Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 32
Filtrar
1.
Nature ; 572(7769): 373-377, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31261374

RESUMO

Net anthropogenic emissions of carbon dioxide (CO2) must approach zero by mid-century (2050) in order to stabilize the global mean temperature at the level targeted by international efforts1-5. Yet continued expansion of fossil-fuel-burning energy infrastructure implies already 'committed' future CO2 emissions6-13. Here we use detailed datasets of existing fossil-fuel energy infrastructure in 2018 to estimate regional and sectoral patterns of committed CO2 emissions, the sensitivity of such emissions to assumed operating lifetimes and schedules, and the economic value of the associated infrastructure. We estimate that, if operated as historically, existing infrastructure will cumulatively emit about 658 gigatonnes of CO2 (with a range of 226 to 1,479 gigatonnes CO2, depending on the lifetimes and utilization rates assumed). More than half of these emissions are predicted to come from the electricity sector; infrastructure in China, the USA and the 28 member states of the European Union represents approximately 41 per cent, 9 per cent and 7 per cent of the total, respectively. If built, proposed power plants (planned, permitted or under construction) would emit roughly an extra 188 (range 37-427) gigatonnes CO2. Committed emissions from existing and proposed energy infrastructure (about 846 gigatonnes CO2) thus represent more than the entire carbon budget that remains if mean warming is to be limited to 1.5 degrees Celsius (°C) with a probability of 66 to 50 per cent (420-580 gigatonnes CO2)5, and perhaps two-thirds of the remaining carbon budget if mean warming is to be limited to less than 2 °C (1,170-1,500 gigatonnes CO2)5. The remaining carbon budget estimates are varied and nuanced14,15, and depend on the climate target and the availability of large-scale negative emissions16. Nevertheless, our estimates suggest that little or no new CO2-emitting infrastructure can be commissioned, and that existing infrastructure may need to be retired early (or be retrofitted with carbon capture and storage technology) in order to meet the Paris Agreement climate goals17. Given the asset value per tonne of committed emissions, we suggest that the most cost-effective premature infrastructure retirements will be in the electricity and industry sectors, if non-emitting alternatives are available and affordable4,18.


Assuntos
Dióxido de Carbono/análise , Eletricidade , Combustíveis Fósseis/provisão & distribuição , Aquecimento Global/prevenção & controle , Objetivos , Cooperação Internacional/legislação & jurisprudência , Temperatura , Atmosfera/química , Combustíveis Fósseis/economia , Aquecimento Global/economia , Gás Natural/provisão & distribuição
2.
Nature ; 554(7691): 229-233, 2018 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-29420477

RESUMO

Hopes are high that removing fossil fuel subsidies could help to mitigate climate change by discouraging inefficient energy consumption and levelling the playing field for renewable energy. In September 2016, the G20 countries re-affirmed their 2009 commitment (at the G20 Leaders' Summit) to phase out fossil fuel subsidies and many national governments are using today's low oil prices as an opportunity to do so. In practical terms, this means abandoning policies that decrease the price of fossil fuels and electricity generated from fossil fuels to below normal market prices. However, whether the removal of subsidies, even if implemented worldwide, would have a large impact on climate change mitigation has not been systematically explored. Here we show that removing fossil fuel subsidies would have an unexpectedly small impact on global energy demand and carbon dioxide emissions and would not increase renewable energy use by 2030. Subsidy removal would reduce the carbon price necessary to stabilize greenhouse gas concentration at 550 parts per million by only 2-12 per cent under low oil prices. Removing subsidies in most regions would deliver smaller emission reductions than the Paris Agreement (2015) climate pledges and in some regions global subsidy removal may actually lead to an increase in emissions, owing to either coal replacing subsidized oil and natural gas or natural-gas use shifting from subsidizing, energy-exporting regions to non-subsidizing, importing regions. Our results show that subsidy removal would result in the largest CO2 emission reductions in high-income oil- and gas-exporting regions, where the reductions would exceed the climate pledges of these regions and where subsidy removal would affect fewer people living below the poverty line than in lower-income regions.


Assuntos
Comércio/economia , Comércio/estatística & dados numéricos , Financiamento Governamental/economia , Financiamento Governamental/tendências , Combustíveis Fósseis/economia , Combustíveis Fósseis/estatística & dados numéricos , Aquecimento Global/prevenção & controle , Dióxido de Carbono/análise , Eletricidade , Financiamento Governamental/legislação & jurisprudência , Aquecimento Global/legislação & jurisprudência , Renda/estatística & dados numéricos , Cooperação Internacional , Pobreza/economia , Pobreza/estatística & dados numéricos
12.
Environ Sci Technol ; 45(7): 3160-6, 2011 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-21375280

RESUMO

Wind power can make an important contribution to the goal of reducing emissions of CO2. The major problem relates to the intrinsic variability of the source and the difficulty of reconciling the supply of electricity with demand particularly at high levels of wind penetration. This challenge is explored for the case of the ERCOT system in Texas. Demand for electricity in Texas is projected to increase by approximately 60% by 2030. Considering hourly load data reported for 2006, assuming that the pattern of demand in 2030 should be similar to 2006, and adopting as a business as usual (BAU) reference an assumption that the anticipated additional electricity should be supplied by a combination of coal and gas with prices, discounted to 2007 dollars of $2 and $6 per MMBTU respectively, we conclude that the bus-bar price for electricity would increase by about 1.1 ¢/kWh at a wind penetration level of 30%, by about 3.4 ¢/kWh at a penetration level of 80%. Corresponding costs for reductions in CO2 range from $20/ton to $60/ton. A number of possibilities are discussed that could contribute to a reduction in these costs including the impact of an expanded future fleet of electrically driven vehicles.


Assuntos
Poluentes Atmosféricos/economia , Poluição do Ar/economia , Dióxido de Carbono/economia , Fontes Geradoras de Energia/economia , Centrais Elétricas/economia , Vento , Poluentes Atmosféricos/análise , Poluição do Ar/prevenção & controle , Poluição do Ar/estatística & dados numéricos , Dióxido de Carbono/análise , Pegada de Carbono/economia , Pegada de Carbono/estatística & dados numéricos , Conservação dos Recursos Naturais/economia , Fontes Geradoras de Energia/estatística & dados numéricos , Combustíveis Fósseis/economia , Texas
14.
PLoS One ; 15(10): e0239634, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33021990

RESUMO

In recent years, the environmental problems caused by excessive carbon emissions from energy sources have become increasingly serious, which not only aggravates the climate change caused by the greenhouse effect but also seriously restricts the sustainable development of Chinese economy. An attempt is made in this paper to use energy consumption method and input-output method to study the carbon emission structure of China's energy system and industry in 2015 from two perspectives, namely China's energy supply side and energy demand side, by taking into account the two factors of energy invest in gross capital formation and export. The results show that neglecting these two factors will lead to underestimation of intermediate use carbon emissions and overestimation of final use carbon emissions. On energy supply side, the carbon emission structure of China's energy system is still dominated by high-carbon energy (raw coal, coke, diesel, and fuel oil, etc.), accounting for more than 70% of total energy carbon emissions; on the contrary, the natural gas such as clean energy accounts for only 3.45% of total energy carbon emissions, indicating that the energy consumption structure optimization and emission reduction gap of China's energy supply side are still substantial. On energy demand side, the final use (direct consumption by residents and government) produces less carbon emissions, while the intermediate use (production by enterprises) produces more than 90% of the total energy carbon emissions. Fossil energy, power sector, heavy industry, chemical industry, and transportation belong to industries with larger carbon emissions and lower carbon emission efficiency, while agriculture, construction, light industry, and service belong to industries with fewer carbon emissions and higher carbon emission efficiency. This means that the optimization of industrial structure is conducive to slowing down the growth of energy carbon emissions on the demand side.


Assuntos
Pegada de Carbono/economia , Desenvolvimento Econômico , Combustíveis Fósseis , Aquecimento Global/economia , Carbono/análise , China , Mudança Climática/economia , Carvão Mineral/economia , Fontes Geradoras de Energia/economia , Poluição Ambiental/economia , Poluição Ambiental/prevenção & controle , Combustíveis Fósseis/economia , Aquecimento Global/prevenção & controle , Efeito Estufa/economia , Efeito Estufa/prevenção & controle , Humanos , Indústrias/economia , Investimentos em Saúde
15.
Nat Commun ; 11(1): 5172, 2020 10 14.
Artigo em Inglês | MEDLINE | ID: mdl-33057164

RESUMO

The COVID-19 pandemic is impacting human activities, and in turn energy use and carbon dioxide (CO2) emissions. Here we present daily estimates of country-level CO2 emissions for different sectors based on near-real-time activity data. The key result is an abrupt 8.8% decrease in global CO2 emissions (-1551 Mt CO2) in the first half of 2020 compared to the same period in 2019. The magnitude of this decrease is larger than during previous economic downturns or World War II. The timing of emissions decreases corresponds to lockdown measures in each country. By July 1st, the pandemic's effects on global emissions diminished as lockdown restrictions relaxed and some economic activities restarted, especially in China and several European countries, but substantial differences persist between countries, with continuing emission declines in the U.S. where coronavirus cases are still increasing substantially.


Assuntos
Poluentes Atmosféricos/análise , Dióxido de Carbono/análise , Infecções por Coronavirus/epidemiologia , Pneumonia Viral/epidemiologia , Poluentes Atmosféricos/economia , Betacoronavirus , COVID-19 , Dióxido de Carbono/economia , Infecções por Coronavirus/economia , Infecções por Coronavirus/prevenção & controle , Monitoramento Ambiental , Combustíveis Fósseis/análise , Combustíveis Fósseis/economia , Humanos , Indústrias/economia , Dióxido de Nitrogênio/análise , Dióxido de Nitrogênio/economia , Pandemias/economia , Pandemias/prevenção & controle , Pneumonia Viral/economia , Pneumonia Viral/prevenção & controle , SARS-CoV-2
16.
Caring ; 27(8): 44-7, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18795535

RESUMO

The rapidly rising cost of fuel has had a profound impact on the home care and hospice industry. In an effort to quantify the increased burden, the National Association for Home Care & Hospice's (NAHC) Foundation for Hospice and Home Care conducted a study showing that home care and hospice providers drive over 5 billion miles per year to deliver services --about two-and-a-half times the number driven by United Parcel Service, the international delivery service. The findings garnered significant interest by the media and elected officials. Reprinted in this issue of CARING Magazine are the press release that NAHC issued regarding the study, as well as a graphic representation of the study's findings that was circulated to the National Conference of State Legislatures at its most recent meeting in July. Also represented on these pages is a reprint from the Congressional Record of July 11, 2008, in which Senator Debbie Stabenow (D-MI), one of the highest ranking Democrats in the US. Senate, entered into the record an article from the front page of the New York Times of July 5, 2008, that covered the mileage study.


Assuntos
Combustíveis Fósseis/economia , Serviços de Assistência Domiciliar/economia , Pacientes Domiciliares , Visita Domiciliar/economia , Viagem/economia , Idoso , Condução de Veículo , Estado Terminal/economia , Estado Terminal/terapia , Serviços de Saúde para Idosos/economia , Cuidados Paliativos na Terminalidade da Vida/economia , Humanos , Viagem/estatística & dados numéricos , Estados Unidos
17.
Health Aff (Millwood) ; 37(3): 504-507, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29505375

RESUMO

Being unable to meet basic household energy needs can have dire health consequences and merits more attention and resources.


Assuntos
Eletricidade , Características da Família , Combustíveis Fósseis/economia , Nível de Saúde , Pobreza , Saúde Pública , Feminino , Calefação/métodos , Humanos , Política Pública
19.
PLoS One ; 10(5): e0124074, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25970621

RESUMO

There is an ongoing debate about the deployment rates and composition of alternative energy plans that could feasibly displace fossil fuels globally by mid-century, as required to avoid the more extreme impacts of climate change. Here we demonstrate the potential for a large-scale expansion of global nuclear power to replace fossil-fuel electricity production, based on empirical data from the Swedish and French light water reactor programs of the 1960s to 1990s. Analysis of these historical deployments show that if the world built nuclear power at no more than the per capita rate of these exemplar nations during their national expansion, then coal- and gas-fired electricity could be replaced worldwide in less than a decade. Under more conservative projections that take into account probable constraints and uncertainties such as differing relative economic output across regions, current and past unit construction time and costs, future electricity demand growth forecasts and the retiring of existing aging nuclear plants, our modelling estimates that the global share of fossil-fuel-derived electricity could be replaced within 25-34 years. This would allow the world to meet the most stringent greenhouse-gas mitigation targets.


Assuntos
Combustíveis Fósseis/economia , Energia Nuclear/economia , Centrais Elétricas/provisão & distribuição , Dióxido de Carbono/química , Mudança Climática , Eletricidade , Combustíveis Fósseis/estatística & dados numéricos , França , Efeito Estufa/prevenção & controle , Humanos , Energia Nuclear/estatística & dados numéricos , Suécia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA