Tim Lott: Like it or not, we've just lived through a week we won't forget

Empty skies and Cleggmania were bolts from the blue. What do they presage?

The distant sky was soiled with vast pillars of ash, and yet here above Britain it was uniquely empty and silent. Beneath those misleadingly perfect blue skies, there was an odd, almost surreal flickering of possibility for the nation with the emergence of Nick Clegg – a saviour, to some, who will give balm to ancient wounds.

In his TV debates, TV Clegg has echoed the Obama campaign, daring us to hope. And sure enough there was something hopeful about last week, or at least, cheerful. The extended holiday for many, the change of season, the absence of polluting behemoths above our heads.

But the week was also eerie – as if somehow events were trying to tell us something, or perhaps, warn us of something. For there are periods that we live through, as the days flicker randomly past, that seem earmarked for future nostalgia or flagged up for future significance.

Artists grope to describe this feeling. Fay Weldon wrote that the vast billowing cloud emerging from the Icelandic volcano was "an outer manifestation of our inner fears, our boiling rage". Certainly the TV pictures of beautiful yet threatening towers of smoke trapped in the frame of a celestial blue backdrop held a poetic resonance. Add the drumbeat of an oddly insistent series of natural catastrophes that seem have taken place since the Asian tsunami of Christmas 2004 and the sense of resonance intensifies.

What does it all "mean"? Nothing, probably. The feeling that we're at a poised, empty moment in history waiting to be filled with events of titanic significance is liable to be illusory. The human mind compulsively creates patterns, seeks meaning, and makes connections where there is none.

Yet one doesn't have to subscribe to the loopy notion that the universe is "talking to us" to recognise that there are moments in history that our imaginations deem to be harbingers. Sometimes we see those symbolic moments only in retrospect, sometimes we identify them at the time, but they crop up every now and again and become etched deeply on our collective imaginations.

The most obvious example is the +summer of 1914. That "perfect summer" came to represent the end of innocence, the collapse of the ancien régime, the last days of Edwardian glory – the closure of a certain myth of what it was to be British. Whether in the poems of Rupert Brooke, the books of EM Forster and Erskine Childers, or the films of Merchant Ivory, that summer represents the imagined Edwardian summer, of peace, prosperity and stable social hierarchy. In truth, it was just weather that happened to be followed by war – but we have imbued it ever since with a powerful meaning. That summer is the template of what you might call "idyllic harbinger" – that is to say, a brief moment of beauty or bliss that marks the passage into something darker.

More common than the "idyllic harbinger" is the "catastrophic harbinger". This is a disaster, or series of disasters, that seem to offer us signposts to oncoming crises that will be greater still. One example is the burning down of the Crystal Palace in 1936, a glittering symbol of the British empire, presaging the fall of the Empire itself in the aftermath of the Second World War, economic failure and global independence movements. "This is the end," said Churchill, in tears, when he heard the news.

Another is the hurricane of October 1987, which heralded a massive stock exchange collapse, the bomb at Enniskillen, the Hungerford massacre, the Zebrugge ferry disaster and the fatal fire at King's Cross. The Thatcher "economic miracle" suddenly ended. Property crashed, unemployment spiked and a serious depression had begun. All coincidental of course – but the imagination does not think so.

Some harbingers are writ so large no one can mistake them. You didn't need a crystal ball to interpret the events of 11 September 2001, taking place shortly after the election of a hardline Republican president, as harbinger of a more volatile and dangerous era in global politics. But the "clear blue sky" out of which the aircraft swooped to take down their prey has now come to represent the idea of a sylvan time of relative peace and prosperity. Not quite an Edwardian summer, but a beautiful New York autumn morning. The pattern is familiar – the idyll, and then the catastrophe.

Any historian would know that such events had intrinsic meaning and countless large-scale consequences But it is the symbolism rather than the simple cause-and-effect that fascinates – the dark poetry of the towers' slow collapse, the way, once again, the universe seemed to try and "tell us something" – perhaps the end of a certain world order, of American hegemony, even capitalism itself.

These symbols – the long, hot summer, the burning palace, the whirling hurricane, the falling towers, the clear calm September sky punctured by lonely, swooping, malevolent steel birds – is a separate category of events from non-mythic events, however significant, such as the collapse of Lehman Brothers in 2008 and ensuing near-destruction of the global economic order.

Such events are anything but prosaic – but there was no image left behind to exemplify that bonfire of vanities. The event, or process, held nothing lyrical in it. It just happened – and more things happened after in consequence. The literalist will say that this is always so. Things just happen.

I, too, am a literalist – at least in my head. I also know that a lot of these imagined "turning points" – most notable the arrival of the millennium and the predictions of the global catastrophe that would follow – are empty falsehoods. But the imaginative part of my mind refuses to let it be so. And I'm not always sure the part of my brain that looks for patterns and messages is quite as senseless as I sometimes suppose it to be.

Last week I watched BBC4's Beautiful Minds, which focused on James Lovelock, the scientist who formulated the Gaia theory. Lovelock was ridiculed in the 1970s when he first suggested that the earth, its climate and the organisms that lived on it were part of a connected system that acted as a whole to preserve itself.

Now his views have become part of the accepted mindset of scientific discourse. The philosopher John Gray compared his genius with that of Darwin. The earth is indeed, it appears, a self-regulating entity. This revolutionary discovery bears on the argument of "symbolic moments" in human history in two ways – one of them exciting, the other depressing.

First, it suggests a hidden hand genuinely does operate in the unfolding of world events – something greater than the force of unalloyed randomness, or mankind and its collective reason and intelligence. This is the exciting part – that we are not kings of creation after all, but organisms that form part of a larger system operating to its own rules and "intentions".

Second, and more depressingly, it seems that the system has had enough of mankind. Lovelock was quite flat about his conclusions after a lifetime of study. However much we cut carbon emissions, he said, nothing could stop civilisation collapsing in anything from as little as 10 years ("10 to 100" was the phrase he used). Only 15 per cent of us, he suggested, would survive by the end of the century.

It's a bleak vision, but one cannot dismiss a mind as powerful as Lovelock's. Add to this the dramatic straitening of our economic circumstances that will follow the election of whichever government we choose, the imminent arming of Iran with nuclear weapons and what appear to be wars without end in the Middle East, it is possible that one day we will look back on this week in April 2010 as a bright, strange week that held in it the seeds not of hope, but a warning.

To my mind, there is an almost creepy prescience in WH Auden's great poem, "September 1939", which could as easily be titled "April 2010".

At the beginning of the poem, Auden sits in "a dive", feeling

Uncertain and afraid

As the clever hopes expire

Of a low dishonest decade:

Waves of anger and fear

Circulate over the bright

And darkened lands of the earth,

He goes on to suggest that we are incapable of ceasing our mad rushing around:

The lights must never go out

The music must always play

unless we see ourselves as we really are:

Lost in a haunted wood

Children afraid of the night

Who have never been happy or good.

Perhaps the events this month in our "bright and darkened lands" are, then, harbingers. Perhaps they mean nothing. Or perhaps the auspicious message written in the clear skies was that this is, as Nick Clegg wants us to believe, a time for hope.

Whatever the case, I imagine, somehow, that we will look back and remember April 2010. I hope it will be with nostalgic warmth – but "children" that we are, with our greed, our wars and suicidal project to destroy the planet, I suspect that it is more likely to be with bitter longing.