118 research outputs found
Biofuels in the world markets: A Computable General Equilibrium assessment of environmental costs related to land use changes
Biofuels in the world markets: A Computable General Equilibrium assessment of environmental costs related to land use changes
Algoritmo Genético e Algoritmo de Vaga-lumes aplicados ao Problema do Caixeiro Viajante
Trabalho de Conclusão de Curso (Graduação)Os algoritmos de otimização computacional são amplamente aplicados em diversas áreas, computacionais e do mundo real, para encontrar soluções ou aproximações das mesmas de problemas complexos. Os algoritmos de otimização estudados neste trabalho são: o Algoritmo Genético (AG) e o Algoritmo de Vaga-lumes (AVL). Esses algoritmos são bioinspirados, isto é, se baseiam em processos que ocorrem na natureza. Ambos os métodos foram utilizados para encontrar uma solução ótima, ou aproximação, para o Problema do Caixeiro Viajante (PCV), caracterizado como um problema NP por sua alta complexidade. O PCV é deĄnido como um problema de busca de um percurso em um grafo, partindo-se de um vértice inicial e visitando cada um dos outros vértices uma única vez e retornando ao ponto de partida. Portanto, este trabalho teve como objetivo principal um estudo do AG e AVL usando o PCV como problema alvo por sua complexidade e sua facilidade em relacioná-lo com diversos problemas do mundo real. O estudo foi realizado por meio do desenvolvimento dos métodos e da execução de experimentos com instâncias obtidas da biblioteca TSPLIB
L’avenir de l’élevage africain : Réaliser le potentiel de l’élevage pour la sécurité alimentaire, la réduction de la pauvreté et la protection de l’environnement en Afrique sub- saharienne
Carbon prices, climate change mitigation & food security: How to avoid trade-offs?
Carbon price policies deliver cost-efficient mitigation across sectors, but can result in tradeoffs with food security and other sustainable development goals. Scenarios for a 1.5 °C world based on carbon prices could increase the undernourished population by 80 - 300 million in 2050. Applying a uniform carbon price across geographic regions and economic sectors has inequitable effects on countries’ agricultural competitiveness and food availability. Under higher carbon prices, regions with poor productivity – and consequently higher GHG emissions per unit of output – would experience increased agricultural commodity prices
Climate Change Effects on Agriculture: Economic Responses to Biophysical Shocks
Agricultural production is sensitive to weather and thus directly affected by climate change. Plausible estimates of these climate change impacts require combined use of climate, crop, and economic models. Results from previous studies vary substantially due to differences in models, scenarios, and data. This paper is part of a collective effort to systematically integrate these three types of models. We focus on the economic component of the assessment, investigating how nine global economic models of agriculture represent endogenous responses to seven standardized climate change scenarios produced by two climate and five crop models. These responses include adjustments in yields, area, consumption, and international trade. We apply biophysical shocks derived from the Intergovernmental Panel on Climate Change's representative concentration pathway with end-of-century radiative forcing of 8.5 W/m(sup 2). The mean biophysical yield effect with no incremental CO2 fertilization is a 17% reduction globally by 2050 relative to a scenario with unchanging climate. Endogenous economic responses reduce yield loss to 11%, increase area of major crops by 11%, and reduce consumption by 3%. Agricultural production, cropland area, trade, and prices show the greatest degree of variability in response to climate change, and consumption the lowest. The sources of these differences include model structure and specification; in particular, model assumptions about ease of land use conversion, intensification, and trade. This study identifies where models disagree on the relative responses to climate shocks and highlights research activities needed to improve the representation of agricultural adaptation responses to climate change
Reducing greenhouse gas emissions in agriculture without compromising food security?
To keep global warming possibly below 1.5◦C and mitigate adverse effects of climate change, agriculture, like all other sectors, will have to contribute to efforts in achieving net negative emissions by the end of the century. Cost-efficient distribution of mitigation across regions and economic sectors is typically calculated using a global uniform carbon price in climate stabilization scenarios. However, in reality such a carbon price would substantially affect food availability. Here, we assess the implications of climate change mitigation in the land use sector for agricultural production and food security using an integrated partial equilibrium modelling framework and explore ways of relaxing the competition between mitigation in agriculture and food availability. Using a scenario that limits global warming cost-efficiently across sectors to 1.5◦C, results indicate global food calorie losses ranging from 110–285 kcal per capita per day in 2050 depending on the applied demand elasticities. This could translate into a rise in undernourishment of 80–300 million people in 2050. Less ambitious greenhouse gas (GHG) mitigation in the land use sector reduces the associated food security impact significantly, however the 1.5◦C target would not be achieved without additional reductions outside the land use sector. Efficiency of GHG mitigation will also depend on the level of participation globally. Our results show that if non-Annex-I countries decide not to contribute to mitigation action while other parties pursue their mitigation efforts to reach the global climate target, food security impacts in these non-Annex-I countries will be higher than if they participate in a global agreement, as inefficient mitigation increases agricultural production costs and therefore food prices. Land-rich countries with a high proportion of emissions from land use change, such as Brazil, could reduce emissions with only a marginal effect on food availability. In contrast, agricultural mitigation in high population (density) countries, such as China and India, would lead to substantial food calorie loss without a major contribution to global GHG mitigation. Increasing soil carbon sequestration on agricultural land would allow reducing the implied calorie loss by 65% when sticking to the initially estimated land use mitigation requirements, thereby limiting the impact on undernourishment to 20–75 million people, and storing significant amounts of carbon in soils
Greenhouse gas mitigation potentials in the livestock sector
Acknowledgements This paper constitutes an output of the Belmont Forum/FACCE-JPI funded DEVIL project (NE/M021327/1). Financial support from the CGIAR Program on Climate Change, Agriculture and Food Security (CCAFS) and the EU-FP7 AnimalChange project is also recognized. P.K.T. acknowledges the support of a CSIRO McMaster Research Fellowship.Peer reviewedPostprin
Challenges of Global Agriculture in a Climate Change Context by 2050 (AgCLIM50)
This report presents a global integrated assessment of the range of potential economic impacts of climate change and stringent mitigation measures in the agricultural sector. The analysis employs five global multi-region multi-commodity models and covers selected combinations of socioeconomic storylines and climate signals by mid-century. Model inputs are harmonised by using the same projections for population and GDP growth, as well as relative biophysical crop yield changes due to climate change. Model results can differ depending on model characteristics and the specific quantitative implementations of the socioeconomic storylines.JRC.D.4-Economics of Agricultur
The future of food security, environments and livelihoods in Western Africa: Four socio-economic scenarios
This working paper examines the development of regional socioeconomic scenarios for West Africa’s development, agriculture, food security and climate impacts. We present four globally consistent regional scenarios framed and outlined by regional experts who crafted narratives and determined key drivers of change. Stakeholders identified the type of actors driving change and the timeline of strategic planning as the most uncertain and most relevant factors of change affecting food security, livelihoods and environments in the region.
The scenarios were linked to the IPCC community’s global Shared Socio-economic Pathways (SSPs) and quantified using two agricultural economic models, GLOBIOM and IMPACT, in interaction with drivers outlined by the SSPs and guided by semi-quantitative information from the stakeholders. The quantification of the scenarios has provided additional insights into the possible development of Western Africa in the context of a global economy as well as how the agricultural sector may be affected by climate change. The scenarios process highlights the need to combine socio-economic and climate scenarios, to base these scenarios in regional expertise, and ways to make scenarios useful for policy design.
The objective of this working paper is to provide scenarios for future regional development for West Africa on the future of food security, environment, and rural livelihoods as well as offer details of the multi-stakeholder scenarios development process. Using both qualitative and quantitative scenarios we provide insights into the possible development of West Africa as well as a scalable framework for regional decision makers and the scientific community to use scenarios to build and test policies to make them more robust in the face of future uncertainty.
In these scenarios, strong economic development increases food security and agricultural development. Increased crop and livestock productivity may lead to an expansion of agricultural areas within the region but productivity improvements may reduce the pressure on land elsewhere. In the context of a global economy, West Africa remains a large consumer and producer of a selection of commodities. However, the growth in population in combination with rising incomes may lead to increases in the region’s imports. For West Africa, climate change is likely to have negative effects on both crop yields and grassland productivity, and lack of investment in agriculture may exacerbate them.
The aim of the regional scenarios is provide challenging contexts for policy makers to test and develop a range of national and regional policies. To date, the scenarios have been used in a number of policy design processes which include collaborations with ECOWAS priority setting, the National Plan for the Rural Sector for Burkina Faso (PNSR), and district and national level policy processes in Ghana
Динамические тенденции в становлении предмета лингвоэкологии
Экологизация всех сфер общественной жизни и самого человека широко обсуждается во многих наука, а также и в области языка. Во многих работах лингвистов экология языка определяется как наука о
взаимоотношениях между языком и его окружением, так как язык существует не только в сознании говорящих на нем и функционирует только при взаимоотношениях с другими коммуникантами и с их
социальным и природным окружением. В этом контексте понятие «языковое сознание» представляет собой специфическую картину взаимосвязи культуры и общественной жизни социума, которая определяет его психологическое своеобразие и специфические черты данного языка
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