POSTAIS DA BAIXA: Natal na Rua da Prata

Há qualquer coisa de muito absurdo quando no final de cada ano a CML pendura decorações de Natal nos arruamentos decadentes da Baixa. A degradação dos edifícios pombalinos, com a pele das suas fachadas cobertas de podridão e poluição, não consegue responder aos sinais festivos que a autarquia atira para o ar. É uma cidade a preto e branco - sendo que o preto tem origem no trânsito automóvel.

Túnel do Marquês, em Lisboa, é o lugar mais poluído de Portugal

De cada vez que um automobilista entra ou sai de Lisboa à hora de ponta através do Túnel do Marquês está a atravessar o lugar mais poluído do país.

A conclusão consta de um estudo do Instituto Superior de Engenharia de Lisboa (ISEL) a que o i teve acesso. Os níveis de poluição no interior desta passagem são dez vezes superior ao limite legal. Enquanto que, nas principais zonas urbanas da capital, a média de partículas na atmosfera ronda os 50 microgramas por metro cúbico, dentro do túnel esse valor dispara para 500 microgramas.

"As emissões de CO2 na atmosférica preocupam a generalidade das pessoas, mas as partículas são os constituintes mais perigosos para a saúde pública", adverte Manuel Matos, engenheiro ambiental do ISEL e coordenador do estudo. Por serem pequenas, as partículas infiltram-se rapidamente nos pulmões e são absorvidas na corrente sanguínea, originando um leque alargado de doenças respiratórias e pulmonares.

Mas as partículas encontradas no Túnel do Marquês são ainda mais perigosas porque 80% da sua composição é carbono. Isto significa que boa parte do ar que se respira dentro do túnel é composto por restos de combustível queimado, metais libertados pela parte mecânica dos automóveis e ainda resíduos que se soltam dos catalisadores: um cocktail de fragmentos propícios para outro leque alargado de doenças cancerígenas.

A poluição é um fenómeno associado a quase todas as passagens subterrâneas rodoviárias, mas no caso do Túnel do Marquês o problema agrava-se uma vez que se conjugam duas características perigosas: "É demasiado comprido e tem um elevado declive", explica o especialista.

O Túnel do Marquês tem uma extensão total de 1725 metros e uma inclinação de 9% (o limite imposto pela União Europeia é de 5%). Cada uma destas particularidades tem uma consequência distinta nos níveis de poluição. A elevada subida que o túnel apresenta implica um maior esforço do carro, um maior gasto de combustível e, por fim, maiores quantidades de partículas libertadas para a atmosfera. O comprimento do túnel, por seu turno, significa que, nas horas de maior congestionamento de trânsito, o ar não circula: "Os automóveis em movimento encarregam-se de garantir a ventilação do túnel, mas quando estão parados no trânsito isso não acontece." E o que temos entre as 08h00 e as 10h00 e das 17h00 às 19h00 é um túnel cheio de carros a queimar combustível. O que é que se poderá fazer, então, para reduzir o nível de poluição no Túnel do Marquês? A resposta de Manuel Matos é desanimadora: "Há muito pouco a fazer, além de reduzir o número de carros que entra e sai do túnel.

"O Túnel do Marquês "até está bem equipado", defende o engenheiro ambiental. Tem ventiladores que disparam automaticamente quando a atmosfera fica turva e é lavado uma vez por mês. Mesmo assim, o estudo do ISEL faz várias recomendações: aumentar ainda mais o número de respiradores e proibir a circulação dos automóveis a diesel que, segundo o especialista, são os responsáveis por mais de metade da poluição dentro do túnel. Porém, todas estas medidas não passam de remendos, adverte Mário Matos: "A única solução passa por restringir o uso do carro". É, aliás, isso que acontece durante os fins-de-semana. Aos sábados e domingos, os valores das partículas dentro do túnel descem para quase metade, fixando-se em média nos 200 microgramas por metro cúbico: "É essa comparação que nos permite fazer a correlação entre a poluição e o volume de tráfego automóvel", remata o engenheiro ambiental.

As amostras para o relatório do ISEL foram recolhidas em Outubro de 2008, mas os resultados nunca foram apresentados em Portugal. O estudo, que teve o apoio da Câmara de Lisboa, apenas foi apresentado em 2009 na Áustria. Porém, o vereador Fernando Nunes da Silva, responsável pelo pelouro do Ambiente, disse ao i desconhecer estas conclusões e considera "estranhos" os resultados: "O túnel foi sujeito a um estudo de impacto ambiental e o tráfego previsto era muito superior ao que lá circula. Foram introduzidos limites de velocidade de 50 km/h que estão a ser respeitados. Acho muito estranho que um estudo de impacto ambiental elaborado por nomes sonantes da engenharia do ambiente conclua que não existe problema e vem agora um estudo dizer o contrário", rematou.

(jornal «i»).

THE CARBON COUNTER: Times Square billboard counts Carbon build up

National debt used to be the big number we all lived in fear of. Now it's greenhouse gases.

Climate change is likely to have all sorts of nasty consequences over the next century—among them, according to a brand-new report from the U.S. Global Change Research program, an increase in torrential downpours in the American northeast.

So it was uncomfortably fitting that a major climate-consciousness-raising event took place in just such a downpour. As reporters and dignitaries huddled under leaky tents just outside New York's Madison Square Garden on Thursday, Deutche Bank switched on its mammoth Carbon Counter billboard. The counter, towering 70 feet above busy Seventh Avenue and dramatically visible to hundreds of thousands of commuters who take the train to and from Penn Station, displays a real-time count of heat-trapping greenhouse gases we're pumping into the atmosphere—about 2 billion metric tons every month, added to the 3.6 trillion tons already floating around up there.

How do they know it's 2 billion tons? Actually, they know it isn't. Although carbon dioxide is by far the most significant human-generated greenhouse gas, it isn't the only one. Methane, generated by ruminating cows and rice paddies is another; nitrous oxide, created in making fertilizer, is another; so are halocarbons, used as refrigerants. If you really want to know about how much heat we're trapping, you have to take these into account too—and that's what Deutche Bank and its scientific advisers from MIT wanted to do.

It's complicated, though. For one thing, each of these gases traps heat at a different rate (OK, they really trap infrared radiation, but it ends up amounting to the same thing). Methane, for example, is a much more efficient energy-trapper than CO2; it's just that we emit a lot less of it. Each of these gases, moreover, degrades in the atmosphere at a different speed. That means you can't just add them up. "It's like you give someone a hundred dollars," says MIT atmospheric scientist Ron Prinn, "but it's a mix of Australian and Canadian and U.S. dollars. "You have to make some conversions before you know what it's worth." For the Carbon Counter, those conversions run into many pages of equations, at the end of which you get a number representing the "CO2 equivalent" of 20 different gases. Add them up, and you're at 2 billion tons monthly.

That's a big number, certainly, but what exactly does it mean? Most popular accounts of climate change don't talk about tons; they talk about parts-per-million—the number of CO2 or other molecules you'd find in a million molecules of atmosphere. CO2 was at about 280ppm back in 1700; it's now at 386 and rising. For perspective, climate scientists believe that if CO2 rises to 450ppm or so, the global average temperature could rise as much as 2 degrees Celsius, with serious consequences (and heavy rainstorms are hardly the worst).

But if you factor in the other greenhouse gases, we're already at 450, or pretty close to it. That being the case, you'd think we'd already be seeing dramatically rising seas and severe weather changes. There are two reasons why we aren't. First, it takes a while for heat to build up once the gases are up there. Second, and more important, the Carbon Counter doesn't take aerosols into account. These are tiny particles of soot, sulfur dioxide and other pollutants spewed into the air along with greenhouse gases. "The problem with these," says Bill Chameides, dean of Duke University's Nicholas School of the Environment, "is that some aerosols tend to cool the planet, some tend to warm it, and some interact with clouds in ways we don't understand."

That's the good news. The bad news is that aerosols cause their own problems— lung disease and acid rain, just to name a couple. Presumably, we'll be trying to limit those emissions in the future, which will leave the greenhouse gases to do their thing without interference.

By leaving some factors out, the Carbon Counter is by definition somewhat inaccurate. But since most of us don't know what 3.6 trillion tons of carbon or carbon-equivalent or whatever actually means, it hardly matters. It's a big number, and it's getting bigger, fast. Deutche Bank and the MIT folks hope that seeing these huge numbers scroll by on a giant billboard will make people more aware of what we're doing to the planet, just as billboards with the U.S. national debt try to raise awareness about another scary number.

Given how much people pay attention to the debt, though, let's hope this one is more effective.

In NEWSWEEK, 19 de Junho de 2009

http://www.newsweek.com/id/202757?from=rss

Foto: O novo «carbon billboard» instalado em Times Square, Nova Iorque.

Nota: Vamos sugerir ao Presidente da CML, e ao Vereador do Ambiente, que instale semelhante painel em frente, por exemplo, da sede do ACP. Ou, em alteranativa, em vez da tela de publicidade da Renova no ROSSIO.

«Bicycle-sharing changing the face of Europe»

in INTERNATIONAL HERALD TRIBUNE, 9-11-2008

Barcelona: In increasingly green-conscious Europe, there are said to be only two kinds of mayors: those who have a bicycle-sharing program and those who want one.

Over the past several years, the programs have sprung up and taken off in dozens of cities, on a scale no one had thought possible and in places where bicycling had never been popular.

The sharing plans include not just Paris's Vélib', with its 20,000 bicycles, but also wildly popular programs with thousands of bicycles in major cities like Barcelona and Lyon. Programs operate in Pamplona, Spain; Rennes, France; and Düsseldorf. Even Rome, whose narrow, cobbled streets and chaotic traffic would seem unsuited to pedaling, recently started a small trial program, Roma-n-Bici, which it plans to expand soon.

For mayors looking to ease congestion and prove their environmental bona fides, bike-sharing has provided a simple solution: For the price of a bus, they get a fleet of bicycles, and they can avoid years of construction and the approvals required for a subway. For riders, joining means cut-rate transportation - as well as a chance to contribute to the planet's well-being.

The new systems are successful in part because they blanket cities with huge numbers of available bikes, but the real linchpin is technology. Aided by electronic smart cards and computerized bike stands, riders can pick up and drop off bicycles in seconds at hundreds of locations, their payments deducted from bank accounts.

"As some cities have done it, others are realizing they can do it, too," said Paul DeMaio, founder of MetroBike, a U.S.-based bike-sharing consultant that tracks programs worldwide. "There is an incredible trajectory."

The huge new European bicycle-sharing networks function less as recreation and more as low-cost, alternative public transportation. Most programs (though not Paris's and Lyon's) exclude tourists and day-trippers.

Here in Barcelona, streets during rush hour are lined with commuters and errand-goers on the bright red bicycles of Bicing, the city's 18-month-old bike-sharing program. Bicing offers 6,000 bicycles from 375 stands scattered every few blocks; all the bikes seem to be in nearly constant motion.

"I use it every day to commute - everyone uses it," said Andre Borao, 44, an entrepreneur in a gray suit with an orange tie, as he prepared to ride home for lunch. "It's convenient, and I like the perspective of moving through the streets."

The expanding program in Barcelona is typical of so-called third-generation programs that rely heavily on technology. (In its first generation, bike-sharing involved scattering old bikes around the streets of Copenhagen, where they could be used for free; second-generation programs accepted coins.)

Here, customers buy a yearly membership for about $30 and get a smart card that allows them to release a bike from a mechanized dock. The first 30 minutes are free, with a charge thereafter of 30 cents for each half-hour. Bikes must be returned within two hours, or members face smart-card deactivation, but they can be returned to any bike rack in the network.
Programs in Germany and Austria tend to work on a different system: Members receive cellphone text messages providing codes to unlock the bikes.

Cities like Copenhagen and Amsterdam have long been home to devoted bicycling commuters. But the new programs have created the greatest transportation revolution in central and southern Europe, where warmer climates allow riders to move about comfortably year-round. The shared bicycles in Barcelona, Lyon and Paris are heavily used - logging about 10 rides a day, according to officials in those cities.

In North America, issues like insurance liability, a stronger car culture, longer commutes and a preference for wearing helmets have slowed adoption of bicycle-sharing programs. None of the European programs mandate helmets. Still, Washington and Montreal are experimenting with small projects, and Chicago, Boston and New York are studying options.

Perhaps the best indication that bicycle-sharing has arrived is this: Shanghai, which 10 years ago was trying to eliminate bicycles from some of its boulevards to make way for cars, last month opened a pilot bike-sharing stand.

In most European cities, advertisers have been given contracts to set up and maintain bicycle-sharing programs in exchange for the rights to sell ads on city-owned space, like bus stations. "We provide a turn-key program," said Martina Schmidt, bike-sharing director of Clear Channel Outdoors, which now runs programs in 13 European cities and recently started its first American program, the one in Washington. "We give the city what they're looking for, and they give us space to sell."

Here in Barcelona, the Bicing program has had its glitches, reflecting, in part, its unexpected popularity.

On Barcelona's outskirts, users complain that bicycle stations (with up to 36 bikes) can run out toward the end of the morning rush hour, leaving customers temporarily stranded. Likewise, docking sites in central Barcelona are sometimes full, so riders have to search for parking. Car owners complain about the removal of parking spots to accommodate new bike lanes; the city has about 130 kilometers, or 80 miles, of lanes, a number that has rapidly expanded in the past two years.

Barcelona's central business district is in a geographic bowl compared with most residential neighborhoods, so while many people want to ride there to work, fewer want to ride a bike home. Directed by controllers at a command station, Bicing's 100 employees use trucks to rebalance the system, taking bikes to where they are needed. City officials seem a bit overwhelmed.

"For the moment, it will not grow anymore," said Ramón Ferreiro, an official with Bicing. "We now have to consolidate and start working so that maintenance is adequate, and improve the system at all levels."

Even with the growing pains, José Monllor, a graduate student, says he now rides to class instead of driving his car. "It stays in the parking lot," he said of his car. "It's stupid to drive."
The actual impact of bike-sharing on traffic or emissions is difficult to quantify because converts include people like Monllor, who would have driven, as well as those who would have taken public transportation.

Officials in Lyon, the first city to institute a massive technology-driven bike program, estimate that bike-sharing has cut carbon dioxide emissions by up to 8,000 tons since its inception in 2005. But more than that, they say, it has changed the face of the city.

"The critical mass of bikes on the road has pacified traffic," said Gilles Vesco, deputy mayor in charge of Lyon's program. "Now, the street belongs to everybody, and needs to be better shared. It has become a more convivial public space."