As you’d expect, it explains how to identify the main kinds of clouds. And reading it is like an epiphany – I find I’m looking up on the way to work, or while waiting for buses and trains. As Pretor-Pinney says, it’s a hobby you can take part in anywhere, and for as long or as little as you wish.
The nebulous nature of clouds means several share characteristics or even bits of the same name – alto, cirro, cumulo, nimbo, strato. I got even more list over which combinations merge into which other combinations, and then there’s the huge number of sub-species, features and effects. It’s no wonder the book comes complete with a cloudspotter’s diploma. (There are also copious plugs for the Cloud Appreciation Society, which the author founded.)
Mixed in with the scientific explanations and Latin etymology are a wealth of top facts. For example, I now know where the phrases “cloud nine” and “cloud cuckooland” come from. Yet, as well as the top facts, there’s far too many terrible jokes and asides which can get a little grating. Part of me wonders how much that stuff just pads it out, and how much the author or his editors feared scaring punters off with too much technicalia. The clutter of tangents and silly bits makes it harder to remember the clues to diagnosis. Of course, this is a book to carry with you and refer back to, but I’m a bit annoyed I don’t remember more as I went along.
The penultimate chapter is perhaps the most interesting, as it covers man-made clouds. First there’s the militaro-cloud technologies, as worked on by sci-fi writer Kurt Vonnegut’s brother Bernard. In the movie of the book I imagine him played by Andre Morrell (or his modern equivalent, which would be Ian McKellen). Anyway, back in the 1940s and 50s, Bernard K (not Bernard Kay. See, these asides are annoying!) studied how clouds formed, and that led to seeing if they could be influenced or controlled.
Soon the US Naval Weapons Center took over the funding of this research. According to Pretor-Pinney, this was because it was believed that the Russians were also investigating the same area – though he gives no evidence for this belief. I can’t help feeling it’s a good excuse to do stuff you want to do anyway. Can’t get permission to build atomic bombs, rocket to the moon or stock your museum with other people’s statues? Hell, just say, “But if we don’t, some foreigners will…”.
So what was the result of the militaro-clouds?
“Operational cloud seeding commenced on 20 May 1967 and continued for six years over parts of Laos, North Vietnam, South Vietnam and Cambodia, at an estimated annual cost of around $3.6 million a year. It is impossible to say whether it was really successful in increasing rainfall, since no systematic assessment of precipitation was made after the initial test phase, which itself could not be considered to be statistically rigorous.”
Gavin Pretor-Pinney, The Cloudspotter’s Guide, p. 264.Still, once the story got out that clouds were being developed as weapons, there was a bit of a rumpus. Some laws were passed to technically stamp out any further such projects. But, amazingly enough, the US has wriggled around its own legislation and Pretor-Pinney lists some unsettling developments.
More unsettling, though, is the second part of the same chapter, which addresses the clouds produced by plans. Condensation trails (or “contrails” if you wanna get with the lingo) have been the hot topic of debate for cloudies recently. There’d been some discussion anyway about how they influenced weather systems – affecting other clouds’ formation. And then, when US airplanes were grounded after 11 September 2001, eagle-eyed observers noticed that this pause seemed to have an affect on ground temperatures. Since then, it’s been shown that contrails “reduced ground temperatures during the day and raised them at night” (p. 274) – by as much a whole degree centigrade.
(Yes, that’s quite a lot.)
Pretor-Pinney is good at covering the different possible outcomes of this – it could add to global warming, it could lower temperatures – and also of the problems in trying to tackle it. Getting planes to fly lower would stop contrails forming, but would make them use up more fuel. So whichever way, the environment is shagged.
A little ironically, the final chapter sees Pretor-Pinney jetting off to the other side of the planet to see a cloud formation that’s also been seen over the English Channel. The “Morning Glory” is a miles-long tube of cloud that can clearly be seen cutting across the north of Australia in a wowing satellite image. Turns out that the place Pretor-Pinney goes to see it is Burketown, one of the dusty, ramshackle stop-offs on my brother’s trek across the outback.
Yes, he tells me, everyone talked about the “Morning Glory”. No, he admits, he wasn’t there at the right time to see it.