The Guardian has a somewhat far-fetched article on the prospects for airships replacing planes - Blimps could replace aircraft in freight transport, say scientists.

Fresh fruit, vegetables, flowers and other foreign luxuries could be part of a global revolution by carrying cargo around the world in airships instead of planes, one of the UK's leading scientists has predicted.

The government's former chief scientific adviser, Professor Sir David King, now director of the Smith School of Enterprise and Environment at the University of Oxford, told a conference that massive helium balloons – or blimps – would replace aircraft as a key part of the global trade network as a way of cutting global warming emissions.

Despite languishing in sci-fi B-movies for most of the last 70 years, King said several major air and defence companies, including Boeing and Lockheed Martin, were working on designs, and the US defence department had recently made a large grant to help develop the technology.

As a result, the helium-powered ships could be carrying freight – and even passengers – in as little as a decade's time, King told the Guardian. "There are an awful lot of people we talk to who say this is going to happen," said King. "This is something I believe is going to happen."

King was speaking this week at the World Forum on Enterprise and the Environment in Oxford, which has made transport a major focus of debate about global efforts to cut the greenhouse gas emissions from burning fossil fuels, which are a major contributor to global warming and climate change. In Europe 22% of greenhouse gases are from transport, compared with 28 from heat and electricity, 21% from industry and construction and 9% each from agriculture and homes, according to the European Environment Agency.

The New York Times has an article on the liftoff of the airship industry. I'm always reminded of the flying party when I see these things being promoted.

Imagine gliding in a floating hotel over the Serengeti, gazing down at herds of zebra or elephants; or floating over Paris as the sun sets and lights blink on across the city as you pass the Eiffel Tower.

Such flights of fancy may one day be possible, if the dream of Jean-Marie Massaud, a French architect, comes true.

As the cost of fuel soars and the pressure mounts to reduce carbon dioxide emissions, several schemes for a new generation of airship are being considered by governments and private companies. “It’s a romantic project,” said Mr. Massaud, 45, sitting amid furniture designs in his Paris studio, “but then look at Jules Verne.”

It has been more than 70 years since the giant Hindenburg zeppelin exploded in a spectacular fireball over Lakehurst, N.J., killing 36 crew members and passengers, abruptly ending an earlier age of airships. But because of new materials and sophisticated means of propulsion, a diverse cast of entrepreneurs is taking another look at the behemoths of the air. ...

In Germany, Deutsche Zeppelin-Reederei, the successor to the operator of the Hindenburg, has had success with a new generation of airship it uses to transport sightseers and scientific payloads.

The trend is not entirely new. Zeppelin-Reederei carried 12,000 passengers on sightseeing tours over southern Germany last year. Aerophile, a French company that revived tethered balloons, which compete with dirigibles as carriers of passengers, advertising and scientific instruments, was founded by two young French engineers in 1993.

The aircraft industry is not exactly bracing for a dogfight. Mr. Massaud says that Emirates and Air France have expressed interest in Manned Cloud. But with top speeds of around 100 miles an hour and a maximum capacity of several dozen passengers, dirigibles are expected by most aviation experts to remain niche vessels for ferrying tourists, advertising and occasional scientific payloads.

“A dirigible is something magical,” said Jérôme Giacomoni, who was 25 when he founded Aerophile with a friend. “But most of the ideas are crazy.”

Dirigibles, he said, “are very sensitive to storms. Their size requires large landing spaces; economically they’re not feasible.”

Not yet, say dreamers like Mr. Massaud. But gasoline prices are pushing airlines to reduce the number of flights and retire older, less fuel-efficient aircraft. Aircraft manufacturers like Boeing and Airbus have responded by promising planes that use less fuel and produce less carbon dioxide.

KimiK pointed out in a comment on my Steampunk post that George Monbiot has been singing the praises of dirigibles lately In his article "Travelling Light", George considers the question "Is the airship a viable alternative to jet travel?".

Of all the charges levelled against environmentalists, perhaps the most unfair is the accusation that we are opposed to technological change. Most of the greens I know are fascinated by gadgets (sometimes to the exclusion of better solutions), while some of the people we confront seem terrified by new technologies, and react to them - witness the campaigns against windfarms - with irrational hostility.

But because environmentalists tend to have a feeling for material constraints, we recognise that solutions cannot be conjured out of thin air. In some cases they just don’t appear to exist. There are two reasons why we make such a fuss about flying. The first is that, even as governments promise to cut emissions, everywhere airports are expanding. In the UK, the government expects the number of airline passengers to rise from 228 million in 2005 to 480 million in 2030. Before long, there will scarcely be a patch of sky without a jet in it. The other is that there are no alternative means of propelling people through the air which are not more destructive than burning ordinary aviation fuel. Or so we think.

The airline companies prescribe two cures that are even worse than the disease. Even before they are deployed commercially in jets, biofuels are spreading hunger and deforestation. At first sight, hydrogen seems more promising. If it is produced by electrolysis using renewable electricity, it’s almost carbon-free. The prohibitive issue is storage. Hydrogen contains just a quarter of the energy as the same volume of jet fuel (kerosene), which means that planes could fly long distances only if they were filled with gas rather than passengers or cargo.

This means that if hydrogen planes are to fly commercially, they need much wider bodies than ordinary jetliners. According to the Royal Commission on Environmental Pollution “the combination of larger drag and lower weight would require flight at higher altitudes” than planes fuelled by kerosene. A technology that is green at ground level becomes an environmental disaster in the stratosphere. Hydrogen’s great advantage – that it produces only water when it burns – turns into a major liability: in the stratosphere, water vapour is a powerful greenhouse gas. The royal commission estimates that hydrogen planes would exert a climate changing effect “some 13 times larger than for a standard kerosene fuelled subsonic aircraft.”

But there is another use for this gas, though I am aware that it will go down like a lead balloon with most of my readers. The word airship elicits a fixed reaction in almost everyone who hears it: “what about the Hindenburg?”. It’s as if, every time someone proposed travelling on a cruise ship, you were to ask, “but what about the Titanic?”. Yes, there was a spectacular disaster – 71 years ago. It has lodged in our minds because, like the Titanic, the Hindenburg was bigger and plusher than any craft built before it, and it was carrying rich and prominent people. The conflagration was witnessed by journalists and broadcast all over the world. It also become the technology’s funeral pyre: the Hindenburg was doomed long before it burnt, as airships were already being displaced by aeroplanes.

Though the designs have changed, their disadvantages have not disappeared. While a large commercial airliner cruises at about 900 kilometres per hour, the maximum speed of an airship is roughly 150kph. At an average speed of 130kph, the journey from London to New York would take 43 hours. Airships are more sensitive to wind than aeroplanes, which means that flights are more likely to be delayed. But they have one major advantage: the environmental cost could be reduced almost to zero.

Even when burning fossil fuels, the total climate-changing impact of an airship, according to researchers at the Tyndall Centre for Climate Change Research, is 80-90% smaller than that of ordinary aircraft. But the airship is also the only form of transport which can easily store hydrogen: you could inflate a hydrogen bladder inside the helium balloon. There might be a neat synergy here: one of the problems with airships is that they become lighter - and therefore harder to control - as the fuel is consumed. In this case they become heavier. Michael Stewart of the company World SkyCat suggests burning both gaseous and liquid hydrogen to keep the weight of the craft constant.

Airships fly much lower than planes – typically at about 4000 feet – which means that their emissions of water vapour have very little effect on temperature. If they were powered by hydrogen fuel cells, they would be almost silent, greatly reducing the effects for people on the ground. Though they are slower than jets, the cabin can be built much wider, which means that travelling by airship would be rather like travelling by cruise ship, but at twice the speed and using a fraction of the fuel.

There are four small companies trying to get airships off the ground. Most of the new designs make use of aerodynamic lift as well as buoyancy (they are shaped like fat planes with stubby wings or tails) which means that they are heavier and more stable than the old dirigibles, and can land without help on the ground. They can alight on and take off from almost any flattish surface, including water. But all of them have a problem with flotation: of the financial rather than the physical kind. While the price of carbon stays low, companies have no financial incentive to switch to a different form of transport.