O The Telegraph (Santanomics: the calculations that make it all possible for Saint Nick, Lauren Davidson) apresenta alguns cálculos interessantes sobre o trabalho que Papai Noel terá na noite de natal. Calculando 1,85 bilhão de crianças no mundo entre zero e catorze anos (além de 1,2 bilhão entre 15 e 24) e supondo dois presentes por criança, a tarefa de Papai Noel será enorme:
1 – Serão 3,7 bilhões de presentes
2 – Supondo que cada elfo gaste oito segundos para embrulhar um presente, Papai Noel precisa de três mil elfos para, trabalhando oito horas por dia no ano, fazer a tarefa gastando 300 bilhões de centímetros de papel, o que corresponde a 7,5 vezes a distância da Terra à lua.
3 – Supondo que os presentes sejam a boneca do Frozen e o relógio VTech, cada criança receberia 47 libras de presente. Isto corresponde a 87 bilhões de libras ou 362 bilhões de reais. Só de papel de presente seriam 6,2 bilhões de reais.
4 – Para entregar os presentes, supondo 2,5 crianças por residência, isto representaria 740 milhões de chaminés. Como Noel dispõe de 32 horas para fazer o trabalho (graças ao fuso horário) seria necessário 390 mil casas por minuto ou 6.424 por segundo.
Bom Trabalho, Papai Noel.
24 dezembro 2014
Ascensão e declínio das Leis Gerais do Capitalismo
Abstract:
Thomas Piketty's (2014) book, Capital in the 21st Century, follows in the tradition of the great classical economists, like Marx and Ricardo, in formulating general laws of capitalism to diagnose and predict the dynamics of inequality. We argue that general economic laws are unhelpful as a guide to understand the past or predict the future, because they ignore the central role of political and economic institutions, as well as the endogenous evolution of technology, in shaping the distribution of resources in society. We use regression evidence to show that the main economic force emphasized in Piketty's book, the gap between the interest rate and the growth rate, does not appear to explain historical patterns of inequality (especially, the share of income accruing to the upper tail of the distribution). We then use the histories of inequality of South Africa and Sweden to illustrate that inequality dynamics cannot be understood without embedding economic factors in the context of economic and political institutions, and also that the focus on the share of top incomes can give a misleading characterization of the true nature of inequality.
Autores: Daron Acemoglu (MIT) e James Robinson(Harvard)
Artigo Completo:The Rise and Decline of General Laws of Capitalism
Eike: autuação da Receita
O empresário Eike Batista recebeu uma autuação da Receita Federal no valor de R$ 172,6 milhões, referente a débito que não teria sido pago de Imposto de Renda (IR), segundo informações publicadas neste domingo pelo jornal Folha de S.Paulo. O IR não pago refere-se a ganhos de capital, obtidos com venda de ações, participações societárias ou imóveis, durante o ano de 2011.
De acordo com a Folha, a investigação foi iniciada em 2013 e concluída há seis meses. Todo contribuinte deve pagar IR sobre lucro obtido com as operações – a alíquota é de 15%. No caso de ações, vai a 20% se os papéis tiverem sido comprados no mesmo dia.
Segundo especialista consultado pela Folha, considerando o período em que ocorreram as negociações que originaram o débito, e os juros incidentes desde então, é possível estimar que metade da dívida, cerca de R$ 86 milhões, seja referente a imposto não pago em ganho de capital. O resto seria atribuído à cobrança de multa e de juros.
Eike recorreu da autuação, e o caso agora virou um processo administrativo fiscal. Se perder em primeira instância, o empresário poderá parcelar a dívida ou recorrer no Conselho Administrativo de Recursos Fiscais) Carf. Caso não pague o débito nem recorra, a dívida será encaminhada à Procuradoria da Fazenda Nacional e ele será inscrito na dívida ativa da União, com cobrança judicial, que poderá levar a penhora e leilão de bens para quitação do passivo, de acordo com a Folha.
A reportagem falou com o advogado do empresário, que afirmou que Eike está inacessível, no exterior.
Fonte: Aqui
De acordo com a Folha, a investigação foi iniciada em 2013 e concluída há seis meses. Todo contribuinte deve pagar IR sobre lucro obtido com as operações – a alíquota é de 15%. No caso de ações, vai a 20% se os papéis tiverem sido comprados no mesmo dia.
Segundo especialista consultado pela Folha, considerando o período em que ocorreram as negociações que originaram o débito, e os juros incidentes desde então, é possível estimar que metade da dívida, cerca de R$ 86 milhões, seja referente a imposto não pago em ganho de capital. O resto seria atribuído à cobrança de multa e de juros.
Eike recorreu da autuação, e o caso agora virou um processo administrativo fiscal. Se perder em primeira instância, o empresário poderá parcelar a dívida ou recorrer no Conselho Administrativo de Recursos Fiscais) Carf. Caso não pague o débito nem recorra, a dívida será encaminhada à Procuradoria da Fazenda Nacional e ele será inscrito na dívida ativa da União, com cobrança judicial, que poderá levar a penhora e leilão de bens para quitação do passivo, de acordo com a Folha.
A reportagem falou com o advogado do empresário, que afirmou que Eike está inacessível, no exterior.
Fonte: Aqui
Princesa Cristina e o Fisco Espanhol
Agora um juiz espanhol decidiu que a princesa seja julgada pelas acusações de fraude fiscal. Há um mês o juiz tinha decidido que a princesa seria suspeita num caso que envolve o seu marido. Uma entidade sem fins lucrativos, comandada pelo marido de Cristina, desviou recursos públicos, num total que pode chegar a 6 milhões de euros.
Além disto, a corte ordenou que a princesa deposite 2,6 milhões de euros, conforme informou a Reuters. O julgamento está ocorrendo em Maiorca.
Salário do Papai Noel
"Fico bravo quando me perguntam quanto o Papai Noel recebe", diz Sílvio Ribeiro, que dá aulas sobre como ser Papai Noel. "Por que não perguntam para o [médico] Drauzio Varella quanto ele ganha quando entrevistam ele?".
Vida de Papai Noel no Natal não é fácil e a remuneração varia bastante. Pode chegar a R$ 15 mil, segundo Ribeiro.
Mas isso é apenas uma parcela pequena, os que trabalham em shopping center ou participam de comerciais de TV, por exemplo. Esse valor é referente ao período todo de trabalho, que pode chegar a dois meses, e inclui benefícios, como transporte e alimentação, e sem desconto de impostos.
"Depois aparecem interessados no meu curso achando que é só ter barba que vão ganhar R$ 15 mil. Quando digo que alguma loja está contratando por R$ 1.200 para trabalhar seis a oito horas por dia durante duas semanas, desistem".
Ribeiro se intitula o Papai Noel mais antigo em atividade no Brasil. Ele começou há 47 anos, quando tinha 18, e nunca mais parou. Ele montou sua agência, a Claus Produções Artísticas, que ministra cursos desde 1976. Perdeu a conta de quantos alunos já teve, mas foram "pelo menos 1.200".
Os preços para contratar o serviço também são diversos. A Papai Noel e Cia, outra agência natalina, oferece 25 tipos de atração, desde a visita do bom velhinho até elaboradas produções cênicas, que podem custar de R$ 1.000 a R$ 7.000.
[...]
Vida de Papai Noel no Natal não é fácil e a remuneração varia bastante. Pode chegar a R$ 15 mil, segundo Ribeiro.
Mas isso é apenas uma parcela pequena, os que trabalham em shopping center ou participam de comerciais de TV, por exemplo. Esse valor é referente ao período todo de trabalho, que pode chegar a dois meses, e inclui benefícios, como transporte e alimentação, e sem desconto de impostos.
"Depois aparecem interessados no meu curso achando que é só ter barba que vão ganhar R$ 15 mil. Quando digo que alguma loja está contratando por R$ 1.200 para trabalhar seis a oito horas por dia durante duas semanas, desistem".
Ribeiro se intitula o Papai Noel mais antigo em atividade no Brasil. Ele começou há 47 anos, quando tinha 18, e nunca mais parou. Ele montou sua agência, a Claus Produções Artísticas, que ministra cursos desde 1976. Perdeu a conta de quantos alunos já teve, mas foram "pelo menos 1.200".
Os preços para contratar o serviço também são diversos. A Papai Noel e Cia, outra agência natalina, oferece 25 tipos de atração, desde a visita do bom velhinho até elaboradas produções cênicas, que podem custar de R$ 1.000 a R$ 7.000.
[...]
Fonte: Aqui
23 dezembro 2014
22 dezembro 2014
Mestrado e Doutorado Aprovado
Acabo de receber a confirmação da aprovação do Mestrado e Doutorado em Contabilidade da Universidade de Brasília. Os programas das duas outras universidades que compunham o multi (UFRN e UFPB) também foram aprovados.
Com respeito a UnB, haverá processo seletivo no início do ano. Breve divulgarei o link para o edital.
Com respeito a UnB, haverá processo seletivo no início do ano. Breve divulgarei o link para o edital.
Aquecimento Global: Derretimento estatístico
The Global Warming Statistical Meltdown by Judith Curry
At the recent United Nations Climate Summit, Secretary-General Ban Ki-moon warned that “Without significant cuts in emissions by all countries, and in key sectors, the window of opportunity to stay within less than 2 degrees [of warming] will soon close forever.” Actually, this window of opportunity may remain open for quite some time. A growing body of evidence suggests that the climate is less sensitive to increases in carbon-dioxide emissions than policy makers generally assume—and that the need for reductions in such emissions is less urgent.
According to the U.N. Framework Convention on Climate Change, preventing “dangerous human interference” with the climate is defined, rather arbitrarily, as limiting warming to no more than 2 degrees Celsius (3.6 degrees Fahrenheit) above preindustrial temperatures. The Earth’s surface temperatures have already warmed about 0.8 degrees Celsius since 1850-1900. This leaves 1.2 degrees Celsius (about 2.2 degrees Fahrenheit) to go.
In its most optimistic projections, which assume a substantial decline in emissions, the Intergovernmental Panel on Climate Change (IPCC) projects that the “dangerous” level might never be reached. In its most extreme, pessimistic projections, which assume heavy use of coal and rapid population growth, the threshold could be exceeded as early as 2040. But these projections reflect the effects of rising emissions on temperatures simulated by climate models, which are being challenged by recent observations.
Human-caused warming depends not only on increases in greenhouse gases but also on how “sensitive” the climate is to these increases. Climate sensitivity is defined as the global surface warming that occurs when the concentration of carbon dioxide in the atmosphere doubles. If climate sensitivity is high, then we can expect substantial warming in the coming century as emissions continue to increase. If climate sensitivity is low, then future warming will be substantially lower, and it may be several generations before we reach what the U.N. considers a dangerous level, even with high emissions.
The IPCC’s latest report (published in 2013) concluded that the actual change in 70 years if carbon-dioxide concentrations double, called the transient climate response, is likely in the range of 1 to 2.5 degrees Celsius. Most climate models have transient climate response values exceeding 1.8 degrees Celsius. But the IPCC report notes the substantial discrepancy between recent observation-based estimates of climate sensitivity and estimates from climate models.
Nicholas Lewis and I have just published a study in Climate Dynamics that shows the best estimate for transient climate response is 1.33 degrees Celsius with a likely range of 1.05-1.80 degrees Celsius. Using an observation-based energy-balance approach, our calculations used the same data for the effects on the Earth’s energy balance of changes in greenhouse gases, aerosols and other drivers of climate change given by the IPCC’s latest report.
We also estimated what the long-term warming from a doubling of carbon-dioxide concentrations would be, once the deep ocean had warmed up. Our estimates of sensitivity, both over a 70-year time-frame and long term, are far lower than the average values of sensitivity determined from global climate models that are used for warming projections. Also our ranges are narrower, with far lower upper limits than reported by the IPCC’s latest report. Even our upper limits lie below the average values of climate models.
Our paper is not an outlier. More than a dozen other observation-based studies have found climate sensitivity values lower than those determined using global climate models, including recent papers published in Environmentrics (2012),Nature Geoscience (2013) and Earth Systems Dynamics (2014). These new climate sensitivity estimates add to the growing evidence that climate models are running “too hot.” Moreover, the estimates in these empirical studies are being borne out by the much-discussed “pause” or “hiatus” in global warming—the period since 1998 during which global average surface temperatures have not significantly increased.
This pause in warming is at odds with the 2007 IPCC report, which expected warming to increase at a rate of 0.2 degrees Celsius per decade in the early 21st century. The warming hiatus, combined with assessments that the climate-model sensitivities are too high, raises serious questions as to whether the climate-model projections of 21st century temperatures are fit for making public policy decisions.
The sensitivity of the climate to increasing concentrations of carbon dioxide is a central question in the debate on the appropriate policy response to increasing carbon dioxide in the atmosphere. Climate sensitivity and estimates of its uncertainty are key inputs into the economic models that drive cost-benefit analyses and estimates of the social cost of carbon.
Continuing to rely on climate-model warming projections based on high, model-derived values of climate sensitivity skews the cost-benefit analyses and estimates of the social cost of carbon. This can bias policy decisions. The implications of the lower values of climate sensitivity in our paper, as well as similar other recent studies, is that human-caused warming near the end of the 21st century should be less than the 2-degrees-Celsius “danger” level for all but the IPCC’s most extreme emission scenario.
This slower rate of warming—relative to climate model projections—means there is less urgency to phase out greenhouse gas emissions now, and more time to find ways to decarbonize the economy affordably. It also allows us the flexibility to revise our policies as further information becomes available.
First draft
I learned a lot about writing an op-ed through this process. Below is my first draft. This morphed into the final version based on input from Nic, another journalist and another person who is experienced in writing op-eds, plus input from the WSJ editors. All of the words in the final version have been approved by me, although the WSJ editors chose the title.
The challenge is to simplify the language, but not the argument, and keep it interesting and relevant while at the same not distorting the information. Below is my first draft:
Some insensitivity about climate change
At the recent UN Climate Summit, Secretary-General Ban-Ki Moon stated: “Without significant cuts in emissions by all countries, and in key sectors, the window of opportunity to stay within less than 2 degrees will soon close forever.”
In the context of the UN Framework Convention on Climate Change, preventing ‘dangerous human interference’ with the climate has been defined – rather arbitrarily – as limiting warming to more than 2oC above preindustrial temperatures. The Earth’s surface temperatures have already warmed about 0.8oC, leaving only 1.2oC before reaching allegedly ‘dangerous’ levels. Based upon global climate model simulations, the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5; 2013) projects a further increase in global mean surface temperatures with continued emissions to exceed 1.2oC sometime within the 21st century, with the timing and magnitude of the exceedance depending on future emissions.
If and when we reach this dangerous level of human caused warming depends not only on how quickly emissions rise, but also on the sensitivity of the climate to greenhouse gas induced warming. If climate sensitivity is high, then we can expect substantial warming in the coming century if greenhouse gas emissions continue to increase. If climate sensitivity is low, then future warming will be substantially lower.
Climate sensitivity is the global surface warming that occurs when the concentration of carbon dioxide in the atmosphere doubles. Equilibrium climate sensitivity refers to the rise in temperature once the climate system has fully warmed up, a process taking centuries due to the enormous heat capacity of the ocean. Transient climate response is a shorter-term measure of sensitivity, over a 70 year timeframe during which carbon dioxide concentrations double.
The IPCC AR5 concluded that equilibrium climate sensitivity is likely in the range 1.5°C to 4.5°C and the transient climate response is likely in the range of 1.0°C to 2.5°C. Climate model simulations produce values in the upper region of these ranges, with most climate models having equilibrium climate sensitivity values exceeding 3.5oC and transient climate response values exceeding 1.8oC.
At the lower end of the sensitivity ranges reported by the IPCC AR5 are values of the climate sensitivity determined using an energy budget model approach that matches global surface temperatures with greenhouse gas concentrations and other forcings (such as solar variations and aerosol forcings) over the last century or so. I coauthored a paper recently published in Climate Dynamics that used this approach to determine climate sensitivity. Our calculations used the same forcing data given by the IPCC AR5, and we included a detailed accounting of the impact of uncertainties in the forcing data on our climate sensitivity estimates.
Our results show the best (median) estimate for equilibrium climate sensitivity is 1.64oC, with a likely (17–83% probability) range of 1.25–2.45oC. The median estimate for Transient Climate Response is 1.33oC with a likely range of 10.5-1.80oC. Most significantly, our new results support narrower likely ranges for climate sensitivity with far lower upper limits than reported by the IPCC AR5. Our upper limits lie below – for equilibrium climate sensitivity, substantially below – the average values of climate models used for warming projections. The true climate sensitivity may even be lower, since the energy budget model assumes that all climate change is forced, and does not account for the effects of decadal and century scale internal variability associated with long-term ocean oscillations.
These new climate sensitivity estimates adds to the growing evidence that climate models are running ‘too hot.’ At the heart of the recent scientific debate on climate change is the ‘pause’ or ‘hiatus’ in global warming – the period since 1998 during which global average surface temperatures have not increased. This observed warming hiatus contrasts with the expectation from the 2007 IPCC Fourth Assessment Report that warming would proceed at a rate of 0.2oC/per decade in the early decades of the 21st century. The warming hiatus combined with assessments that the climate model sensitivities are too high raises serious questions as to whether the climate model projections of 21st century have much utility for decision making.
The sensitivity of our climate to increasing concentrations of carbon dioxide is at the heart of the public debate on the appropriate policy response to increasing carbon dioxide in the atmosphere. Climate sensitivity and estimates of its uncertainty are key inputs into the economic models that drive cost-benefit analyses and estimates of the social cost of carbon.
Continuing to use the higher global climate model-derived values of climate sensitivity skews the cost-benefit analyses and estimates of the social cost of carbon. The implications of the lower values of climate sensitivity in our paper is that human caused warming near the end of the 21st century should be less than the 2oC ‘danger’ level for all but the most extreme emission scenario considered by the IPCC AR5. This delay in the warming – relative to climate model projections – relaxes the phase out period for greenhouse gas emissions, allowing more time to find ways to decarbonize the economy affordably and the flexibility to revise our policies as further information becomes available.
At the recent United Nations Climate Summit, Secretary-General Ban Ki-moon warned that “Without significant cuts in emissions by all countries, and in key sectors, the window of opportunity to stay within less than 2 degrees [of warming] will soon close forever.” Actually, this window of opportunity may remain open for quite some time. A growing body of evidence suggests that the climate is less sensitive to increases in carbon-dioxide emissions than policy makers generally assume—and that the need for reductions in such emissions is less urgent.
According to the U.N. Framework Convention on Climate Change, preventing “dangerous human interference” with the climate is defined, rather arbitrarily, as limiting warming to no more than 2 degrees Celsius (3.6 degrees Fahrenheit) above preindustrial temperatures. The Earth’s surface temperatures have already warmed about 0.8 degrees Celsius since 1850-1900. This leaves 1.2 degrees Celsius (about 2.2 degrees Fahrenheit) to go.
In its most optimistic projections, which assume a substantial decline in emissions, the Intergovernmental Panel on Climate Change (IPCC) projects that the “dangerous” level might never be reached. In its most extreme, pessimistic projections, which assume heavy use of coal and rapid population growth, the threshold could be exceeded as early as 2040. But these projections reflect the effects of rising emissions on temperatures simulated by climate models, which are being challenged by recent observations.
Human-caused warming depends not only on increases in greenhouse gases but also on how “sensitive” the climate is to these increases. Climate sensitivity is defined as the global surface warming that occurs when the concentration of carbon dioxide in the atmosphere doubles. If climate sensitivity is high, then we can expect substantial warming in the coming century as emissions continue to increase. If climate sensitivity is low, then future warming will be substantially lower, and it may be several generations before we reach what the U.N. considers a dangerous level, even with high emissions.
The IPCC’s latest report (published in 2013) concluded that the actual change in 70 years if carbon-dioxide concentrations double, called the transient climate response, is likely in the range of 1 to 2.5 degrees Celsius. Most climate models have transient climate response values exceeding 1.8 degrees Celsius. But the IPCC report notes the substantial discrepancy between recent observation-based estimates of climate sensitivity and estimates from climate models.
Nicholas Lewis and I have just published a study in Climate Dynamics that shows the best estimate for transient climate response is 1.33 degrees Celsius with a likely range of 1.05-1.80 degrees Celsius. Using an observation-based energy-balance approach, our calculations used the same data for the effects on the Earth’s energy balance of changes in greenhouse gases, aerosols and other drivers of climate change given by the IPCC’s latest report.
We also estimated what the long-term warming from a doubling of carbon-dioxide concentrations would be, once the deep ocean had warmed up. Our estimates of sensitivity, both over a 70-year time-frame and long term, are far lower than the average values of sensitivity determined from global climate models that are used for warming projections. Also our ranges are narrower, with far lower upper limits than reported by the IPCC’s latest report. Even our upper limits lie below the average values of climate models.
Our paper is not an outlier. More than a dozen other observation-based studies have found climate sensitivity values lower than those determined using global climate models, including recent papers published in Environmentrics (2012),Nature Geoscience (2013) and Earth Systems Dynamics (2014). These new climate sensitivity estimates add to the growing evidence that climate models are running “too hot.” Moreover, the estimates in these empirical studies are being borne out by the much-discussed “pause” or “hiatus” in global warming—the period since 1998 during which global average surface temperatures have not significantly increased.
This pause in warming is at odds with the 2007 IPCC report, which expected warming to increase at a rate of 0.2 degrees Celsius per decade in the early 21st century. The warming hiatus, combined with assessments that the climate-model sensitivities are too high, raises serious questions as to whether the climate-model projections of 21st century temperatures are fit for making public policy decisions.
The sensitivity of the climate to increasing concentrations of carbon dioxide is a central question in the debate on the appropriate policy response to increasing carbon dioxide in the atmosphere. Climate sensitivity and estimates of its uncertainty are key inputs into the economic models that drive cost-benefit analyses and estimates of the social cost of carbon.
Continuing to rely on climate-model warming projections based on high, model-derived values of climate sensitivity skews the cost-benefit analyses and estimates of the social cost of carbon. This can bias policy decisions. The implications of the lower values of climate sensitivity in our paper, as well as similar other recent studies, is that human-caused warming near the end of the 21st century should be less than the 2-degrees-Celsius “danger” level for all but the IPCC’s most extreme emission scenario.
This slower rate of warming—relative to climate model projections—means there is less urgency to phase out greenhouse gas emissions now, and more time to find ways to decarbonize the economy affordably. It also allows us the flexibility to revise our policies as further information becomes available.
First draft
I learned a lot about writing an op-ed through this process. Below is my first draft. This morphed into the final version based on input from Nic, another journalist and another person who is experienced in writing op-eds, plus input from the WSJ editors. All of the words in the final version have been approved by me, although the WSJ editors chose the title.
The challenge is to simplify the language, but not the argument, and keep it interesting and relevant while at the same not distorting the information. Below is my first draft:
Some insensitivity about climate change
At the recent UN Climate Summit, Secretary-General Ban-Ki Moon stated: “Without significant cuts in emissions by all countries, and in key sectors, the window of opportunity to stay within less than 2 degrees will soon close forever.”
In the context of the UN Framework Convention on Climate Change, preventing ‘dangerous human interference’ with the climate has been defined – rather arbitrarily – as limiting warming to more than 2oC above preindustrial temperatures. The Earth’s surface temperatures have already warmed about 0.8oC, leaving only 1.2oC before reaching allegedly ‘dangerous’ levels. Based upon global climate model simulations, the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5; 2013) projects a further increase in global mean surface temperatures with continued emissions to exceed 1.2oC sometime within the 21st century, with the timing and magnitude of the exceedance depending on future emissions.
If and when we reach this dangerous level of human caused warming depends not only on how quickly emissions rise, but also on the sensitivity of the climate to greenhouse gas induced warming. If climate sensitivity is high, then we can expect substantial warming in the coming century if greenhouse gas emissions continue to increase. If climate sensitivity is low, then future warming will be substantially lower.
Climate sensitivity is the global surface warming that occurs when the concentration of carbon dioxide in the atmosphere doubles. Equilibrium climate sensitivity refers to the rise in temperature once the climate system has fully warmed up, a process taking centuries due to the enormous heat capacity of the ocean. Transient climate response is a shorter-term measure of sensitivity, over a 70 year timeframe during which carbon dioxide concentrations double.
The IPCC AR5 concluded that equilibrium climate sensitivity is likely in the range 1.5°C to 4.5°C and the transient climate response is likely in the range of 1.0°C to 2.5°C. Climate model simulations produce values in the upper region of these ranges, with most climate models having equilibrium climate sensitivity values exceeding 3.5oC and transient climate response values exceeding 1.8oC.
At the lower end of the sensitivity ranges reported by the IPCC AR5 are values of the climate sensitivity determined using an energy budget model approach that matches global surface temperatures with greenhouse gas concentrations and other forcings (such as solar variations and aerosol forcings) over the last century or so. I coauthored a paper recently published in Climate Dynamics that used this approach to determine climate sensitivity. Our calculations used the same forcing data given by the IPCC AR5, and we included a detailed accounting of the impact of uncertainties in the forcing data on our climate sensitivity estimates.
Our results show the best (median) estimate for equilibrium climate sensitivity is 1.64oC, with a likely (17–83% probability) range of 1.25–2.45oC. The median estimate for Transient Climate Response is 1.33oC with a likely range of 10.5-1.80oC. Most significantly, our new results support narrower likely ranges for climate sensitivity with far lower upper limits than reported by the IPCC AR5. Our upper limits lie below – for equilibrium climate sensitivity, substantially below – the average values of climate models used for warming projections. The true climate sensitivity may even be lower, since the energy budget model assumes that all climate change is forced, and does not account for the effects of decadal and century scale internal variability associated with long-term ocean oscillations.
These new climate sensitivity estimates adds to the growing evidence that climate models are running ‘too hot.’ At the heart of the recent scientific debate on climate change is the ‘pause’ or ‘hiatus’ in global warming – the period since 1998 during which global average surface temperatures have not increased. This observed warming hiatus contrasts with the expectation from the 2007 IPCC Fourth Assessment Report that warming would proceed at a rate of 0.2oC/per decade in the early decades of the 21st century. The warming hiatus combined with assessments that the climate model sensitivities are too high raises serious questions as to whether the climate model projections of 21st century have much utility for decision making.
The sensitivity of our climate to increasing concentrations of carbon dioxide is at the heart of the public debate on the appropriate policy response to increasing carbon dioxide in the atmosphere. Climate sensitivity and estimates of its uncertainty are key inputs into the economic models that drive cost-benefit analyses and estimates of the social cost of carbon.
Continuing to use the higher global climate model-derived values of climate sensitivity skews the cost-benefit analyses and estimates of the social cost of carbon. The implications of the lower values of climate sensitivity in our paper is that human caused warming near the end of the 21st century should be less than the 2oC ‘danger’ level for all but the most extreme emission scenario considered by the IPCC AR5. This delay in the warming – relative to climate model projections – relaxes the phase out period for greenhouse gas emissions, allowing more time to find ways to decarbonize the economy affordably and the flexibility to revise our policies as further information becomes available.
Vida Pós-Graduação
Achei a música ótima!
Vida Pós-Graduação
"Preciso dar aula,
a bolsa é uma esmola,
a faculdade é longe
e eu vou de busão.
Eu tô acordando já são cinco horas
e já tô atrasado pra uma reunião.
Quero terminar, quero descansar,
dormir oito horas por dia [EU RI!!!!]
Quero ver TV,
me alimentar bem
e ir para a academia"
Parabéns pela criatividade! O meu ouvido só doeu no fim... ;)
Vida Pós-Graduação
"Preciso dar aula,
a bolsa é uma esmola,
a faculdade é longe
e eu vou de busão.
Eu tô acordando já são cinco horas
e já tô atrasado pra uma reunião.
Quero terminar, quero descansar,
dormir oito horas por dia [EU RI!!!!]
Quero ver TV,
me alimentar bem
e ir para a academia"
Parabéns pela criatividade! O meu ouvido só doeu no fim... ;)
As melhores árvores de Natal
A maior do mundo é uma árvore digital na Times Square, em Nova York, acesa nesta sexta-feira, 19, com tecnologia de última geração
A árvore de Natal mais alta do mundo foi acesa pela primeira vez nesta quinta-feira, 19, na Times Square, em Nova York. Trata-se de uma árvore digital que utiliza tecnologia de última geração. Como ela, milhares de outras árvores natalinas no mundo inteiro ajudam a animar o espírito de confraternização que tanto favorece o comércio nesta época do ano. Confira as imagens das mais famosas árvores de Natal modelo 2014:
Assinar:
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