; (2) can short-comings in conventional fisheries management be augmented with new tools, such as allocation of rights?; (3) is the Ecosystem Approach to Fisheries (EAF) equivalent to Ecosystem-Based Management?; and (4) is restoration of degraded ecosystems a necessary component of an EAF

    Change in Sediment Features and the Macroinvertebrate Community Within an Estuarine Ecosystem Two Years Post‐restoration

    Get PDF
    Our objective was to assess the response of an estuarine ecosystem to restoration efforts, two years post‐restoration. Sediment attributes of particle size distribution (PSD), %LOI, water content and amounts of fine wood debris (FWD), and the macroinvertebrate community were compared among three sites, two reference and the recently restored site. The restored region had been previously used as a log sorting facility. As indicated by PSD, the restored site showed signs of recovery. However, the macroinvertebrate community had still not responded to restoration efforts. Sediments of reference sites were comprised of fine sand, and the macroinvertebrate community was dominated by Macoma spp. By contrast, at the restored site, sediments were mainly comprised of silt followed by fine sand, Macoma spp. was absent, and the main macroinvertebrate was Glycera americana, a polychaeta characteristic of disturbed regions. The restored site still contained significance amounts of FWD as compared to the two reference sites attributed to its previous use. Although still early in its recovery stage, active restoration did have a positive effect and will have likely kick started the region toward recovery and further follow‐up in five years is recommended

    Monthly record; meteorological observations in Canada. : Résumé mensuel; données météorologiques pour le Canada.

    No full text
    Supplements in June and Dec. issues contain data recieved too late for inclusion in appropriate monthly issue.Mode of access: Internet.Split into: Monthly record, meteorological observattions in western Canada, ISSN 0706-4071 ; Monthly record, meteorological observations in northern Canada, ISSN 0706-408X ; Monthly record, meteorological observations in eastern Canada, ISSN 0706-406
    corecore