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Público, 01.04.2012
Jorge Talixa

"Em alguns sítios não temos outra solução a médio prazo que não seja deslocar populações", admite o secretário de Estado do Ambiente e do Ordenamento do Território, referindo-se ao crescente problema da erosão costeira em várias zonas do país e à progressiva elevação do nível do mar motivada pelas alterações climáticas.

Pedro Afonso de Paulo explica que Portugal não tem dinheiro para fazer paredes de betão semelhantes às que foram feitas na Holanda para funcionarem como diques e protegerem as populações da invasão da água do mar. Nesta altura, cerca de 30 por cento da costa portuguesa está sujeita a "muito forte erosão", acrescenta.

Por esta razão, o governante defende que será preciso tomar medidas para "proibir terminantemente a construção" em muitas áreas costeiras. "Dificilmente teremos meios e técnicas" que permitam suster este avanço das águas originado pelas alterações climáticas, justifica.

Pedro Afonso de Paulo participou, quinta-feira à noite, num colóquio sobre ambiente e ordenamento do território organizado pela comissão concelhia de Vila Franca de Xira do PSD. Em resposta a um dos participantes, previu que Portugal vai cumprir sem grandes dificuldades as metas de redução das emissões poluentes estabelecidas no Protocolo de Quioto.

"Infelizmente vamos cumprir as metas sem esforço", observou, frisando que a "desindustrialização" vivida pelo País durante muito tempo e a mais recente crise económica fizeram com que as emissões tenham baixado bastante.

"Temos menos indústria e, com a crise económica, não só as empresas emitem menos como as pessoas utilizam menos os carros", salientou, vincando, todavia, que cerca de 80 por cento das nossas emissões de CO2, ao contrário do que se pensa, têm origem na energia consumida nas casas dos portugueses e nos carros em circulação e não estão relacionadas com as fábricas e com a actividade económica.

"Acreditamos numa indústria que pode estar presente e não ser muito poluente. Infelizmente não somos um país muito industrializado, não produzimos tanto quanto poderíamos produzir", lamentou. "As estimativas todas dizem que vamos cumprir as metas de Quioto, o que também é importante", acrescentou o governante.

Pedro Afonso de Paulo disse, ainda, que o Governo apresentará em Abril um plano para o uso eficiente da água e um roteiro do baixo carbono. Estão a decorrer os processos de revisão da Lei de Bases do Ordenamento do Território e do Solo e do regime da Reserva Ecológica Nacional. Mas, também em resposta a alguns dos participantes no colóquio, o governante considerou muito difícil e oneroso aprofundar as políticas de reutilização de águas tratadas, porque exigiriam redes próprias, separadas, para o transporte destas águas para os meios urbanos, o que implicaria investimentos nesta altura incomportáveis.

Pedro Aguiar Pinto, professor do Instituto Superior de Agronomia, defendeu que as variações do clima em Portugal têm séculos e que, em média, até chove um pouco mais por ano em Lisboa do que em Londres. "Portugal tem uma preocupação, que é a grandíssima variabilidade do seu clima. Mas não devemos ter uma visão catastrófica", argumentou, considerando depois que há que desdramatizar esta questão. "Desdramatizar não é ignorar o risco. Mas é preciso não dramatizar e a agricultura tem uma grande capacidade de adaptação a novas situações", concluiu.

 

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Público, 19.03.2012
Nicolau Ferreira


De acordo com uma nova avaliação da evolução das temperaturas da Terra, o ano de 2010 passa a ser o mais quente desde 1850, em vez de 1998. Esta actualização, feita pelo HadCRUT, um dos principais registos de temperatura global, do Reino Unido, contou com novos dados de temperatura do Árctico. Os resultados foram publicados na revista Journal of Geophysical Research e mostram que esta actualização não altera o aumento médio de temperaturas desde 1900, de 0,75 graus.

A ciência do clima e a teoria largamente defendida de que a Terra está a registar um aumento de temperatura que não se explica por oscilações naturais, mas sim pela mão humana, está também baseada no registo das temperaturas do ar nos continentes e dos oceanos, ao longo de mais de um século.

Os dados da HadCRUT incluem informação das temperaturas nos continentes compiladas pela Unidade de Investigação Climática (CRU, sigla em inglês) da Universidade de East Anglia, em Norfolk, no Reino Unido e os registos de temperaturas da superfície dos oceanos, compilados pelo Centro de Hadley do Instituto de Meteorologia do Reino Unido. “O novo estudo reúne as nossas bases de dados mais recentes e mais completas das observações da temperatura da terra e do mar, em conjunto com novos avanços na compreensão de como se faziam as medições no mar”, disse Colin Morice, cientistas do Instituto Meteorológico do Reino Unido, citado pela AP. O resumo do artigo está disponível online (em inglês): clique aqui.

A primeira rede de estações meteorológicas data de 1653, no Norte de Itália, mas só a meio do século XIX é que o número de estações e a sua distribuição passou a ser suficientemente generalizada para ter validade científica.

Desde essa altura que os métodos têm vindo a ser optimizados e normalizados. Os cientistas tiveram agora em conta, por exemplo, o enviesamento nos registos de temperatura da superfície do oceano, quando era medida em baldes com água tirada do mar, em que havia uma descida de temperatura em relação à do oceano.

No novo artigo foram incluídas as observações de 400 estações meteorológicas no Árctico, na Rússia e no Canadá. Uma das regiões mais afectadas pelo aumento de temperatura. “A HadCRUT é sustentada por observações e tornou-se claro que [o modelo] poderia não estar a captar na sua totalidade as mudanças no Árctico, devido a haver tão pouca informação nesta área”, disse Phil Jones, director do CRU e primeiro autor do artigo, citado pela BBC News. Os resultados também utilizaram registos novos vindo da África e da Austrália.

“A actualização resultou em algumas mudanças em anos individuais, mas não mudou o sinal geral do aquecimento de cerca de 0,75 graus desde 1900”, disse Morice.

Mas o ano mais quente de todos, 1998, caiu para terceiro lugar, segundo a nova actualização, sendo substituído por 2010 e o ano de 2005 ficou em segundo lugar. Os dez anos mais quentes ocorreram todos nos últimos 14 anos. Outra conclusão, é que o aumento de temperatura não é homogéneo. “O Hemisfério Norte e o Hemisfério Sul aqueceram em 1,12 graus e 0,84º ao longo do período entre 1901 e 2010”, lê-se no resumo do artigo. Só desde 2001, o Norte aqueceu 0,1 graus.

No início deste ano, a NASA divulgou um relatório que previa um maior aquecimento da Terra nos próximos anos. De acordo com este trabalho da agência espacial norte-americana, o ano de 2011 acabou por ser o nono mais quente desde 1880. No ano passado, as temperaturas médias à superfície foram 0,51ºC mais altas do que os valores médios do período base 1951-1980.

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Reuters (www.reuters.com) Fri, Jul 8 2011

By Charlie Dunmore

BRUSSELS (Reuters) - Europe's biodiesel industry could be wiped out by EU plans to tackle the unwanted side effects of biofuel production, after studies showed few climate benefits, four papers obtained by Reuters show.

Europe's world-leading $13 billion biodiesel industry, which has boomed in the wake of a decision by Brussels policymakers in 2003 to promote it, is now on the verge of being legislated out of existence after the studies revealed biodiesel's indirect impact cancels out most of its benefits.

"This study would pave the way for the demise of the European biodiesel sector," Philippe Tillous-Borde, chief of French oilseed giant Sofiproteol, which owns Europe's largest biodiesel producer, told Reuters.

The EU has been arguing for two years over the extent of indirect damage to the environment caused by it setting a target of increasing biofuel use to 10 percent of all road fuels by 2020, from less than three percent today.

Its own analysis shows the target may lead to an indirect one-off release of around 1,000 megatonnes of carbon dioxide -- more than twice the annual emissions of Germany.

The emerging picture that the EU has got its policy wrong has proved unpalatable, and the European Commission has refused a Reuters freedom of information request for the latest studies, arguing the public interest of disclosure is insufficient.

However, those documents have now been leaked.

"This would have significant implications for the existing EU biodiesel industry," said one of the leaked reports seen by Reuters, an impact assessment prepared by the Commission.

"The viability of existing investments could be affected in the long run, as the availability of conventional biodiesel feedstocks would be extremely reduced," it said.

The findings could have a major impact on the direction of investments by major oil companies such as BP and Royal Dutch Shell in low-carbon energy sources, and give a boost to firms involved in the development of next-generation biofuels from non-crop sources, such as Danish enzymes producer Novozymes and Spain's Abengoa.

In a second report, global biofuel experts warned that increased biofuel production driven by the EU's green energy targets will squeeze food supplies and increase global hunger.

"Any decline in consumption can have a severe impact for households that are already malnourished," said the report from a Commission workshop of international biofuel experts last November.

THE "ILUC" DEBATE

Biofuels were once seen as a silver bullet for curbing transport emissions, based on a theory that they only emit as much carbon as they absorbed during growth.

But that has been undermined by a new concept known as "indirect land-use change" (ILUC), which scientists are still struggling to accurately quantify.

In essence, it means that if you take a field of grain and switch the crop to biofuel, somebody, somewhere, will go hungry unless those missing tonnes of grain are grown elsewhere.

The crops to make up the shortfall could come from anywhere, and recent research shows the majority of new farmland, possibly as much as 80 percent, is created by cutting down forests.

Burning forests to clear that land can pump climate-warming emissions into the atmosphere, enough in theory to cancel out any of the climate benefits the biofuels were meant to bring.

"The experts unanimously agreed that, even when uncertainties are high, there is strong evidence that the ILUC effect is significant," said the report from the Commission's November workshop.

"The land use change effects make nearly half of the expected gains of shifting from fossil fuels to renewable biofuels disappear," said a third report by the International Food Policy Research Institute (IFPRI) for the EU.

Biodiesel from Asian palm oil, South American soy beans, and EU rapeseed all had a bigger overall climate impact than conventional diesel, said a fourth leaked document.

"These reports clearly show scientists are convinced that current EU biofuels policy will indirectly cause significant environmental damage," said Nusa Urbancic at green transport campaign group T&E.

"The EU must stop brushing the problem under the carpet."

But many in the biodiesel industry -- which accounts for around 80 percent of all biofuels -- argue the science is still too uncertain to legislate.

"It would be totally contradictory to act on the basis of results produced by a model that relies on false, poorly researched hypotheses," said Sofiproteol's Tillous-Borde.

Yet, scientists are starting to agree on a clear sustainability ranking, after four in-depth EU studies in 2010 and three more in 2011, with bioethanol seen as a better option due to higher energy content in the plants used to produce it.

"Ethanol feedstocks have a lower land use change effect than the biodiesel feedstocks. For ethanol, sugar beet has the lowest land use emission coefficients," said the IFPRI report.

The Commission's impact analysis predicts EU demand for biodiesel will collapse if their indirect impacts are taken into account in EU legislation. But at the same time it sees a sharp rise in demand for bioethanol from cereal crops and sugarcane, as well as advanced biodiesel produced from algae.

"Ethanol production capacity would need to be increased significantly to make up for the increased demand," it said.

The report said this shift in demand would be reflected in commodity markets, pushing down vegetable oil prices and to a lesser extent increasing the cost of sugar and grains.

(Additional reporting by Pete Harrison; editing by Keiron Henderson)

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Climate models go cold

por papinto, em 20.05.11

Climate models go cold

Financial Post  Apr 7, 2011 – 8:46 PM ET | Last Updated: Apr 7, 2011 8:57 PM ET

 

Carbon warming too minor to be worth worrying about

By David Evans

The debate about global warming has reached ridiculous proportions and is full of micro-thin half-truths and misunderstandings. I am a scientist who was on the carbon gravy train, understands the evidence, was once an alarmist, but am now a skeptic. Watching this issue unfold has been amusing but, lately, worrying. This issue is tearing society apart, making fools out of our politicians.

Let’s set a few things straight.

The whole idea that carbon dioxide is the main cause of the recent global warming is based on a guess that was proved false by empirical evidence during the 1990s. But the gravy train was too big, with too many jobs, industries, trading profits, political careers, and the possibility of world government and total control riding on the outcome.So rather than admit they were wrong, the governments, and their tame climate scientists, now outrageously maintain the fiction that carbon dioxide is a dangerous pollutant.

Let’s be perfectly clear. Carbon dioxide is a greenhouse gas, and other things being equal, the more carbon dioxide in the air, the warmer the planet. Every bit of carbon dioxide that we emit warms the planet. But the issue is not whether carbon dioxide warms the planet, but how much.

Most scientists, on both sides, also agree on how much a given increase in the level of carbon dioxide raises the planet’s temperature, if just the extra carbon dioxide is considered. These calculations come from laboratory experiments; the basic physics have been well known for a century.

The disagreement comes about what happens next.

The planet reacts to that extra carbon dioxide, which changes everything. Most critically, the extra warmth causes more water to evaporate from the oceans. But does the water hang around and increase the height of moist air in the atmosphere, or does it simply create more clouds and rain? Back in 1980, when the carbon dioxide theory started, no one knew. The alarmists guessed that it would increase the height of moist air around the planet, which would warm the planet even further, because the moist air is also a greenhouse gas.

This is the core idea of every official climate model: For each bit of warming due to carbon dioxide, they claim it ends up causing three bits of warming due to the extra moist air. The climate models amplify the carbon dioxide warming by a factor of three — so two-thirds of their projected warming is due to extra moist air (and other factors); only one-third is due to extra carbon dioxide.

That’s the core of the issue. All the disagreements and misunderstandings spring from this. The alarmist case is based on this guess about moisture in the atmosphere, and there is simply no evidence for the amplification that is at the core of their alarmism.

Weather balloons had been measuring the atmosphere since the 1960s, many thousands of them every year. The climate models all predict that as the planet warms, a hot spot of moist air will develop over the tropics about 10 kilometres up, as the layer of moist air expands upwards into the cool dry air above. During the warming of the late 1970s, ’80s and ’90s, the weather balloons found no hot spot. None at all. Not even a small one. This evidence proves that the climate models are fundamentally flawed, that they greatly overestimate the temperature increases due to carbon dioxide.

This evidence first became clear around the mid-1990s.

At this point, official “climate science” stopped being a science. In science, empirical evidence always trumps theory, no matter how much you are in love with the theory. If theory and evidence disagree, real scientists scrap the theory. But official climate science ignored the crucial weather balloon evidence, and other subsequent evidence that backs it up, and instead clung to their carbon dioxide theory — that just happens to keep them in well-paying jobs with lavish research grants, and gives great political power to their government masters.

There are now several independent pieces of evidence showing that the earth responds to the warming due to extra carbon dioxide by dampening the warming. Every long-lived natural system behaves this way, counteracting any disturbance. Otherwise the system would be unstable. The climate system is no exception, and now we can prove it.

But the alarmists say the exact opposite, that the climate system amplifies any warming due to extra carbon dioxide, and is potentially unstable. It is no surprise that their predictions of planetary temperature made in 1988 to the U.S. Congress, and again in 1990, 1995, and 2001, have all proved much higher than reality.

They keep lowering the temperature increases they expect, from 0.30C per decade in 1990, to 0.20C per decade in 2001, and now 0.15C per decade — yet they have the gall to tell us “it’s worse than expected.” These people are not scientists. They overestimate the temperature increases due to carbon dioxide, selectively deny evidence, and now they conceal the truth.

One way they conceal is in the way they measure temperature.

The official thermometers are often located in the warm exhaust of air conditioning outlets, over hot tarmac at airports where they get blasts of hot air from jet engines, at waste-water plants where they get warmth from decomposing sewage, or in hot cities choked with cars and buildings. Global warming is measured in 10ths of a degree, so any extra heating nudge is important. In the United States, nearly 90% of official thermometers surveyed by volunteers violate official siting requirements that they not be too close to an artificial heating source.

Global temperature is also measured by satellites, which measure nearly the whole planet 24/7 without bias. The satellites say the hottest recent year was 1998, and that since 2001 the global temperature has levelled off. Why does official science track only the surface thermometer results and not mention the satellite results?

The Earth has been in a warming trend since the depth of the Little Ice Age around 1680. Human emissions of carbon dioxide were negligible before 1850 and have nearly all come after the Second World War, so human carbon dioxide cannot possibly have caused the trend. Within the trend, the Pacific Decadal Oscillation causes alternating global warming and cooling for 25 to 30 years at a go in each direction. We have just finished a warming phase, so expect mild global cooling for the next two decades.

We are now at an extraordinary juncture. Official climate science, which is funded and directed entirely by government, promotes a theory that is based on a guess about moist air that is now a known falsehood. Governments gleefully accept their advice, because the only ways to curb emissions are to impose taxes and extend government control over all energy use. And to curb emissions on a world scale might even lead to world government — how exciting for the political class!

Even if we stopped emitting all carbon dioxide tomorrow, completely shut up shop and went back to the Stone Age, according to the official government climate models it would be cooler in 2050 by about 0.015 degrees. But their models exaggerate 10-fold — in fact our sacrifices would make the planet in 2050 a mere 0.0015 degrees cooler!

Finally, to those who still believe the planet is in danger from our carbon dioxide emissions: Sorry, but you’ve been had. Yes, carbon dioxide is a cause of global warming, but it’s so minor it’s not worth doing much about.

Financial Post
David Evans consulted full-time for the Australian Greenhouse Office (now the Department of Climate Change) from 1999 to 2005, and part-time 2008 to 2010, modelling Australia’s carbon in plants, debris, mulch, soils, and forestry and agricultural products. He is a mathematician and engineer, with six university degrees, including a PhD from Stanford University in electrical engineering. The comments above were made to the Anti-Carbon-Tax Rally in Perth, Australia, on March 23.

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Alteracoes_climaticas_PNAC

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Alterações climáticas e agricultura

por papinto, em 25.03.11
Alteracoes_climaticas_agriculturaGreenISA

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Resilience

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Alteracoes_climaticas

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