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1.
Nature ; 517(7533): 187-90, 2015 Jan 08.
Artículo en Inglés | MEDLINE | ID: mdl-25567285

RESUMEN

Policy makers have generally agreed that the average global temperature rise caused by greenhouse gas emissions should not exceed 2 °C above the average global temperature of pre-industrial times. It has been estimated that to have at least a 50 per cent chance of keeping warming below 2 °C throughout the twenty-first century, the cumulative carbon emissions between 2011 and 2050 need to be limited to around 1,100 gigatonnes of carbon dioxide (Gt CO2). However, the greenhouse gas emissions contained in present estimates of global fossil fuel reserves are around three times higher than this, and so the unabated use of all current fossil fuel reserves is incompatible with a warming limit of 2 °C. Here we use a single integrated assessment model that contains estimates of the quantities, locations and nature of the world's oil, gas and coal reserves and resources, and which is shown to be consistent with a wide variety of modelling approaches with different assumptions, to explore the implications of this emissions limit for fossil fuel production in different regions. Our results suggest that, globally, a third of oil reserves, half of gas reserves and over 80 per cent of current coal reserves should remain unused from 2010 to 2050 in order to meet the target of 2 °C. We show that development of resources in the Arctic and any increase in unconventional oil production are incommensurate with efforts to limit average global warming to 2 °C. Our results show that policy makers' instincts to exploit rapidly and completely their territorial fossil fuels are, in aggregate, inconsistent with their commitments to this temperature limit. Implementation of this policy commitment would also render unnecessary continued substantial expenditure on fossil fuel exploration, because any new discoveries could not lead to increased aggregate production.


Asunto(s)
Combustibles Fósiles/provisión & distribución , Combustibles Fósiles/estadística & datos numéricos , Geografía , Calentamiento Global/prevención & control , Calentamiento Global/estadística & datos numéricos , Regiones Árticas , Atmósfera/química , Dióxido de Carbono/análisis , Carbón Mineral/economía , Carbón Mineral/estadística & datos numéricos , Carbón Mineral/provisión & distribución , Bases de Datos Factuales , Combustibles Fósiles/economía , Efecto Invernadero/prevención & control , Efecto Invernadero/estadística & datos numéricos , Modelos Teóricos , Yacimiento de Petróleo y Gas , Factores de Tiempo
3.
Enterp Soc ; 12(4): 790-823, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22213886

RESUMEN

Home heating and lighting markets have played crucial and underappreciated roles in driving energy transitions. When historians have studied the adoption of fossil fuels, they have often privileged industrial actors, markets, and technologies. My analysis of the factors that stimulated the adoption of anthracite coal and petroleum during the nineteenth century reveals that homes shaped how, when, and why Americans began to use fossil fuel energy. Moreover, a brief survey of other fossil fuel transitions shows that heating and lighting markets have been critical drivers in other times and places. Reassessing the historical patterns of energy transitions offers a revised understanding of the past for historians and suggests a new set of options for policymakers seeking to encourage the use of renewable energy in the future.


Asunto(s)
Carbón Mineral , Economía , Vivienda , Petróleo , Salud Pública , Energía Renovable , Características de la Residencia , Carbono/economía , Carbono/historia , Carbón Mineral/economía , Carbón Mineral/historia , Economía/historia , Economía/legislación & jurisprudencia , Combustibles Fósiles/economía , Combustibles Fósiles/historia , Historia del Siglo XIX , Historia del Siglo XX , Productos Domésticos/economía , Productos Domésticos/historia , Vivienda/economía , Vivienda/historia , Vivienda/legislación & jurisprudencia , Petróleo/economía , Petróleo/historia , Salud Pública/economía , Salud Pública/educación , Salud Pública/historia , Salud Pública/legislación & jurisprudencia , Energía Renovable/economía , Energía Renovable/historia , Energía Renovable/legislación & jurisprudencia , Características de la Residencia/historia , Estados Unidos/etnología
4.
Environ Sci Technol ; 43(13): 4763-75, 2009 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-19673263

RESUMEN

In this paper, we assess what is known or anticipated about environmental and sustainability factors associated with next-generation biofuels relative to the primary conventional biofuels (i.e., corn grain-based ethanol and soybean-based diesel) in the United States during feedstock production and conversion processes. Factors considered include greenhouse (GHG) emissions, air pollutant emissions, soil health and quality, water use and water quality, wastewater and solid waste streams, and biodiversity and land-use changes. Based on our review of the available literature, we find that the production of next-generation feedstocks in the U.S. (e.g., municipal solid waste, forest residues, dedicated energy crops, microalgae) are expected to fare better than corn-grain or soybean production on most of these factors, although the magnitude of these differences may vary significantly among feedstocks. Ethanol produced using a biochemical or thermochemical conversion platform is expected to result in fewer GHG and air pollutant emissions, but to have similar or potentially greater water demands and solid waste streams than conventional ethanol biorefineries in the U.S. However, these conversion-related differences are likely to be small, particularly relative to those associated with feedstock production. Modeling performed for illustrative purposes and to allow for standardized quantitative comparisons across feedstocks and conversion technologies generally confirms the findings from the literature. Despite current expectations, significant uncertainty remains regarding how well next-generation biofuels will fare on different environmental and sustainability factors when produced on a commercial scale in the U.S. Additional research is needed in several broad areas including quantifying impacts, designing standardized metrics and approaches, and developing decision-support tools to identify and quantify environmental trade-offs and ensure sustainable biofuels production.


Asunto(s)
Fuentes Generadoras de Energía , Monitoreo del Ambiente/métodos , Combustibles Fósiles/economía , Agricultura , Contaminantes Atmosféricos , Alimentación Animal , Ambiente , Contaminantes Ambientales , Etanol/química , Gasolina , Efecto Invernadero , Petróleo , Glycine max , Emisiones de Vehículos , Contaminantes del Agua
6.
Environ Sci Technol ; 42(20): 7559-65, 2008 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-18983075

RESUMEN

Liquid transportation fuels derived from coal and natural gas could helpthe United States reduce its dependence on petroleum. The fuels could be produced domestically or imported from fossil fuel-rich countries. The goal of this paper is to determine the life-cycle GHG emissions of coal- and natural gas-based Fischer-Tropsch (FT) liquids, as well as to compare production costs. The results show that the use of coal- or natural gas-based FT liquids will likely lead to significant increases in greenhouse gas (GHG) emissions compared to petroleum-based fuels. In a best-case scenario, coal- or natural gas-based FT-liquids have emissions only comparable to petroleum-based fuels. In addition, the economic advantages of gas-to-liquid (GTL) fuels are not obvious: there is a narrow range of petroleum and natural gas prices at which GTL fuels would be competitive with petroleum-based fuels. CTLfuels are generally cheaper than petroleum-based fuels. However, recent reports suggest there is uncertainty about the availability of economically viable coal resources in the United States. If the U.S. has a goal of increasing its energy security, and at the same time significantly reducing its GHG emissions, neither CTL nor GTL consumption seem a reasonable path to follow.


Asunto(s)
Química Orgánica/métodos , Carbón Mineral/economía , Combustibles Fósiles/economía , Efecto Invernadero , Gasolina , Petróleo , Transportes , Volatilización
7.
Proc Natl Acad Sci U S A ; 103(30): 11206-10, 2006 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-16837571

RESUMEN

Negative environmental consequences of fossil fuels and concerns about petroleum supplies have spurred the search for renewable transportation biofuels. To be a viable alternative, a biofuel should provide a net energy gain, have environmental benefits, be economically competitive, and be producible in large quantities without reducing food supplies. We use these criteria to evaluate, through life-cycle accounting, ethanol from corn grain and biodiesel from soybeans. Ethanol yields 25% more energy than the energy invested in its production, whereas biodiesel yields 93% more. Compared with ethanol, biodiesel releases just 1.0%, 8.3%, and 13% of the agricultural nitrogen, phosphorus, and pesticide pollutants, respectively, per net energy gain. Relative to the fossil fuels they displace, greenhouse gas emissions are reduced 12% by the production and combustion of ethanol and 41% by biodiesel. Biodiesel also releases less air pollutants per net energy gain than ethanol. These advantages of biodiesel over ethanol come from lower agricultural inputs and more efficient conversion of feedstocks to fuel. Neither biofuel can replace much petroleum without impacting food supplies. Even dedicating all U.S. corn and soybean production to biofuels would meet only 12% of gasoline demand and 6% of diesel demand. Until recent increases in petroleum prices, high production costs made biofuels unprofitable without subsidies. Biodiesel provides sufficient environmental advantages to merit subsidy. Transportation biofuels such as synfuel hydrocarbons or cellulosic ethanol, if produced from low-input biomass grown on agriculturally marginal land or from waste biomass, could provide much greater supplies and environmental benefits than food-based biofuels.


Asunto(s)
Fuentes Generadoras de Energía/economía , Etanol/economía , Combustibles Fósiles/economía , Agricultura/economía , Agricultura/métodos , Contaminantes Atmosféricos , Contaminación del Aire , Biomasa , Ambiente , Gasolina , Humanos , Petróleo , Glycine max , Emisiones de Vehículos
8.
Environ Sci Technol ; 36(24): 5289-95, 2002 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-12521152

RESUMEN

Environmental taxes have attracted attention in recent years as a tool to internalize environmental externalities. This paper evaluates Sweden's experience with environmental taxes in the energy sector by examining how environmental taxes compare with estimated environmental externalities associated with the use of oil, coal, natural gas, and forest residue fuels. We also analyze how environmental taxes influence fuel choices in the energy sector by comparing the production, environmental, and tax costs for the same fuels. We find that (i) the Swedish environmental taxes correspond imperfectly with environmental costs; (ii) the Swedish tax and subsidy system introduces changes in fuel choice decisions; (iii) the energy users are responding to the incentives created by the tax and subsidy systems in ways that are consistent with economic theory; and (iv) the Swedish experience with environmental taxes and subsidies bears directly on wider evaluations of energy policy approaches internationally.


Asunto(s)
Ambiente , Impuestos/economía , Carbón Mineral/economía , Conservación de los Recursos Energéticos/métodos , Combustibles Fósiles/economía , Petróleo/economía , Suecia , Árboles
10.
Lancet ; 339(8805): 1330-3, 1992 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-1349998

RESUMEN

PIP: The Earth is a finite environment, thus growth cannot occur indefinitely. Eventually we will run out of space, resources, or anything else that is also finite. Once this fact is recognized, it becomes clear that we must develop in a sustainable way so that we can endure into the future. Overpopulation, vegetation destruction, and pollution are all serious threats to our finite environment. Traditionally, change has been to expensive and politically destabilizing. However, extensive changes in our modes of living must be made so that they become sustainable. In both developed and developing countries, consumptive growth must be replaced with sustainable development. Many developing countries are currently selling their natural resources to the developed countries. When they run out of resources, they will be truly poor. All governments must recognize the value of forests. It is estimated that in terms of medical uses for forest products alone, they will be worth US$11-12 billion (1990 dollars) by 2050. This constitutes a large portion of developing countries economies. Also, 80% of the population of developing countries rely on natural, traditional medicines made from forest products. Even in the US 25% of prescription drugs are based on phytochemicals. Now the drug companies are actively pursuing these resources for their products. It is estimated that 95% of the world species have not been assayed for their chemical value. Technology and money are not the obstacles to sustainable development and forest conservation. It is will and attitude that must be radically changed in order to protect the forests for the ecological and economic value.^ieng


Asunto(s)
Economía/tendencias , Salud Ambiental , Salud Global , Árboles , Agricultura , Brasil , Países en Desarrollo , Predicción , Combustibles Fósiles/economía , Combustibles Fósiles/normas , Humanos , Plantas Medicinales , Crecimiento Demográfico , Especificidad de la Especie
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