Adapting to Climate Change in Africa

The intersection of present vulnerability and the prospect of climate change in Africa warrants proactive action now to reduce the risk of large-scale, adverse impacts. The process of planning adaptive strategies requires a systematic evaluation of priorities and constraints, and the involvement of stakeholders. An overview of climate change in Africa and case studies of impacts for agriculture and water underlie discussion of a typology of adaptive responses that may be most effective for different stakeholders. The most effective strategies are likely to be to reduce present vulnerability and to enhance a broad spectrum of capacity in responding to environmental, resource and economic perturbations. In some cases, such as design of water systems, an added risk factor should be considered.     

Fabrication and Characterization of Biodegradable Composite Films Made of Using Poly(caprolactone) Reinforced with Chitosan

Chitosan was dissolved in 2?% aqueous acetic acid solution and the films were prepared by solution casting. Values of tensile strength (TS), tensile modulus (TM), elongation at break (Eb?%) and water vapor permeability (WVP) of the chitosan films were found to be 30?MPa, 450?MPa, 8?% and 4.7?g?mm/m²?day?kPa, respectively. Poly(caprolactone) (PCL) films were prepared from its granules by compression molding and the values of TS, TM, Eb and WVP were 14?MPa, 220?MPa, 70?% and 1.54?g?mm/m²?day?kPa, respectively. PCL was reinforced with chitosan films, and composite films were prepared by compression molding. Amount of chitosan in the composite films varied from 10 to 50?% (w/w). It was found that with the incorporation of chitosan films in PCL, both the values of TS and TM of composite films increased significantly. The highest mechanical properties were found at 50?% (w/w) of chitosan content. The Oxygen transmission rate (OTR) of composite film was found to decrease significantly than PCL films. Thermal properties of the composite were also improved as compared to PCL. The water uptake test of the composite also showed promising results with a good stability of composite films. The interface of the composite was investigated by scanning electron microscopy and showed good interfacial adhesion between PCL and chitosan films.     

A guide towards climate change adaptation in the livestock sector: adaptation options and the role of robust decision-making tools for their economic appraisal

Economic appraisal and technical effectiveness of adaptation options are key criteria for judging climate change adaptation investment decisions in all sectors. Yet relatively little methodological guidance exists for determining the most appropriate appraisal techniques for different adaptation options. This paper provides adaptation options and scopes relevant appraisal methods in agriculture focussing on livestock production specifically. We find that for many adaptation options for livestock agriculture, standard (expected) cost-benefit analysis is an appropriate tool. For adaptation options requiring long lead times or those with long lifetimes, techniques incorporating uncertainty (‘robust’ methods) are more suitable, including real options analysis, portfolio analysis and robust decision-making. From a comprehensive list of adaptation options in the livestock sector, we identify the most appropriate appraisal technique for each option and describe how the robust appraisal tools could be applied to heat stress, flood risk and water management.

     

Effects of nano-TiO(2) in combination with ambient UV-irradiation on a leaf shredding amphipod

Production and use of engineered nanoparticles, such as titanium dioxide nanoparticles (nTiO₂), is increasing worldwide, enhancing their probability to enter aquatic environments. However, direct effects of nTiO₂ as well as ecotoxicological consequences due to the interactions of nTiO₂ with environmental factors like ultraviolet (UV) irradiation on representatives of detrital food webs have not been assessed so far. Hence, the present study displayed for the first time adverse sublethal effects of nTiO₂ at concentrations as low as 0.2 mg L⁻¹ on the leaf shredding amphipod Gammarus fossarum both in presence and absence of ambient UV-irradiation following a 7-d exposure. In absence of UV-irradiation, however, the effects seemed to be driven by accumulation of nTiO₂ at the bottom of the test vessels to which the gammarids were potentially exposed. The adverse sublethal and lethal effects on gammarids caused by the combined application of nTiO₂ and ambient UV-irradiation are suggested to be driven by the formation of reactive oxygen species. In conclusion, both the accumulation of nTiO₂ at the bottom of the test vessel and the UV induced formation of reactive oxygen species clearly affected its ecotoxicity, which is recommended for consideration in the environmental risk assessment of nanoparticles.     

Integrating larval connectivity into the marine conservation decision-making process across spatial scales

Larval dispersal connectivity is typically integrated into spatial conservation decisions at regional or national scales, but implementing agencies struggle with translating these methods to local scales. We used larval dispersal connectivity at regional (hundreds of kilometers) and local (tens of kilometers) scales to aid in design of networks of no-take reserves in Southeast Sulawesi, Indonesia. We used Marxan with Connectivity informed by biophysical larval dispersal models and remotely sensed coral reef habitat data to design marine reserve networks for 4 commercially important reef species across the region. We complemented regional spatial prioritization with decision trees that combined network-based connectivity metrics and habitat quality to design reserve boundaries locally. Decision trees were used in consensus-based workshops with stakeholders to qualitatively assess site desirability, and Marxan was used to identify areas for subsequent network expansion. Priority areas for protection and expected benefits differed among species, with little overlap in reserve network solutions. Because reef quality varied considerably across reefs, we suggest reef degradation must inform the interpretation of larval dispersal patterns and the conservation benefits achievable from protecting reefs. Our methods can be readily applied by conservation practitioners, in this region and elsewhere, to integrate connectivity data across multiple spatial scales.     

Steady‐state field‐scale gas permeability estimation and pore‐gas velocity calculation in a domain open to the atmosphere

Field‐scale estimation of gas permeability and subsequent computation of pore‐gas velocity profiles are critical elements of sound soil venting design. It has been our experience, however, in U.S. Environmental Protection Agency's (EPA's) technical assistance program, provided by the Office of Research and Development in support EPA regional offices, that many venting practitioners are unaware of equations and data interpretation methods appropriate for gas permeability estimation and pore‐gas velocity computation. To ameliorate this situation, we use data collected at a U.S. Coast Guard Station in Traverse City, Michigan, to demonstrate gets permeability estimation and pore‐gas velocity calculation for steady‐state, axisymmetric, two‐dimensional gas flow in a domain open to the atmosphere. For gas permeability estimation, we use random guesses constrained with decreasing intervals of radial and vertical permeabilityand analysis of root mean square errors to ensure attainment of a global versus local minimum. We demonstrate confidence in permeability estimation by providing plots of observed versus simulated pressure response. Finally, we illustrate how plots of pore‐gas velocity as a function of distance and flow rate can be helpful in venting design.     

Belief Networks: A Framework for the Participatory Development of Natural Resource Management Strategies

Successful long-term management of natural resources requires the development of strategies which recognise the constraints pertaining to the environmental system and can therefore be realistically expected to work. This paper presents a new technique for strategy formulation using belief networks, a framework based on Bayesian probability calculus that supports the investigation of complex environmental systems by the user and analysis of all constraints. While mathematical in nature, belief networks are superficially simple and allow concepts to be expressed in terms with which a wide range of user will be familiar. This offers a participatory approach to the development of management strategies through consideration of the impact of potential management options with consequent benefits for strategy implementation.     

Pinch analysis approach to carbon-constrained planningfor sustainable power generation

A graphical pinch-based methodology for planning retrofits for carbon capture and storage (CCS) in the power generation sector is presented in this work. CCS is widely seen as one of the essential interim technologies to mitigate greenhouse gas emissions, while still being able to utilize fossil fuels, which are relatively inexpensive and reliable in comparison to inherently low-carbon renewable resources. However, retrofitting power plants for CCS entails major capital costs as well as a reduction of thermal efficiency and power output. Thus, it is essential for planning purposes to implement the minimal extent of CCS retrofit that meets the sectoral carbon footprint targets. At the same time, it is necessary to plan for additional power generation capacity or efficiency enhancements to compensate for energy losses resulting from CCS retrofits. The simple graphical approach used in this paper is designed to determine such targets, and shares the same intuitive, insight-driven characteristics of pinch analysis techniques. A case study is shown to illustrate the methodology.