1,724 research outputs found
A Perspective Paper on Forestry Carbon Sequestration as a Response to Climate Change
I find myself in broad agreement with Brent Sohngen's analysis of costs and benefits associated with the climate change mitigation options offered by forest carbon sequestration, which includes afforestation, reductions in deforestation (REDD) and forest management. In this paper, I intend to summarize the assessment paper's approach and conclusions, highlight the most important findings, identify gaps and their implications for the calculations and thus put the results into perspective. The areas dealt with concern competition for land and its potential impact of opportunity costs, the role of various types of uncertainty and their implications for implementing forestry carbon sequestration programs, the effect of accounting for ecosystems services and biodiversity on benefit assessments, and the relevance of option values in considering REDD strategies. The conclusion drawn from the analysis coincides with the findings of Sohngen, who claims that forest carbon will be needed as part of a strategy to mitigate climate change. Solutions can thus not arise exclusively from the technosphere, especially in the face of time and other resource constraints
Investment in Water-saving Irrigation Options under Uncertainties - A Comparative Analysis
The agricultural sector of Pakistan consumes 96 percent of the country's available fresh water resources. With a population of 187 million and increasing at an annual growth rate of 1.57 percent, the fresh water resources of the country will face severe stresses in the coming years, affecting its food security. At the same time, there is uncertainty prevailing in the region about climate change, timing and intensity of rainfall, flood and drought events, coupled with glacial melt and unresolved issues pertaining to trans-boundary water resource management. Under these circumstances, investment in agricultural practices that ensure crop productivity and water conservation are critical to Pakistan's food security. This study focuses on a sub-region of Punjab in Pakistan, where wheat is grown using flood irrigation. It examines whether an investment into water-saving irrigation options, such as canal lining, dredging, water saving irrigation technologies, and on farm water storage are feasible options to improve profits of the farmers. Irrigation in Pakistan is supplemented with low quality groundwater, which at times leads to very low yields per unit of water. By comparing the discounted cash flows under each of these options, this study investigates the best investment decisions on the part of the farmer and policy makers. This study also looks at the benefits of crop diversification and water markets, to examine whether these options would lead to higher profitability, hedging of risks and productivity in the study area. The economic analysis is complemented with real options analysis, and where applicable, sensitivity analysis to determine the minimum yield increases required to break even
Optimal forest management with stochastic prices & endogenous fire risk
Earth observations are one way to reduce the risk to standing forests from damages caused by wild fires, since they enable early warning systems, preventive actions and faster extinguishing of fires, before they spread out. Another channel through which fire hazard can be reduced is the thinning of the forest, so the risk of a fire occurring becomes partially endogenous. In order to shed more light on optimal forest management under such endogenous fire risk, we develop a real options model, where the price of biomass is stochastic and the harvesting decision needs to be timed optimally in the face of these uncertainties. We find that there is a positive value of information. In other words, there is a positive willingness to pay for Earth observations by forest managers
Human health impacts for renewable energy scenarios from the EnerGEO Platform of Integrated Assessment (PIA)
This article reports impact results from running the EnerGEO Platform of Integrated Assessment (PIA) related to human health for different scenarios in Europe. The scenarios were prepared within the EnerGEO project. The idea of this European project is to determine how low carbon scenarios, and in particular scenarios with a high share of renewable energy, affect concentrations of air pollutants and as a consequence affect human health. PM2.5 concentrations were estimated with the IIASA Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS) model on a time horizon up to the year 2050 for different scenarios. We analyse here the estimation of the Loss of Life Expectancy due to PM2.5 concentrations for the Baseline scenario taken as a reference and the Maximum renewable power scenario
The EnerGEO Platform of Integrated Assessment (PIA): Environmental assessment of scenarios as a web service
With the International Energy Agency estimating that global energy demand will increase between 40 and 50 percent by 2030 (compared to 2003), scientists and policymakers are concerned about the sustainability of the current energy system and what environmental pressures might result from the development of future energy systems. EnerGEO is an ongoing FP7 Project (2009-2013) which assesses the current and future impact of energy use on the environment by linking environmental observation systems with the processes involved in exploiting energy resources. The idea of this European project is to determine how low carbon scenarios, and in particular scenarios with a high share of renewable electricity, affect emissions of air pollutants and greenhouse gases (GHG) and contribute to mitigation of negative energy system impacts on human health and ecosystems. A Platform of Integrated Assessment (PIA) has been elaborated to provide impact results for a selection of scenarios via a set of models (large-scale energy models, Life Cycle Assessment models, ...). This PIA is currently available through a web service. The concept of the PIA is detailed and to illustrate its interest, a set of results is given with the use of the simulation mode of the European version of GAINS for a selection of scenarios
Strain measurement at the knee ligament insertion sites
We describe the modification of an existing method of ligament strain measurement at the knee joint in detail. At ten fresh joint specimens we used that technique where strain gauges are attached to the ligamentous insertions and origins. We both improved the preparation of the attachment site and the application of the strain gauges. In a special apparatus the specimens were moved from 0degrees extension to 100degrees flexion while simulating muscle strength and axial force. Testing was performed at the posterior cruciate ligament with both intact and transsected anterior cruciate ligament. In contrast to other existing techniques it does not affect the motion of the joint or the integrity and the function of the ligaments. Unlike the original description of that method we could register a loading behaviour of the posterior cruciate ligament that is similar to those reported in the literature
Integrated assessment of crop management portfolios in adapting to climate change in the Marchfeld region
Portfolio optimization is an adequate tool to find optimal crop management options in adapting to climate change. The risk farmers have to face can be caused by different sources. In our study, we focus on the risk arising from unknown weather conditions. Therefore, we developed stochastic climate change scenarios for the Marchfeld region. Two portfolio models have been applied in the time periods 2008-2020, 2021-2030 and 2031-2040: a traditional non-linear mean-variance (E-V) model and a model using the Conditional Value at Risk (CVaR) as risk metric. Investigated crops are corn, winter wheat, sunflower and spring barley with different crop management alternatives. Minimum tillage appears in all portfolios. We found a decreasing share of winter wheat that gets partially substituted by sunflower over the time periods. When including environmental constraints (soil organic carbon content, nitrate leaching) the reverse effect on the resulting portfolio shares is observed with corn being included. The E-V model reveals more diversification with respect to the crops, whereas the CVaR model shows more diversification with respect to crop management options
Food Security in an Uncertain World
Food security has been and continues to be a top priority for policymakers in a world of transformations. Even though featuring high on the agenda, insufficient progress has been made on the corresponding Millennium Development Goal in Subsaharan Africa, Southern and Western Asia and Oceania. Furthermore, increasing population and changing environmental conditions exacerbate the challenge of ensuring food security. In the long run, climate change will continue to add to this and - in addition - affect different parts of the world asymmetrically. Finally, food security is not a goal to be achieved in isolation of other factors: in fact, it is at the centre if a number of trade-offs involving issues ranging over bioenergy provision, preservation of forests and biodiversity and competition with other land uses. It is also closely linked to other resources, which are turning increasingly scarce, the prime example being water. However, while there is a common understanding of all these pressures, they remain surrounded by uncertainty and so are the socio-economic and climate scenarios, which we use to prepare strategies for achieving food security in concert with other goals. Zooming into such scenarios and their implications shows that we need to not only strive for resolving uncertainty, but also to explore robust solutions, which put us on a sustainable, yet flexible development path rather than locking us into scenarios, which we subjectively consider most likely in the face of incomplete information
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