Weathering frights

Natural human desire and impatience for answers to Big Questions tends to reflect in the media as a black or white approach to issues. On behalf of its public, the media demands instant answers, apologies, resignations. When it does not get them, or (more likely) does not understand the issues, it makes up caricatures, foments indignation, starts witch-hunts. The man murdered his victims because he is ‘pure evil’, being the best-known example. Sometimes this medieval worldview leads to abuse of due process. Myra Hindley was herself a victim of Ian Brady, but her role as his accomplice in the murders of children doomed her to die behind bars, at the whim of the redtop press.

Recently, we appear to be experiencing many more extreme weather events around the world. Is it because of global warming? We don’t know. Do the events in themselves settle what has become a contentious issue? No, if anything they muddy the waters. It could be because interest in climate change has prompted more sensationalisation of statistically normal weather events. A majority of non-scientists do not believe in global warming anyway; not as a man-made phenomenon. Come the next flood or heavy snowfall, and hapless weather experts are paraded on the news; where, as scientists properly should, they display rationality. Just as ‘one swallow doth not a summer make’, so one spectacularly powerful hurricane, one flood of ‘Biblical proportions’ doth not an end to civilization make. But this very caution is seized upon by climate change deniers as proof, if proof were needed, that Mankind is not ringing down the curtain on the planet through driving SUVs to the store. Perhaps the issue is more complicated than most people can be bothered to think?

Currently, there is ‘Biblical’ flooding in northwesternAustralia, and inSri Lanka, where a million people are said to be displaced. Unusually heavy rainfall has triggered landslides inBrazil. Whenever such events occur, whole villages swept away by raging brown torrents, we hear with wearying familiarity the point made by hydrogeologists that human settlement is responsible for exacerbating the situation. Yet people continue to remove the rooted anchor of trees and instead plant houses without foundations on fragile hillsides. We continue to wail and gnash our teeth when poor communities are swept away and drowned in a sea of mud; a perfect example of how Mankind’s denial of simple mechanical principles can lead to environmental disaster. We never learn.

Each of the extreme weather events currently in the news has been described as a once-in-fifty, or a hundred-year event. That puts them well up on the scale of scary weather events in one human lifetime, but on a geological timescale it makes them as common as, well, mud. The Queensland flood of 1893 was worse, they say; 1974’s runs this year’s event pretty close. The winter of 1962/3 beats the recent month of heavy snow and subzero conditions in northern Europe, but is nothing compared with the ‘Little Ice Age’ experienced between 1645 and 1710; while the ‘winter without end’ endured by Laura Ingalls Wilder in 1860 sounds rather worse than the huge precipitations of snow in the northern USA the past two winters when, in 2009/10, for the first time in living memory, the country was snowed-in from coast-to-coast. Going back in time, there was worse; for instance, the hurricane of 1709 that killed 6,000 people in southernBritain. Now that is an unusual weather event; snow in winter isn’t, even when, as this year, it falls inSyria!

Look back over the past two years, however, and we might notice that there have been what do seem to be an unusual number of extreme events. The floods inPakistan, for example, also of ‘Biblical proportions’, to trot out that well-worn cliché, have still not subsided after four months. And the major humanitarian catastrophe of those floods, 20 million displaced people dwarfing the misery ofQueensland, drove down the news bulletins the extreme flooding concurrently in northernIndia,Burma,ColombiaandPeru. Those inundations arrived only a few months after extreme flooding events in centralChina, eastern Europe and in the southern Midwestern states of theUSA, each of which experienced record major river level rises in each of the past two years; and in west Africa. (At the same time, centralRussiawas experiencing its most severe summer heatwave ever recorded.) Drought-stricken Australia is blaming its current misfortunes on a particularly strong ‘La Niña’ effect, being a well-known weather pattern where the ocean currents periodically cool, creating unusually heavy rainfall over the land masses of the eastern Pacific. Even La Niña seems to have gone wrong this year, however, as while it is supposed to have a longer periodicity, there have been two such powerful events in the past four years.

While it is fair to say that none of these once-in-fifty or hundred-year events by itself proves there is a worrying trend developing in global climate, nevertheless, taken together, might they not add-up to perhaps a once-in-five-hundred-years conjunction? And what, then, could a once-in-ten-thousand-years conjunction be like? Pretty ‘Biblical’ I’d guess. Past events have often had a geological explanation; big volcanic eruptions can cool the climate for years. In this case, we have been experiencing for the past three years one of the quietest solar minima ever observed. The known effect of sunspot cycles on global climate is not fully understood, or even fully accepted. There is nothing we can do about them anyway: the earth revolves around the sun, we’re stuck with it. Anomalies in earth’s orbit and inclination do periodically bring us nearer to and further from the sun’s warmth. While it would be madness to deny that climate change is occurring, much of it obviously man-made, there are concurrent geophysical and astrophysical effects that will make climate change either more or less stressful, and need to be factored into our global economic response. Climate science is not a simple choice between good and evil. 

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