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 http://www.sciencedaily.com/releases/2011/02/110216124233.htm

 

ScienceDaily (Feb. 16, 2011) — A new study from the University of Illinois concludes that very high yield biomass would be needed in order to meet the ambitious goal of replacing 30 percent of petroleum consumption in the U.S. with biofuels by 2030.

A team of researchers led by Madhu Khanna, a professor of agricultural and consumer economics at Illinois, shows that between 600 and 900 million metric tons of biomass could be produced in 2030 at a price of $140 per metric ton (in 2007 dollars) while still meeting demand for food with current assumptions about yields, production costs and land availability.

The paper, published in the American Journal of Agricultural Economics, is the first to study the technical potential and costs associated with producing a billion tons of biomass from different agricultural feedstocks -- including corn stover, wheat straw, switchgrass and miscanthus -- at a national level.

According to the study, not only would this require producing about a billion tons of biomass every year in the U.S., it would also mean using a part of the available land currently enrolled in the Conservation Reserve Program for energy crop production, which could significantly increase biomass production and keep biomass costs low.

"Most studies only tell you how much biomass is potentially available but they don't tell you how much it's going to cost to produce and where it is likely to be produced," Khanna said.

"Our economic model looks at some of the major feedstocks that could produce biomass at various prices."

Khanna and her team concluded that high-yielding grasses such as miscanthus are needed to achieve the 30 percent replacement goal, "but even then it's going to be a fairly expensive proposition," she said.

When miscanthus is added to the mix, the goal of 1 billion tons of biomass can be achieved, but at a cost of more than $140 per ton.

"Most studies consider costs in the range of $40 to $50 per ton, which is fine when we're talking about biomass production to meet near-term targets for cellulosic biofuel production," Khanna said. "But if we really want to get to the 30 percent replacement of gasoline, at least with the current technology, then that's going to be much more costly."

According to Khanna, miscanthus has been excluded from previous studies because it's a crop that has yet to be grown commercially, and most of the research about it is recent and still considered experimental.

"But across the various scenarios and prices our model considered, miscanthus has the potential to provide 50 to 70 percent of the total biomass yield," she said. "In most parts of the U.S., miscanthus is cheaper to produce than switchgrass, making it a very promising high-yield crop."

The study also contends that the economic viability of cellulosic biofuels depends on significant policy support in the form of the biofuel mandate and incentives for agricultural producers for harvesting, storing and delivering biomass as well as switching land from conventional crops to perennial grasses.

"Unless biomass prices are really high, these perennial grasses are going to have a hard time competing with crops like corn, soybean and wheat for prime agricultural land," Khanna said. "The economics works in favor of using the marginal, less productive lands, where corn and soybean productivity is much lower. But even then there are limits as to how much we would like to use that land for biomass. The more efficiently we can use the land, the better."

With biofuels, there's also the common perception that there's an unavoidable trade-off between fuel and food, Khanna said.

"That concern is much more prevalent when we talk about first-generation biofuels like corn-based ethanol," she said. "But for second-generation fuels, you can use crop residues as well as dedicated energy crops that can be grown on marginal land. This reduces the need to divert cropland away from food crop production. I'm optimistic that we can get considerable amounts of biomass without disrupting food production."

But relying on crop residues alone won't be sufficient to scale production up to levels set by the Energy Independence and Security Act of 2007, which limits the production of corn ethanol to 56 billion liters after 2015, and mandates the production of at least 80 of the 136 billion liters of ethanol from non-corn starch-based cellulosic feedstocks by 2022.

"Crop residue yields tend to be relatively low per unit of land -- 2 to 3 tons per hectare," Khanna said. "That can get costly pretty quickly. There are also concerns about how much you want to take away because at some point it has a negative effect on soil productivity as well as water quality because it affects run-off. So there are limits to crop residues, which is why we have to take a closer look at energy crops."

Because even marginal land is costly and has some alternative use, both now and in the future, using it as efficiently as possible means focusing more on the highest-yielding energy crops, Khanna said.

"Clearly the way to go is with the high-yielding grasses, which means switchgrass and miscanthus, but what we found is that it's not going to be a single feedstock but really a mix of feedstocks," she said.

Different regions of the country have a comparative advantage in different types of feedstocks.

"Corn stover is more common in the upper Midwest and West, whereas miscanthus is more prevalent in the southern part of the country and switchgrass in the real northern and southern areas," Khanna said.

The research was supported by the U.S. Department of Energy, National Science Foundation, and the U. of I. Energy Biosciences Institute. Other co-authors are Hayri Önal, a professor of agricultural and consumer economics at Illinois, and research associates Xiaoguang Chen and Haixiao Huang, of the Energy Biosciences Institute.

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Público, 2011.02.20
Declarações do presidente do Banco Mundial

 


Os preços das matérias-primas alimentares já estão num nível de alerta e poderão gerar mais instabilidade política. O aviso foi ontem feito pelo presidente do Banco Mundial, Robert Zoellick, à margem do encontro dos ministros das Finanças e dos banqueiros centrais em Paris.

"Atingimos um nível de alerta", disse Zoellick à imprensa, reproduzindo as declarações que fez ontem aos representantes dos 20 países ricos e emergentes, e que representam cerca de 85 por cento da riqueza do planeta. De acordo com o presidente do Banco Mundial, a subida dos preços dos alimentos vai incentivar o aumento da produção agrícola, mas, nos próximos dois anos, poderá contribuir para um aumento da instabilidade e até para a queda de alguns governos. A escalada das matérias-primas tem estado por detrás dos movimentos de protesto no Médio Oriente e no Norte de África.

"Devemos ser muito sensíveis ao que se passa em termos dos preços dos alimentos e aos efeitos que podem ter na estabilidade política", avisou Zoellick, apelando para que os dirigentes do G20 "considerem a alimentação como uma prioridade em 2011".

De acordo com dados recentes da instituição, a escalada dos preços dos alimentos atirou mais 44 milhões de pessoas para uma situação de pobreza extrema entre Junho e Dezembro. O cenário é mais grave nos países em desenvolvimento, onde as populações são mais vulneráveis às oscilações de preços, porque cativam mais de metade do seu rendimento para a compra de alimentos. A.R.F.

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World Bank Food Price Watch Feb 2011

por papinto, em 20.02.11
Food Price Watch Feb 2011 Final Version

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Alteracoes_climaticas

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Naturlink, Ana Ganhão (14-02-11)

 

 

 

A Checklist da flora vascular de Portugal Continental e Insular foi disponibilizada e formalmente adoptada pelo ICNB sendo parte integrante do inventário da biodiversidade.

Em Novembro de 2007 foi acordado entre a Direcção da ALFA e o Instituto da Conservação da Natureza e da Biodiversidade (ICNB) a elaboração da Checklist da Flora de Portugal (Continental, Açores e Madeira). Após quase 3 anos de trabalho, a ALFA – Associação Lusitana de Fitossociologia, apresentou publicamente a Checklist durante os VIII Encontros Internacionais de Fitossociologia.
Uma checklist de flora é, por definição, um trabalho inacabado. A nomenclatura, a taxonomia e a corologia botânicas estão, permanentemente, sujeitas a adições e correcções. Todos os anos são descobertos no território nacional novos taxa indígenas e naturalizados previamente descritos, reinterpretados muitos outros, ou corrigidos os seus nomes em acordo com as regras do ICBN (Código Internacional de Nomenclatura Botânica).

A bibliografia mais recente prova que o trabalho de descrição de novas espécies e taxa subespecífico em Portugal continental e insular não está terminado. Por conseguinte, a utilidade de uma checklist depende da sua contínua actualidade taxonómica e nomenclatural.
Tendo em consideração a velocidade a que são publicadas as novidades anteriormente referidas, é conveniente que uma checklist de flora seja actualizada em ciclos não superiores a um ano.
Gerir 4000 taxa, e muitos mais nomes, é uma tarefa exigente.

A ALFA disponibiliza a todos os interessados em colaborar nos trabalhos de actualização um endereço de e-mail dedicado (alfachecklist@gmail.com). As propostas de alteração aceites, e os respectivos autores, serão devidamente divulgados no site da ALFA. Fica assim feito o anúncio de uma etapa importante da história recente da botânica portuguesa e um pedido de colaboração que os botânicos, amadores ou profissionais, não devem (não podem) recusar.

Fonte: http://www3.uma.pt

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Um guia para conhecer Monsanto

por papinto, em 14.02.11
Um guia para conhecer Monsanto
14/02/2011
Redacção Planetazul
Vai ser hoje lançado, pelo presidente da Câmara Municipal de Lisboa, António Costa, e pelo vereador dos Espaços Verdes, José Sá Fernandes, às 18 horas, no Salão Nobre dos Paços do Concelho, o Guia do Parque Florestal de Monsanto.

“Em Ano Internacional das Florestas, esta é uma forma de Lisboa prestar homenagem à sua [floresta], com a publicação de uma obra que reúne a vasta história do Parque Florestal de Monsanto, desde a sua plantação há mais de 70 anos até à actualidade”, lê-se no comunicado enviado pela autarquia.

Neste livro de cerca de 170 páginas é possível encontrar “informação pormenorizada sobre o património vegetal, animal, patrimonial e cultural do principal espaço verde de Lisboa, com cerca de 200 fotografias, ilustrações e mapas”.

“Para além de prestar um tributo a todas as pessoas que contribuíram para a criação e manutenção desta floresta de Lisboa, e dos respectivos equipamentos de uso público, este guia convida os leitores a usufruírem de Monsanto e a conhecerem a sua história, a geomorfologia, as plantas, os animais, os cogumelos”, explica o prefácio do livro.

A apresentação de hoje conta com a presença do professor Fernando Catarino, antigo director do Jardim Botânico da Universidade de Ciências de Lisboa.


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Drinking habits

por papinto, em 14.02.11

 

Feb 14th 2011, 13:01 by The Economist online

 

 

A map of world alcohol consumption

THE world drank the equivalent of 6.1 litres of pure alcohol per person in 2005, according to a report from the World Health Organisation published on February 11th. The biggest boozers are found in Europe and in the former Soviet states. Moldovans are the most bibulous, getting through 18.2 litres each, nearly 2 litres more than the Czechs in second place. Over 10 litres of a Moldovan's annual intake is reckoned to be 'unrecorded'  home-brewed liquor, making it particularly harmful to health. Such moonshine accounts for almost 30% of the world's drinking. The WHO estimates that alcohol results in 2.5m deaths a year, more than AIDS or tuberculosis. In Russia and its former satellite states one in five male deaths is caused by drink.

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'Portugal Fresh'

por papinto, em 13.02.11

'Portugal Fresh' é o nome da nova entidade que vai promover o sector das frutas, legumes e flores em Portugal e no estrangeiro. A escritura pública de constituição da nova agência foi assinada a 6 de Dezembro.

Trata-se de uma associação de empresas do sector das frutas, hortícolas e flores, à qual podem pertencer também, a título consultivo, entidades públicas e privadas que contribuam com conhecimento científico e informação. A acção desta agência inclui participação em certames da especialidade; dar informação actualizada e quantificada (preços, quotas de mercado) aos associados; realizar e divulgar estudos dos mercados alvo de exportação; facilitar o acesso a mercados fora da União Europeia no que respeita a barreiras alfandegárias e legais; criar e tornar acessível uma plataforma de consulta dos preços dos produtos ao longo da cadeia de abastecimento, entre outras. A primeira acção da 'Portugal Fresh' é a organização da participação portuguesa na feira Fruit Logistica, em Berlim, na Alemanha, de 9 a 11 de Fevereiro, de 2011, onde cerca de 20 empresas vão expor no stand colectivo de Portugal.

in: http://www.flfrevista.pt/

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The economist | Feb 11th 2011, 11:50 by N.V. | LOS ANGELES

FOR decades, your correspondent has watched, with more than casual interest, every new twist and turn in the quest for an “artificial leaf”. His hope has been that industry might one day replicate the photosynthetic process used by plants, and thus create forests of artificial trees for making hydrocarbon fuel direct from sunlight. Apart from helping offset the emission of carbon dioxide caused by burning fossil fuels, such man-made leaves could provide an endlessly supply of energy for transport. Finally, it seems, something is stirring in the forest.

In his recent State of the Union address, President Obama drew special attention to the $122m research programme on artificial photosynthesis that is underway in laboratories across California. “They’re developing a way to turn sunlight and water into fuel for our cars,” said the 44th president. He might have added that the Joint Centre for Artificial Photosynthesis (JCAP), involving some 200 scientists and engineers from universities and research laboratories around the state, was seeking to make liquid hydrocarbons not from solar-powered electrolysis, biomass, micro-organisms or other round-about routes, but direct from sunlight—just as the chlorophyll in a leaf does.

Sunlight is the world’s largest source of carbon-neutral power. In one hour, more energy from the sun strikes the Earth than all the energy consumed by humans in a year. Yet, solar energy, in the form of sustainable biomass, provides less than 1.5% of humanity’s energy needs. Meanwhile, solar panels contribute a mere 0.1% of electricity consumption.

The problem is that the sun does not shine all the time. Night intervenes. So do clouds. If people are to rely on the sun for more of their energy, then a reliable form of storage is required. And the best way to store solar energy is to convert it into chemical fuel. That is what nature has been doing for millions of years.

Unfortunately, artificial photosynthesis is still in its infancy. Researchers reckon that, at least in the laboratory, they can make fuel direct from sunlight far more efficiently than can the fastest-growing plants. But no-one can yet do so at a cost that would make the process economic. Nor can they make it robust enough to work continuously, year in and year out, under the full glare of the sun. And they are years away from integrating the various steps—from capturing the sunlight in the first place to producing the finished fuel—into working prototypes, let alone commercial-sized factories capable of producing something resembling petrol.

Nevertheless, chlorophyll—the stuff of life—is as good a place as any to start. This large organic molecule has a magnesium ion at its core, surrounded by a ring of porphyrin. In nature, porphyrins are a group of organic pigments that give plants, corals and even animal skins their colours. One of the most common porphyrins is heme, the pigment in red blood cells. The porphyrin in chlorophyll absorbs strongly in the red and blue-violet parts of the visible spectrum, but not in the green. By reflecting such wavelengths, chlorophyll gives plants their colour.  

It would be better, of course, if chlorophyll could absorb light across the whole of the visible spectrum. But plants take what they have been given. As such, chlorophyll’s job is to absorb all the energy it can from sunlight, and use it to transform carbon dioxide from the atmosphere and water from the soil into carbohydrates and oxygen. The energy stored this way is what makes it possible for practically all living things to survive and thrive.

What makes chlorophyll so good at capturing sunlight is the way its ring-like structure can lose and gain electrons easily. When a leaf absorbs photons from sunlight, electrons in the chlorophyll molecules get excited from lower energy states into higher ones, allowing them to migrate to other molecules. That forms the starting point for chains of electron transfers that end with electrons being "donated" to molecules of carbon dioxide. Meanwhile, the chlorophyll molecules that gave up electrons in the first place accept electrons from elsewhere. These form the end points of transfer processes that start with the removal of electrons from water.


In this way, chlorophyll acts as a catalyst that drives the oxidation-reduction reaction between carbon dioxide and water to produce carbohydrates and oxygen. In the pursuit of the artificial leaf, then, the main task is to find catalysts that can mimic the intricate dance of electron transfers that chlorophyll makes possible.

The JCAP programme, led by the California Institute of Technology in Pasadena in partnership with the Lawrence Berkeley National Laboratory near San Francisco, will run for five years. The goal is to demonstrate a working solar-fuel generator that uses no biological components and no pricy catalysts (like platinum), yet can produce hydrocarbon fuel from the sun ten times more efficiently than maize (corn), sugar cane, switch grass or any other fast-growing crop.

To do so, the JCAP team will need to perfect a host of different components—including light absorbers and catalysts, molecular linkers to couple the two together, and special membranes for selectively separating the oxygen and hydrogen produced during the process. Two different catalysts are required: one to split water into hydrogen and oxygen; another to convert carbon dioxide and hydrogen into hydrocarbons. The various components for doing this will then need to be engineered into a practical bench-top system for demonstrating not only that solar fuel can be made efficiently and economically, but also that the process can be scaled up for commercial application.

At present, the JCAP team uses a carpet-like structure of microfibres made of a silicon-based semiconductor similar to those employed in photovoltaic solar panels. But instead of generating electricity, the charge-carriers produced by the semiconductor drive the catalytic process for splitting water into hydrogen and oxygen. Special membranes vent the oxygen away, while collecting the hydrogen. Later, other catalysts will be used to convert carbon dioxide and hydrogen into basic fuels such as methane and methanol. Long-term, the goal is to make "drop-in" replacements for petrol, or even diesel.

Before that can happen, however, cheap catalysts will have to be found. Platinum is excellent for splitting water into storable hydrogen and oxygen, but it is far too expensive to use on a commercial scale. A more practical substitute has been developed at the Massachusetts Institute of Technology, where Daniel Nocera and his colleagues have perfected cheap and durable catalysts based on cobalt and phosphate, and, more recently, on nickel and borate.

Last year, Sun Catalytix, a Massachusetts-based company founded by Dr Nocera, was awarded a $4m contract by the Department of Energy to commercialise the process. The company aims to develop solar-fuel stations for places that are off the electricity grid, and eventually for the home. Meanwhile, the JCAP team in California is working on its own light absorbers and catalysts. So far, it has released few details—though it admits it needs to develop cheaper versions of what it is currently using.

But the dark horse in the race to develop a synthetic chlorophyll could be a small group at Massey University in New Zealand. Wayne Campbell, at the university’s Nanomaterials Research Centre, has come up with a series of porphyrin dyes that work with solar cells based on titanium dioxide rather than silicon. In the laboratory, Dr Campbell’s cells are said to generate electricity for a tenth the price of conventional photovoltaic panels.

There is talk of incorporating them into roofing materials and tinted windows. But if Dr Campbell’s porphyrin dyes are as efficient as claimed, they could prove to be better catalysts for producing solar fuel for motor cars, as well as electricity for homes. Your correspondent is gratified to see that artificial leaves are sprouting everywhere—and promising to make the world a greener place.

 

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