'Huge airships to carry freight starting 10 years from now'

Carbon emissions in an airship-cargo future would be ... 99.9% of what they are now. Woo!

That's debatable ground. Some analysts believe that an airliner's carbon is no worse, kilogram for kilogram, than carbon emitted down on the ground. Recent research says that the warming effect at height is enhanced by a factor of no more than 1.2 or 1.9. Even the reliably alarmist IPCC hasn't gone higher than a range of 2 to 4. (Full details with references on page 3 of this pdf.)

The SkyCat airship men seem to have calculated that a jet burning a given amount of fuel is no less than six times as damaging as an airship burning the same amount, in order to obtain their 90 per cent greenhouse effect reduction. Let's be a bit more reasonable and say 50 per cent - that's still great news for the planet, isn't it?

Not really. The whole of aviation accounts for only three per cent of emissions, and we're talking here about 40 per cent of air freight (which in turn is at most 25 per cent of aviation). So bringing in airships to replace all dedicated cargo planes would drop carbon emissions to ... approximately 99.9 per cent of what they were before.

If you want you could bump up aviation to 10 per cent of emissions - anti-flying people often like to, though this is based on some fairly wild assumptions. That might change the airship-freight-future carbon figure to 99.5 per cent of current: but then in reality an awful lot of air cargo can't usefully be shipped at 75 mph. So actually, no: you're talking about a minuscule impact no matter how you slice things up.

The environmental benefit here is basically nil. And the environmental benefit argument is the only new thing here, the only additional factor which might motivate big business towards airships and away from jets. The rest of Professor King's report is little more than a not-very-detailed rehash of airship ideas in recent times - and not always a completely accurate one, either. The prof and his colleagues, for instance, believe that the Lockheed P-791 prototype ship, built to contend for the DARPA "Walrus" project, is "undergoing flight tests".

Sadly it isn't. Walrus was cancelled in 2006, and the P-791 has been sitting idle in mothballs at Lockheed's "Skunk Works" for years. The active, funded airship projects at the moment - LEMV and ISIS - aren't Walrus type heavy lift low-altitude ships at all, and aren't really relevant here.

Much as it pains us to say it, there's nothing to see here. Airship lovers will probably be waiting a lot more than ten years to see the great sky-vessels return, it would seem. ®

Bootnote

Just to clear up a few points:

¹A blimp is the term for a dirigible airship (not a free-floating or tethered balloon) whose fabric envelope maintains its shape by being inflated at a slightly higher pressure than the air around it. Blimps above a certain size become very difficult to make, and thus blimps could probably never be serious cargo haulers. In the grand old days, large airships were either semi-rigids - perhaps a blimp with a stiffening keel - or more commonly proper rigids. These latter enclosed a series of gas bags inside a vast, lightweight structure of girders and wires.

²Airships are not "powered" by helium, its buoyancy is merely used to support all or some of their weight. They still need ordinary motive power to move about.

³There is no such thing as "a graf zeppelin". Zeppelin is an alternative term for "airship", especially one manufactured by Graf [Count] von Zeppelin's original German venture - or its modern successor company. One such ship, the vessel which circumnavigated the globe in 1929, was named Graf Zeppelin in the old Count's honour. "A zeppelin" or "the Graf Zeppelin" would have been fine. Aargh!

⁴The Hindenburg was not a blimp and nor did she put an end to any "craze" for blimps. Her demise (in which 35 of the 97 people on board died) brought to an end the era of the rigid airship. Blimps continued in use and were employed in large numbers by the US Navy through World War II and beyond.