Weather with you: thundersnow, hosepipe bans and climate punditry

I must confess to have not watched any of the current BBC series The Great British Weather, since (a) it looks rubbish; and (b) I spend enough time comparing the short-range forecast with the view outside my window as it is, in order to judge whether it will be a suitable night for astronomy. Since buying a telescope at the start of the year (see an earlier astronomy-related post for more details) I've become just a little bit obsessed, but then as an Englishman it's my inalienable right to fixate on the ever-changeable meteorology of these isles. If I think that there is a chance of it being a cloud-free night I tend to check the forecast every few hours, which for the past two months or so has proved to be almost uniformly disappointing; as a matter of fact, the telescope has remained boxed up since early May.

There appears to be a grim pleasure for UK-based weather watchers that when a meteorology source states that it is currently sunny and dry in your location it may in fact be raining torrentially. We all realise forecasting relies on some understanding of a complex series of variables, but if they can't even get the 'nowcast' correct what chance do the rest of us have?

So just how has the UK's mercurial weather patterns affected the science of meteorology and our attitude towards weather and climate? As far back as 1553 the English mathematician and inventor Leonard Digges included weather lore and descriptions of phenomena in his A General Prognostication. Since then, British scientists have been in the vanguard of meteorology. Isaac Newton's contemporary and rival Robert Hooke may have been the earliest scientist to keep meteorological records, as well as inventing several associated instruments. Vice-Admiral Robert FitzRoy, formerly captain of HMS Beagle (i.e. Darwin's ship) was appointed as the first Meteorological Statist to the Board of Trade in 1854, which in today’s terms would make him the head of the Met Office; he is even reputed to be the inventor of the term 'forecast'.

Modern science aside, as children we pick up a few snippets of the ancient folk learning once used to inculcate elementary weather knowledge. We all know a variation of "Red sky at night, shepherd's delight; red sky in the morning, shepherd's warning", the mere tip of the iceberg when it comes to pre-scientific observation and forecasting. But to me it looks if all of us in ever-changeable Britain have enough vested interest in the weather (once it was for crop-growing, now just for whether it is a sunglasses or umbrella day – or both) to maintain our own, personal weather database in our heads. Yet aren't our memories and lifespan in general just too short to allow us a genuine understanding of meteorological patterns?

One trend that I consider accurate is that those 'little April showers' I recall from childhood (if you remember the song from 'Bambi') are now a thing of the past, with April receiving less rainfall than June. This is an innate feeling: I have not researched it enough to find out if there has been a genuine change over the past three decades. Unfortunately, a combination of poor memory and spurious pattern recognition means we tend to over-emphasise 'freak' events - from thundersnow to the day it poured down at so-and-so's June wedding - at the expense of genuine trends.

For example, my rose-tinted childhood memories of six largely rain-free weeks each summer school break centre around the 1976 drought, when my brother had to be rescued from the evil-smelling mud of a much-reduced reservoir and lost his shoes in the process. I also recall the August 1990 heat wave as I was at the time living less than 20 km from Nailstone in Leicestershire, home of the then record UK temperature of 37.1°C. In contrast, I slept through the Great Storm of 1987 with its 200+km/h winds and don’t recall the event at all! As for 2011, if I kept a diary it would probably go down as the 'Year I Didn't Stop Sneezing'. City pollution and strong continental winds have combined to fill the London air with pollen since late March, no doubt much to the delight of antihistamine manufacturers.

An East Anglian beach, August 2008

Our popular media frequently run stories about the latest report on climate change, either supporting or opposing certain hypotheses, but rarely compare it to earlier reports or long-term records. Yet even a modicum of research shows that in the Nineteenth Century Britain experienced a large variation in weather patterns. For example, the painter J.M.W. Turner's glorious palette was not all artistic licence, but almost certainly influenced by the volcanic dust-augmented sunsets following the 1815 Tambora eruption. It wasn't just painting that was affected either, as the UK suffered poor harvests the following year whilst in the eastern United States 1816 was known as 'Eighteen Hundred and Froze to Death'.

The influence of the subjective on the objective doesn't sound any different from most other human endeavours, except that weather professionals too - meteorologists, climatologists, and the like - also rely on biases in their work. Ensemble forecasting, which uses slightly different initial conditions to create data reports which are then combined to provide an average outcome, has been shown to be a more accurate method of prediction. In other words, this sounds like a form of scientific bet hedging!

Recent reports have shown that once-promising hypotheses involving singular factors such as sunspot cycles can in no way account for most primary causes of climate change, either now or in earlier epochs. It seems the simple answers we yearn for are the prerogative of Hollywood narrative, not geophysical reality. One bias that can seriously skew data is the period being used in a report. It sounds elementary, but we are rarely informed that even the difference of a single year in the start date can significantly affect the outcome as to whether, for example, temperature is increasing over time. Of course, scientists may deliberately only publish results for periods that support their hypotheses (hardly a unique trait, if you read Ben Goldacre). When this is combined with sometimes counter-intuitive predictions – such as that a gradual increase in global mean temperature could lead to cooler European winters – is it little wonder we non-professionals are left to build our level of belief in climate change via a muddle of personal experience, confusion and folk tales? The use of glib phrases such as 'we're due another glaciation right about now' doesn't really help either. I'm deeply interested in the subject of climate change and I think there is serious cause for concern, but the data is open to numerous interpretations.

So what are we left with? (Help: I think I'm turning into Jerry Springer!) For one thing, the term 'since records began' can be about as much use as a chocolate teapot. Each year we get more data (obviously) and so each year the baseline changes. Meteorology and climatology are innately complex anyway, but so far both scientists and our media have comprehensively failed to explain to the public just how little is known and how even very short-term trends are open to abrupt change (as with the notorious 'don't worry' forecast the night of the 1987 Great Storm). But then you have only to look out of the window and compare it to the Met Office website to see we have a very long way to go indeed…

Amazed rats and super squirrels: urban animal adaptations

If I was the gambling sort I might be tempted to bet that the most of the large fauna in my neighbourhood was, like much of London, restricted to very few species: namely feral pigeons, rats, mice and foxes. The most interesting visitor to my garden is, judging by the size, a female common toad - the wondrously named Bufo bufo - which makes an appearance every couple of years to feast on snails and leave a shell midden behind.

After spotting a small flock of Indian-ringnecked Parakeets in our local park, I decided to look at the adaptations wildlife has undergone whilst living in an urban environment. After intermittently researching this topic over a month or so, I was surprised to find the BBC Science News website posting an article along similar lines. Synchronicity? I decided to plough ahead, since the subject is too interesting to abandon and I've got my very own experimental data as well, although it's hardly 'laboratory conditions' material.


It's easy to see why animals are attracted to cities: the ever-present food scraps; the warmer microclimate; and of course plenty of places to use for shelter (my nickname for railway embankments is 'rodent condominiums'). Even the mortar in walls seems to offer smaller birds a mineral supplement (calcium carbonate) and/or mini-gastroliths (A.K.A. stomach grit) judging by the way they peck at them. Then there's also the plentiful sources of fresh water, which in my neighbourhood goes from birdbaths and guttering to streams and reservoirs. Who can blame animals for coming in from the cold? In the case of the London fox they have been arriving since the 1930s, whilst rodents were probably rubbing their paws together in glee as the first cities were being built many millennia ago in the Fertile Crescent.

There seem to be several, obvious behavioural changes that result from urban adaption, particularly when it comes to judging humans. I have found an astonishing lack of wariness in mice, squirrels and foxes, even in daylight, although rats are usually more circumspect. There are an increasing number of stories concerning foxes biting sleeping humans, including adults, even during the day. I was informed by a Clapham resident of how, having chased a noisy fox down the street at night, it then followed him back to his house, only stopping at the garden gate. Clearly there is some understanding of territorial boundaries here, too. This is supported by the behaviour of foxes in my area, which will happily chase cats in the local allotments even during the day, but once the cat emerges onto the street, the fox doesn't follow. Perhaps they have some understanding of connection between cats and humans?

City fauna has become more opportunist, prepared to scavenge meals from the enormous range of foodstuffs available in an urban environment, which around my area seems mostly to consist of fried chicken carcasses, usually still in the box. Even birds of prey such as the Red Kite (no small fry, with up to a one and three-quarter metre wing span) have recently been seen taking food off unwary children. This follows a period of finding food deliberately left out for them, so an association forms between people and food. This then is a two-way connection, with humans helping to generate changes in urban fauna by their own actions. Less time spent foraging means urban animals expend less physical energy, so there may a feedback loop at work here; if surplus energy can aid higher cognition, discrimination of humans and the urban environment increases, and thus even less time is required to source food. A facile conclusion perhaps, but read on for a possible real-life example.

My own experiments on grey squirrels took place about ten years ago, probably at least partially inspired by a television lager advertisement. It started when I found that my bird feeder was being misappropriated by a couple of squirrels. My first idea was to add radial spikes around the bird feeder using garden canes, but the squirrels were more nimble than I had thought, so after adding more and more spikes to create an object reminiscent of the Spanish Inquisition, I had to change tack. I next suspended the bird feeder on the end of a long rod that was too thin for the squirrels to climb on, but they managed to dislodge it at the wall end, causing it to drop to the ground for easy consumption. Rounds one and two to the pesky Sciurus carolinensis. My final design was a combination of spikes on the approach to the rod, the rod itself, then the feeder suspended from a long wire at the end of rod. I went off to work with an air of smug satisfaction that no mere rodent was going to get the better of me, only to find on my return that somehow the squirrels had leapt onto the rod and eaten through the wire!

One point to consider is that the bird food itself was in a transparent perspex tube, which is totally unlike any natural material. So when it comes down to it, are some animals, at least mammals and birds, over-endowed with grey matter when it comes to their usual environment, only utilising more of their potential when faced with artificial materials? Or do the challenges and rewards of being an urban sophisticate cause an increase in neurological activity or actual physiology? The latter gets my vote, if only for the evidence that supports this in human development. After all, the archaeological record suggests that modern humans and our ancestral/cousin species experienced an incredibly slow rate of technological development, with rapid increases only coming after disastrous setbacks such as the population bottleneck around 70,000 years ago, probably following a decade-long volcanic winter.

Experiments using rats in mazes over the past eighty years seem to agree with this thesis. However, there are clearly limits to animals' ability to learn new cognitive skills if they don't have time for repeated interactions, which may explain why most young foxes' first encounter with vehicular traffic is also their last. As for the BBC Science News report I mentioned earlier, research shows that birds with comparatively larger brain to body size ratios are those found to thrive in an urban environment. So it isn't all nature red in tooth and claw after all, but at least on occasion a case of brain over brawn for the city slickers.

Finally, I ought to mention a series of scare stories over the past year about another urban coloniser that seems to be returning after half a century's absence, namely the Cimicidae family of bloodsucking insects. With many of us using weaker laundry detergents at lower water temperatures, some researchers are predicting an imminent global pandemic of these unpleasant critters. So please be careful at night, and don't let the bed bugs bite!