Junho: o mais quente da história

Publicado em 20/07/2016 por Felipe Poli Rodrigues

Dados da Nasa mostram que primeiro semestre teve temperatura 1,3 grau Celsius mais alta do que no fim do século 19, praticamente garantindo o recorde de 2016 como ano mais quente de todos.

mapaNasa

Publicado originalmente em 20/07/2016

Duas agências do governo americano divulgaram nesta terça-feira (19) dados sobre temperaturas globais em junho. Sem surpresa, ambas mostram que o mês passado foi o junho mais quente de todos os tempos desde o início dos registros, em 1880. Segundo a Noaa (Administração Nacional de Oceanos e Atmosfera), foi o 14o mês consecutivo a bater recordes absolutos de temperatura, o que praticamente garante o lugar de 2016 na história como o ano mais quente de todos os tempos.

De acordo com a Noaa, a temperatura da superfície terrestre e dos oceanos no mês foi 0,90oC superior à média para junho no século 20, ultrapassando 2015 – o recordista anterior – em 0,02oC. Na média do ano até aqui, a temperatura global foi 1,05oC mais alta que a média do século 20, ultrapassando o recorde de 2015 em 0,2oC. Segundo comunicado divulgado pela agência americana, a fila de meses consecutivos com recordes de temperatura é a maior em 137 anos de registro. O último mês com temperaturas abaixo da média do século 20 foi dezembro de 1984.

A Nasa mostrou a mesma tendência, mas usando uma “régua” diferente. A agência espacial americana calcula as chamadas “anomalias de temperatura” (ou seja, o quanto um determinado mês é mais quente ou mais frio do que a média histórica para esse mesmo mês) em relação ao período 1951-1980. Por essa conta, junho de 2016 foi 0,79oC mais quente que a média, superando junho de 2015 também em 0,02oC. Segundo a Nasa. Segundo a metodologia da Nasa, o último mês com temperaturas abaixo da média foi julho de 1985. Para a agência espacial, a temperatura do primeiro semestre foi 1,3oC mais alta do que a média do fim do século 19.

“Embora o El Niño no Pacífico tenha dado um impulso às temperaturas globais a partir de outubro, é a tendência subjacente [de aquecimento global] que está produzindo essas cifras recorde”, disse Gavin Schmidt, diretor do Centro Goddard de Estudos Espaciais, da Nasa.

Mais uma vez, eventos climáticos extremos campearam mundo afora. A América do Norte teve seu junho mais quente, e condições de temperatura extrema também predominaram na Amazônia, no Nordeste do Brasil e na África. O gelo marinho no Ártico teve a menor extensão registrada para aquele mês – 11,8% abaixo da média, devido ao calor extremo no semestre sobre a região polar.

“O recorde de temperaturas globais já dura mais de um ano, mas as altas temperaturas no Ártico têm sido ainda mais extremas”, afirmou Walt Meier, também da Nasa.

Tempestades atingiram a Europa e a Austrália, onde choveu mais do que o dobro da média em junho. A região centro-sul da América do Sul, porém, viu temperaturas 1oC mais baixas do que a média – resultado da onda de frio que atingiu o Sul e o Sudeste do Brasil, o Paraguai e parte da Bolívia naquele mês.

Fonte: Envolverde

 

 

O que o brasileiro pensa sobre meio ambiente

Publicado em 16/07/2016 por Felipe Poli Rodrigues

conservacaoambientalshutterstock_287860979-630x315

Postado Originalmente: 14/07/2016

Questões ambientais e de sustentabilidade estão na pauta do cotidiano. No entanto, é preciso saber o que as pessoas pensam sobre meio ambiente e como reagem a questões que estão cada vez mais presentes no dia a dia.

O instituto de pesquisa Market Analysisdedicado ao estudo de temas como responsabilidade social, sustentabilidade e consumo consciente elaborou uma pesquisa detalhada para saber qual a percepção dos desafios ambientais e como as pessoas reagem.

Tecnologias para ajudar a ter um estilo de vida sustentável e diminuir o impacto ambiental já são parte deste contexto, assim como a preocupação crescente das instituições sociais e governamentais nesta área de atuação. Mas o que pensa o brasileiro desde uma perspectiva individual sobre estas iniciativas? Existe consciência ambiental na sociedade?

A pesquisa “Entendendo o Contexto da Opinião Ambiental”, divulgada esta semana pelo Instituto Market Analysis mostra que temas como Poluição de rios, lagos e oceanos, Poluição do ar em geral, Escassez de água potável, As emissões de gases dos automóveis, Mudanças climáticas/aquecimento global e A diminuição dos recursos naturais são considerados de extrema gravidade por mais de 90% dos entrevistados. No entanto as reações em relação às soluções ainda são bastante díspares, com uma parte das pessoas considerando que a inovação tecnológica vai ajudar a superar essas questões, enquanto outra parte acredita que é necessária uma mudança de comportamento.

Outro dado interessante é sobre os atores que podem ajudar a resolver os problemas. A maior parte das pessoas não acredita que governos possam solucionar essas questões e colocam uma maior confiança em organizações sociais e empresas.

Leia aqui a íntegra da pesquisa: Entendendo o Contexto da Opinião Ambiental.

Fonte:Envolverde

Cutting carbon emissions isn’t enough. We need negative emissions.

Publicado em 13/07/2016 por Felipe Poli Rodrigues

negative-emissions

Publicado Originalmente: 13/07/2016

Humans will have to not only stop emitting greenhouse gases by 2085, but also develop technology that will result in negative emissions — the removal of 15 billion tons of carbon dioxide from the atmosphere each year by the end of the century — in order to prevent global warming from exceeding 2 degrees C (3.6 degrees F), according to a new study.

Human greenhouse gas emissions, including methane and carbon dioxide, have already warmed the globe more than 1 degree C (1.8 degrees F) compared to pre-industrial levels. The Paris Climate Agreement negotiated last year seeks to cap warming to below 2 degrees C, while at the same time pursuing an even more ambitious goal of limiting warming to 1.5 degrees C.

But according to a new National Center for Atmospheric Research study, just cutting emissions under the Paris agreement may not be enough to keep global warming from blasting past 2 degrees C, said Benjamin Sanderson, the study’s lead author.

Meeting the Paris agreement as written will require a long-term commitment to negative emissions in the last two decades of the century, he said.

Countries have agreed to cut total annual global greenhouse gas emissions from about 60 billion metric tons of carbon dioxide-equivalent today to about 54 billion tons in 2030. Without steeper emissions cuts sooner, about 15 billion tons of carbon dioxide will have to be removed from the atmosphere every year by the end of the century in order to keep within 2 degrees C of warming, he said.

Sabine Fuss, a negative emissions researcher at the Mercator Research Institute on Global Commons and Climate Change in Berlin, said the NCAR research confirms that individual countries’ emissions cuts pledges under the Paris agreement are insufficient to meet the pact’s global warming goals.

The study is in line with earlier research supporting negative emissions and its approach gives scientists a better understanding of when emissions cuts and carbon removal are necessary to keep global warming in check, she said.

Negative emissions aren’t a new idea. The Intergovernmental Panel on Climate Change included negative emissions in some of its climate stabilization scenarios in its Fifth Assessment Report in 2014. The IPCC warned that the feasibility of removing carbon from the atmosphere is highly uncertain, however, in part because the technology remains unproven and scientists haven’t assessed any risks carbon removal may pose.

Negative emissions technology isn’t being used anywhere in a significant way today, and the best options for carbon removal have major land and environmental impacts, Fuss said.

emissions-graph1

This graph shows the possible global carbon emissions trajectories that would have a two-in-three chance of keeping global warming from exceeding 2 degrees C (3.6 degrees F). The blue line represents the current emissions trajectory. The red line represents the path that society will be on if countries adhere to the Paris Agreement. The gray lines represent other possibilities, all of which require more stringent emissions cuts in the near term but fewer negative emissions later.

Scientists are studying many different ways of atmospheric carbon removal, Sanderson said. Chief among them is a method called “bioenergy, carbon capture, and storage,” or BECCS. It works like this: Trees and other plants, which absorb atmospheric carbon, are grown specifically for carbon removal, then they’re burned to generate electricity, and the emissions are captured and sequestered underground.

Other strategies involve planting large forests across the globe, directly capturing carbon dioxide from the atmosphere and altering soil management to increase the amount of carbon it can store.

“None of these have been demonstrated to be plausible on a large scale,” Sanderson said, adding that the billions of tons of carbon dioxide that would need to be removed from the atmosphere could come at “a phenomenal cost.”

Nobody knows for sure how successful or feasible any of those technologies will be in scrubbing the sky of carbon dioxide, but the NCAR study shows that the urgency of climate change may demand that scientists develop solutions by the time today’s children are adults in addition to slashing emissions as much as possible in the meantime.

“Negative emissions will not play a significant role in any emissions reductions which might occur over the next 15 years,” Sanderson said. “They will need to come from transitions to cleaner alternatives in the energy and transportation sectors.”

Fonte:Grist

Acordo de Paris tem adesão recorde

Publicado Originalmente: 22/04/2016

A implementação do Acordo de Paris contra as mudanças climáticas teve seu primeiro passo nesta sexta-feira (22), quando representantes de 171 países assinaram o documento na sede das Nações Unidas, em Nova York. Foi a maior adesão simultânea a um acordo internacional da história da ONU, superando de longe o recorde da Convenção para o Direito do Mar, de 1982, que teve 119 assinaturas. No mesmo dia, 15 países depositaram seus instrumentos de ratificação, mostrando forte apoio à transformação do acordo em ação acelerada contra as mudanças climáticas. Os três maiores emissores do mundo, EUA, China e União Europeia, anunciaram sua intenção de ratificar ainda este ano.

A cerimônia marcou o início de um novo capítulo nas negociações internacionais sobre o clima. Com a assinatura, os países mostraram que aceitam o acordo a nível nacional e se comprometeram a delinear seus calendários nacionais de ação para assegurar que o acordo venha a ter força de lei internacional, ajudando a transformar as promessas feitas na conferência do clima de Paris, no ano passado, em ação contra as mudanças climáticas.

“Estamos fazendo história aqui”, afirmou o secretário-geral da ONU, Ban Ki-moon, na abertura da cerimônia, ao comentar o número de assinaturas. “Estamos quebrando recordes nesta sala, e isso é uma boa notícia. Mas outros recordes estão sendo quebrados lá fora: o recorde de temperaturas, o recorde de perda de gelo e recorde de nível de carbono na atmosfera.” Segundo Ban, o mundo está numa “corrida contra o tempo” e os países devem transformar o acordo em lei doméstica o quanto antes.

No encerramento, o ator e militante ambiental Leonardo DiCaprio também ressaltou o senso de urgência, falando aos delegados: “Vocês sabem que a mudança climática está acontecendo mais rápido do que os cientistas mais pessimistas nos alertaram décadas atrás, e está se tornando um trem desgovernado trazendo consigo um desastre iminente para todas as coisas vivas”, disse. “Sim, nós obtivemos o Acordo de Paris (…) mas as evidências nos mostram que isso não basta. Nosso planeta não poderá ser salvo a menos que deixemos os combustíveis fósseis no subsolo, que é o lugar deles.”

A cerimônia desta sexta-feira em Nova York é um momento político crucial, por mostrar que o espírito de engajamento visto em Paris se mantém. A presença de vários chefes de Estado, como a presidente Dilma Rousseff e o premiê canadense Justin Trudeau, acrescentou peso ao evento. Mas ele não retira um grama sequer de dióxido de carbono da economia global ou da atmosfera. Ainda é necessário que pelo menos 55 países, que representem 55% das emissões mundiais, ratifiquem o Acordo de Paris – ou seja, transformem-no em lei – antes que ele entre em vigor, em 2020. E, igualmente importante, é preciso que os países revejam o quanto antes o nível de ambição de suas metas nacionals (as chamadas INDCs), já que o nível agregado de ambição das promessas de cada um ainda mantém o mundo numa trajetória de aquecimento de 2,7oC a 3,5oC neste século.

Para a assinatura, Ban havia demandado aos países que fizessem quatro coisas: atualizassem a ONU sobre como pretendem implantar seus planos de combate à mudança do clima; delineassem seus roteiros de aumento de ambição de forma a colocar o mundo na trajetória do objetivo de Paris de manter o aquecimento bem abaixo dos 2oC; indicassem o calendário de ratificação; e anunciassem mais esforços na ação até 2020.

Alguns países cumpriram parte da tarefa. O presidente da França, François Hollande, anunciou que a União Europeia, terceiro maior emissor do planeta, prepara a ratificação para este ano. Zhang Gaoli, vice-primeiro-ministro da China, prometeu que o maior emissor do planeta ratificaria o Acordo de Paris em setembro. E John Kerry, secretário de Estado dos EUA, anunciou que o maior emissor histórico e segundo maior emissor do mundo está “esperando se juntar ao acordo neste ano”.

Os EUA não devem ratificar o acordo, já que isso depende do Senado – que tem por tradição não ratificar tratados internacionais, menos ainda em clima, agenda contrária à do Partido Republicano. A adesão americana deve se dar por um ato do Poder Executivo, mas terá peso de lei.

Kerry, que assinou o acordo em nome do presidente Barack Obama com a neta Alex no colo, disse que Paris foi um ponto de virada, mas que a guerra do clima está longe de estar ganha. “Nada do que precisamos fazer está além das nossas capacidades tecnológicas. A única questão é se está além da nossa resolução coletiva”, disse.

Dilma

A presidente Dilma Rousseff fez um discurso de cerca de nove minutos, no qual assumiu o compromisso de assegurar a “pronta entrada em vigor” do acordo no Brasil.

Dilma, porém, não se comprometeu com um calendário de ratificação, não delineou como o Brasil pretende aumentar suas ações e limitou-se a cobrar mais compromissos dos países ricos e a reiterar as metas assumidas em setembro do ano passado, na INDC. “Realizar os compromissos que assumimos irá exigir a ação convergente de todos nós, de todos os nossos países e sociedades, rumo a uma vida e a uma economia menos dependentes de combustíveis fósseis”, afirmou a presidente.

“A presidente frustrou quem esperava uma demonstração de grande liderança do Brasil na ação contra a crise climática”, afirmou Carlos Rittl, secretário-executivo do OC. “Preferiu apenas reafirmar compromissos já anunciados, em vez de dizer como o país pretende aumentar sua ambição climática daqui para a frente. Falou da importância de seguirmos, todos, um caminho de desenvolvimento sustentável. Mas não deu nenhum sinal de que iremos mudar o modelo insustentável de desenvolvimento atual, que privilegia os combustíveis fósseis.”

Segundo Rittl, num país em profunda recessão, é fundamental  perceber que o que é bom para o clima é bom para a economia. “O governo brasileiro, porém, parece ainda ter medo de falar sobre acelerar a descarbonização. Felizmente a sociedade nacional está se mexendo muito mais rápido do que o poder público e trabalhando para tornar a ação climática agenda estratégica de desenvolvimento do país.”

FONTE: Observatório do Clima

You can wave goodbye to this global warming goal

Publicado Originalmente: 20/04/2016

Global leaders are meeting in New York this week to sign the Paris climate agreement. One of the expressed purposes of the document is to limit warming to “well below 2 degrees C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5 degrees C.”

A Climate Central analysis shows that the world will have to dramatically accelerate emissions reductions if it wants to meet that goal. The average global temperature change for the first three months of 2016 was 1.48 degrees C, essentially equaling the 1.5 degrees C warming threshold agreed to by COP 21 negotiators in Paris last December.

February exceeded the 1.5 degrees C target at 1.55 degrees C, marking the first time the global average temperature has surpassed the sobering milestone in any month. March followed suit checking in at 1.5 degrees C. January’s mark of 1.4 degrees C, put the global average temperature change from early industrial levels for the first three months of 2016 at 1.48 degrees C.

on the edge of 1.5 C

Climate Central scientists and statisticians made these calculations based on an average of global temperature data reported by NASA and the National Oceanic and Atmospheric Administration (NOAA). But rather than using the baselines those agencies employ, Climate Central compared 2016’s temperature anomalies to an 1881-1910 average temperature baseline, the earliest date for which global temperature data are considered reliable. NASA reports global temperature change in reference to a 1951-1980 climate baseline, and NOAA reports the anomaly in reference to a 20th century average temperature.

NASA’s data alone showed a February temperature anomaly of 1.63 degrees C above early industrial levels with March at 1.54 degrees C.

Calculating a baseline closer to the pre-industrial era provides a useful measure of global temperature for policymakers and the public to better track how successful the world’s efforts are in keeping global warming below agreed-upon thresholds.

A similar adjustment can be applied to some of the temperature change projections in the most recent IPCC report.

The IPCC AR5 Working Group 1 Report contains projections of future global surface temperature change according to several scenarios of future socio-economic development, most of which are presented using a baseline of 1986 to 2005. The IPCC chose this baseline in order to provide its readers a more immediate base of comparison, the climate of the present world, which people are familiar with. But these representations may suggest that the Paris goals are easier to reach than is true.

The IPCC’s presentation of these scenarios was not designed to inform the discussion about warming limits (e.g., 1.5 degrees C, 2 degrees C goals of the Paris COP21 agreements). But the Panel does provide a way to make its projections of future warming consistent with discussions about targets.

IPCC estimates, using the best and longest record available, show that the difference between the 1986-2005 global average temperature value used in most of the Panel’s projections, and pre-industrial global average temperature, is 0.61 degrees C (0.55-0.67). Neglecting 0.61 degrees C warming is not trivial, and makes a significant difference for the assessment of the goals established in Paris. In fact, 0.61 degrees C amounts to about half the warming already experienced thus far.

To capture this warming and display the IPCC warming time series relative to the pre-industrial period, Climate Central adjusted a well known IPCC projection (SPM7(a)) to reflect a 1880-1910 baseline. This adjustment has a significant effect on the dates at which the 1.5 and 2 degrees C thresholds are crossed, moving them up by about 15-20 years.

If current emissions trends continue (RCP8.5) we could cross the 1.5 degrees C threshold in 10 to 15 years, somewhere between the years 2025-2030, compared to 2045-2050 when a 1985-2005 baseline is used.

The dramatic global hot streak that kicked off 2016 doesn’t mean the world has already failed to meet the goals in the Paris agreement. Three months do not make a year, and it is unlikely that 2016 will exceed the 1881-1910 climate-normal by 1.5 degrees C. This year is also in the wake of a strong El Niño, when higher-than-average temperatures would be expected.

And of course, exceeding the 1.5 degrees C threshold for even an entire year would not mean that global temperatures had in fact risen to that point, never (at least within our lifetime) to drop back below it as it’s too short of a time frame to make that determination.

But the hot start for 2016 is a notable symbolic milestone. The day the world first crossed the 400 parts per million (ppm) threshold for atmospheric carbon dioxide heralded a future of ever increasing carbon dioxide. So too, do the first three months of 2016 send a clear signal of where our world is headed and how fast we are headed there if drastic actions to reduce carbon emissions are not taken immediately.

Background

On Dec. 12, 2015, the 21st Conference of the Parties to the U.N. Framework Convention on Climate Change approved the Paris Agreement committing 195 nations of the world to “holding the increase in the global average temperature to well below 2 degrees C above preindustrial levels and pursuing efforts to limit the temperature increase to 1.5 degrees C.” The pact commits the world to adopt nationally determined policies to limit greenhouse gas emissions in accord with those goals.

The 2 degrees C goal represents a temperature increase from a pre-industrial baseline that scientists believe will maintain the relatively stable climate conditions that humans and other species have adapted to over the previous 12,000 years. It will also minimize some of the worst impacts of climate change: drought, heat waves, heavy rain and flooding, and sea-level rise. Limiting the global surface temperature increase to 1.5 degrees C would lessen these impacts even further.

1.5 and 2 degrees C are not hard and fast limits beyond which disaster is imminent, but they are now the milestones by which the world measures all progress toward slowing global warming. And yet it is surprisingly difficult to find objective measures that answer the question, where are we today on the path toward meeting the 1.5 or 2 degrees C goals?

Every month NOAA and NASA update their global surface temperature change analysis, using data from the Global Historical Climate Network, and methods validated in the peer-reviewed literature (Hansen et al. 2010; NCDC). The monthly updates are posted on their websites, and made available to the public along with the underlying data and assumptions that go into their calculations.

These calculations are enormously useful for understanding the magnitude and pace of global warming. In fact, they are the bedrock measurements validating the fact that our planet is warming at all.

But none present their results in comparison to a pre-industrial climate normal.

Methods and Results

The NASA and NOAA monthly updates are presented as anomalies, or as the deviation from a baseline climate normal, calculated as an average of a 30-year reference period, or the 20th century average; they do not represent an absolute temperature increase from a specific date. NASA presents their results in reference to a 1951 to 1980 average temperature, NOAA in reference to a 20th century average temperature.

The NASA results, calculated by Goddard Institute for Space Studies, are published monthly on the NASA/GISS website (GISTEMP). NOAA methods and monthly updates are published via the National Centers for Environmental Informationhere.

Climate Central used data from NASA and NOAA to create an 1881 to 1910 climate normal for the months of January, February, and March. We then compared the reported monthly 2016 anomaly for each of these months to this “early-industrial” baseline reference period.  These anomalies were then averaged to produce a mean monthly NASA/NOAA anomaly for each month. The results are presented below.

The NASA anomaly is considerably higher than the anomaly reported by NOAA. This reflects the fact the NASA’s calculations are tuned to account for temperature changes at the poles, where there are far fewer monitoring stations. NOAA relies only on historical station data and makes no adjustment to account for sparse records at the poles, where warming has been more rapid relative to non-polar regions.

global temp anomalies

 

FONTE: Grist

Mudanças climáticas podem gerar rombo financeiro trilionário

Postado Originalmente: 04/04/2016

As mudanças climáticas podem gerar um rombo de US$ 2,5 trilhões no valor dos ativos financeiros em todo o mundo, de acordo com a primeira grande estimativa de modelagem econômica já realizada sobre o assunto.

Essas perdas valem para o cenário da temperatura média da superfície global alcançar 2,5° C acima do nível pré-industrial, até 2100.

O estudo é assinado por pesquisadores do Instituto de Pesquisa Grantham sobre Mudanças do Clima e do Ambiente na London School of Economics and Political Science and Vivid Economics e foi publicado hoje (4) na revista “Nature Climate Change”.

Esse número, no entanto, pode ser maior. Nos piores cenários, muitas vezes usados pelos reguladores para verificar a saúde financeira das empresas e das economias, as perdas poderiam subir para US$ 24 trilhões, ou 17% de todos os ativos do mundo, e arruinar a economia global.

Os autores ressaltam que essas somas são maiores do que os US$ 5 trilhões estimados para a capitalização total do mercado de ações das empresas de combustíveis fósseis atualmente.

As perdas seriam causadas pela destruição direta de ativos devido ao aumento de eventos climáticos extremos e também por uma redução nos lucros para os afetados por altas temperaturas, secas, além de instabilidade geopolítica, entre outros impactos da mudança climática.

Segundo o pesquisador Simon Dietz, “os resultados podem surpreender os investidores, mas não será surpresa para muitos economistas que se debruçam sobre os efeitos das mudanças climáticas”.

Se forem tomadas medidas para combater as mudanças climáticas, o estudo descobriu que seria possível reduzir as perdas financeiras globais.

“Ao longo dos últimos anos, os modelos econômicos vêm gerando estimativas cada vez mais pessimistas sobre os impactos do aquecimento global sobre o crescimento econômico futuro. Mas também descobrimos que cortar os gases de efeito estufa para limitar o aquecimento global a não mais do que 2°C reduz substancialmente o valor em risco frente ao clima.”

Num cenário mais positivo, limitar o aquecimento a 2°C até 2100 reduziria significativamente as perdas. Nesse caso, o valor médio dos ativos financeiros globais em risco seria de US$ 1,7 trilhão, com 1% chance de que US$ 13,2 trilhões estejam em risco.

Preocupações sobre aquecimento global já encabeçam as discussões de economistas. Em janeiro, o Fórum Econômico Mundial disse que o fracasso da adaptação e mitigação das mudanças climáticas é a maior ameaça potencial para a economia global em 2016.

FONTE: Planeta Sustentável 

Is it possible to reduce CO2 emissions and grow the global economy?

Publicado Originalmente: 14/04/2016

The statistic is startling. In the past two years, the global economy has grown by 6.5 percent, but carbon dioxide emissions from energy generation and transport have not grown at all, the International Energy Agency (IEA) reported last month. CO2 emissions in Europe, the United States, and — most stunningly — China have been falling. What is going on?

These numbers raise a key question of huge importance if nations are to avoid the worst effects of climate change: Is the world on a path toward “decoupling” economic activity from carbon dioxide emissions?

Put another way: Is the idea of a future of “green growth,” with prosperity rising and emissions falling, real? Or as some fear, is it a dangerous myth?

When the United Nations holds an official signing ceremony for the Paris climate agreement on April 22, the hope is this high-profile event will ensure political momentum for meeting the Paris pledge to halt global warming at “well below” two degrees Celsius. But even climate scientists elated by the Paris agreement agree that, even with political will, the task will be extremely tough. Many are unsure whether to be optimists, keen to show the job can be done, or pessimists, determined to ensure nobody thinks it will be easy.

In its analysis last month, the IEA, a body linked with the Organization for Economic Co-operation and Development (OECD), reported that global CO2 emissions from energy-related activities have not risen since 2013, staying at 32.1 billion tons even as the global economy grew.

This surprising “decoupling” of emissions from economic activity was led by the two largest emitters, China and the U.S., which both registered declines in emissions of about 1.5 percent.

The IEA finding followed a similar conclusion about global emissions from an international team of climate scientists, headed by Corinne le Quere of the University of East Anglia in England, reported during the Paris climate conference last December.

A good part of the decoupling, both studies agree, is attributable to China. Its turnaround has been “quite remarkable,” says Fergus Green, an analyst of China’s energy policy at the London School of Economics. The country’s coal use grew annually by more than 8 percent between 2000 and 2013, and that growth was the biggest single cause of rising global CO2 emissions. As recently as 2011, China got 80 percent of its electricity from coal.

But growing concern about killer smogs has triggered new controls that mean many coal-burning power plants in China have now been mothballed. Coal burning fell by 3 percent in 2015, by which time the percentage of China’s electricity produced by coal had fallen to 70 percent, according to the IEA.

Chinese emissions from oil and gas burning continue to grow, Green says. But that is more than counterbalanced by a combination of declining use of coal and reductions in energy demand from structural changes in the Chinese economy, with energy-guzzling heavy industries like cement and steel production both now declining.

Per head of population, Chinese emissions exceed those of Europe, even though average income is less than a half that of citizens of the European Union. But China seems set on the road to climate redemption. In Paris, Beijing pledged to peak emissions by 2030. In fact, it may already have done so, says Green. And even if not, he foresees only small increases from now on.

China is following a road already taken by more economically developed nations. The carbon intensity of high-income OECD countries has more than halved since 1970, meaning half as much CO2 is now emitted for every dollar of GDP.

Lately, things have gone further. U.S. emissions have been falling for more than half a decade now, as coal burning is replaced by fracked natural gas and wind power. The United States has become 28 percent richer, but 6 percent cleaner since 2000, says Nate Aden of the World Resources Institute, who reported that, since 2000, 21 countries — all in Europe, except the U.S. and Uzbekistan — have reduced their carbon emissions while growing GDP.

Britain, for instance, grew its economy by 27 percent while cutting emissions by 20 percent between 2000 and 2014.

Part of this national decoupling is a result of advanced economies offshoring heavy industry to places like China, says Aden, with most of the “decouplers” having reduced the industrial share of their economic activity. But this is a minor element, he believes. These 21 nations show an average emissions reduction of 15 percent, but cuts in the industrial share of GDP are just 3 percent.

That said, clearly not all countries are decoupling. Emissions continue to rise in much of Asia and the Middle East. From Turkey to India, enthusiasm for coal remains strong. India has plans to double its already large coal production, which the Delhi government justifies by pointing out that its per-capita emissions remain only one-tenth of those of the U.S. But optimists note that, despite the bluster, India also has big plans for expanding solar energy production.

It is far from clear, says the University of East Anglia’s le Quere, that the world has yet reached peak emissions of CO2 from energy sources — still less that this translates into a peak in greenhouse gas emissions overall. But with the three largest emitters — China, the U.S., and the European Union — all showing evidence of decoupling, the signs are suddenly rather encouraging.

The first hint that decoupling was under way came four years ago, when a report from the Netherlands Environmental Assessment Agency and the European Commission’s Joint Research Center (JRC) found that in 2012,CO2 emissions rose just 1.1 percent globally, while GDP rose 3.5 percent. Greet Janssens-Maenhout of the JRC says now: “There has been continuous and increasing decoupling over the past four years.”

There is no modern precedent. Global CO2 emissions growth briefly faltered in the early 1980s, in 1992, and again in 2009; but in each case this was due to a decline in economic activity.

The biggest cause of decoupling is the dramatic growth of renewable energy. Last year, more than twice as much money was put into new capacity for renewables such as solar and wind power than into new power stations burning fossil fuels, according to a new analysis by the Frankfurt School of Finance and Management. For the first time, the majority of this investment was in developing countries, with China responsible for 36 percent of the total.

The reason has as much to do with price as climate policies. The cost of photovoltaic equipment, much of it manufactured in China, has fallen by 80 percent in the past decade. As a result, auctions for solar power in Texashave recently seen prices as low as 4 cents per kilowatt hour, which is below the price of most coal-generated energy.

Renewables still only deliver about 10 percent of the total electricity generated worldwide. Even so, Ulf Moslener, a coauthor of the Frankfurt report, said recent investment in green energy has cut annual CO2 emissions from all energy sources, including transport, by about 1.5 billion tons, or 5 percent, from where they would otherwise be.

The growth of renewables is being accompanied by a sharp decline in coal burning, not only in China, but in the U.S. and elsewhere. Canadian climate blogger Kyla Mandel recently noted that a quarter of European Union countries no longer burn any coal for power generation.

This process is being amplified by a flight of capital, as investors fear that expensive coal mines and coal-burning power plants may become “stranded assets,” with no markets, as renewables ramp up and limits on CO2 emissions begin to bite. The coal industry has been hit hard, with the largest U.S. coal company, Peabody Energy, filing for Chapter 11 bankruptcy protection just this week.

This concern is likely to spread to other fossil fuels, says British energy analyst and former Greenpeace science director Jeremy Leggett. Current low oil prices may encourage oil burning and could postpone the market penetration of, for instance, electric cars. But low prices also discourage investment in new oil fields. As Leggett put it in a recent blog: “Most fossil fuel companies face a future in which they might not have the capital to expand even if they still want to.”

But there are countervailing trends. The IEA’s emissions audit does not cover all CO2 emissions. Deforestation for the past half century has been a major source of greenhouse gas emissions, although that too now appears to be declining. More worrying — because they are still increasing fast but were left out of the Paris agreement — are emissions from international aviation and shipping.

Expansion plans for the aviation industry could lead to emissions from this source tripling by 2040, says Annie Petsonk of the Environmental Defense Fund. Once these are taken into account, “the decoupling claimed for many nations disappears altogether,” says Kevin Anderson of the University of Manchester in England.

The aviation industry may reach agreement later this year on plans to offset its emissions by investing in United Nations schemes for forest conservation.

But some environmentalists are concerned that the industry will simply be funding projects already promised by governments as part of their plans to meet their Paris pledges. If so, there will be no additional benefit to the planet.

There are growing concerns too about trends for some other greenhouse gases — in particular, the second most-important man-made planet warmer, methane, the main constituent of natural gas. When burned, natural gas produces energy with fewer CO2 emissions than coal. But if distribution systems leak significant amounts of gas, the warming effect of that methane could negate the benefit of switching off coal.

“Methane numbers may undermine the basic thesis [of decoupling],” says climate activist Bill McKibben, who recently wrote in The Nation that U.S. emissions of methane — “CO2’s nasty little brother” — have increased by more than 30 percent. In the article, McKibben pinpointed leakage from fracking as the likely cause.

This is a damaging failure of regulation, but at least it is fixable, at relatively low cost, according to studies by the United Nations Environment Programme. And while methane is a potent greenhouse gas, its lifetime in the atmosphere is roughly a decade, so we won’t be living with the consequences for nearly as long as those from CO2 emissions.

Even if global emissions of CO2 and other greenhouse gases can be curbed, however, this won’t fix climate change, say critics of the decoupling narrative. The big problem is that warming is driven not by annual emissions but by the accumulation of greenhouse gases in the atmosphere. And while methane may disappear relatively quickly, CO2 hangs around for centuries.

Last year, CO2 concentrations in the atmosphere exceeded 400 parts per million (ppm) for the first time. According to the U.N.’s Intergovernmental Panel on Climate Change, keeping global warming below two degrees probably requires keeping this figure below about 450 ppm. That means emitting in total no more than about 800 billion tons of CO2 from all sources — or less than 20 years worth at current rates. In practice, emissions have to be brought down to zero by mid-century.

“Set against the small and rapidly dwindling carbon [emissions] budgets associated with the Paris Agreement… the tentative signs of decoupling are of little relevance,” says Anderson, of Manchester University, an avowed pessimist. “The concept of green growth is very misleading.”

Others are more optimistic. Even if decoupling cannot limit warming to two degrees, it could deliver three or four degrees, after which the world might find ways to draw down CO2 from the atmosphere. But all agree the bottom line is that, as le Quere puts it, “we need to bring emissions down to zero. The faster we decrease the emissions, the less risk we take.”

Decoupling is real, but it is just the start.

FONTE: The Guardian