Three weeks ago, the wind was very warm on the Firth of Clyde. We remarked on its untypical heat as it bent the bracken and rhododendrons on the Argyll coast; a fancy, foreign wind coming up from the south where it had been brewed (so the papers said) by a hurricane in the Caribbean. None of us could remember such a warm wind in Scotland before. When you came out of the sea you pretty well immediately stopped shuddering. In the evening, we went to a hotel and asked if we could take our drinks outside to the garden. "You'll need to be quick," the barman said, because by that time the sky had changed from blue to purple-black, with showers tugging down delicate fronds of cloud to the hills in Kintyre.

Then the wind died and it began to rain properly. A couple of hours later the road was like a river on the hills and a pond in the hollows, and the car headlights picked out thousands of frogs that were seizing their chance to explore this unexpected new wetland. We drove farther north through the rain the next day and came across sights that were at first merely exciting: a familiar glen had been suddenly converted into a long loch, with sheep and cattle perched on its freshly created islands; swollen burns and rivers had risen above their bridgeworks and spread earth and rock across the road; patches of sea had turned into milky coffee and uprooted trees drifted helplessly among the foam. Towards the head of Loch Fyne, we began to see fresh brown scars on the steep green hillside, where the earth, which had rested snug and content there for many centuries, had found a life of its own and slipped away.

It was only at Cairndow at the loch's end that we changed from interested spectators to concerned travellers. A landslip had torn through a cottage and spread mud and rubble across the main road to Inveraray and Kintyre. There was no way forward and only a complicated way back (through the private lane of a Highland estate), because other landslides had blocked the roads to Glasgow and Dunoon. The pub was filled with mystified drivers, wondering what to do next. Older people remembered the newspaper pictures of Aberfan, but not even the oldest could remember anything of the sort happening in Argyll before, at least in summer.

We talked about the weather and for how many hours or days the roads would be closed. But we didn't blame ourselves, our prosperity, our cars, our planes, our central heating, our reckless burning of coal and oil; a way of living that you could argue had its origins very close to here, James Watt being a Greenock man and the world's first sea-going steamships coming up the loch well before the battle of Waterloo (and, up there in the early 19th-century stratosphere, the hydro-carbon from the world's first industrial nation starting a process whose effects would remain unknown for almost 200 years).

Nobody said as they debated the immediate future of the A82, "That's it. No more cars for me. How do I join the Green party?" Nobody promised to be a better dweller on and for this Earth. No connections were made between the atmosphere's behaviour and our own. "Global warming" is a phrase that a dozen years ago implied unpleasant things happening to faraway people - a rising sea drowning Pacific atolls and large parts of Bangladesh - while in Britain we imagined vineyards in the Pennines and Mediterranean summers. Few of us realised that climate change would mean "extreme weather" - extreme not just in heat, but in wind and rain and unpredictability.

The consequences are too late to stop but not too late to modify, so that perhaps in 50 or 100 years' time the glaciers and the icecaps could end their retreat and the climate begin to stabilise. Science (most of it) agrees that we need to change the way we live, but we refuse to do it. We like cars, motorways, cheap flights, untaxed aviation fuel. Governments, even when not as wilfully blind to the future as the present American regime, are fearful of their electorates and our consuming desires. In any case, what about the growing economies of India and China? Who will deny their populations' ambition to enjoy the consumables that historically have been mainly the preserve of Europe and North America?

It seems we have made our fate and feel helpless before it. Driving back, I thought of Gandhi and his anti-industrialism, every village its own government, every person to his own spinning-wheel and a diet of goat's milk and vegetables. He had asked people to renounce things, including the popular, material idea of betterment, but even in a country used to the idea of renunciation, where the simple life and the spiritual life are often confused, where the poor with nothing to lose were much more numerous than the rich, it had found few takers. That today's world could embrace a similar movement, restricting human need and desire, hus banding and more equally sharing finite resources, seems close to impossible.

At home, the rain still plinking against the windows, I read more of my proof copy of Jeremy Treglown's excellent biography of VS Pritchett, published in October. I came across a passage about a celebrated symposium published by the Left Review in 1937 called "Authors Take Sides on the Spanish War". Many writers, most on the Republican side, contributed (including WH Auden, Samuel Beckett, Aldous Huxley and Arthur Koestler) and the idea has been reprised many times. The Guardian sometimes does it, most recently on Iraq. What side writers privately take in public arguments is always interesting to know and even, improbably and very occasionally, influential.

But wars in other countries are easy stuff, involving personal opinion (easy to give) rather than a change in personal behaviour (harder to make). And yet climate change is, we are told, a far bigger threat to the world's civilised future than terrorism (though it will undoubtedly promote various kinds of armed struggle in itself).

Which writers would stand up and be counted on global warming if the symposium were entitled "Authors Take Sides on Their Volvo, Their Second Home, Their Easyjet Flights to Tuscany, and Their Weekly Drive to Waitrose?" I hope not to be asked.

· Ian Jack is editor of Granta magazine