High Tide: How Climate Crisis is Engulfing Our Planet

As it happens, such evidence is indeed available for the UK. To find out more, I went to visit the climatologist Dr Tim Osborn at the Climatic Research Unit (CRU), part of the University of East Anglia. It was almost two years to the day after the start of the autumn 2000 disaster, and there was a hint of winter in the air as the London train sped through the Essex town of Colchester, past the River Stour saltmarshes and on through the flat Norfolk fenlands to Norwich.

As so often, Osborn confounded my expectations. No white lab coat for him: instead, a youngish, fair-haired man in shorts, trainers and a red golfing T-shirt was leaning over the balcony three floors above as I arrived at the round, glass-fronted CRU building.

‘Hello! Come on up,’ he shouted as I climbed the stairs. His room was strewn with back copies of the International Journal of Climatology and meteorology books, as well as sheafs of paper – many covered with impenetrable algebraic scribbles.

‘Sorry about the mess,’ he said as I sat down on a free chair. Then he swivelled his own chair round to face the computer screen. ‘Now, have a look at this.’

Osborn has spent years analysing nearly half a century of rainfall statistics. From a damp day in 1960s Blackpool to a torrential summer downpour in 1990s Devon, all these records were fed into his number-crunching computer. When spat out the other end into a series of graphs, these statistics – rather than just showing the usual random vagaries of the British weather – showed that something very unusual was going on. In fact the trend was so clear that even Osborn himself was ‘surprised’ by what it revealed.

What Osborn discovered was that over recent decades heavy winter downpours have indeed increased dramatically. ‘Over the period from the 1960s to the mid-1990s there was a doubling of the amount of rain that came in the “heavy category” in winter,’ he explained. ‘So in the 1960s something like seven or eight per cent of each winter’s rainfall came from what we call the “heavy” events, whilst by the mid-1990s that had increased to about fifteen per cent.’

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With more rain falling in a short time, river systems were unable to cope – and floods were the inevitable result. What’s more, this heavier winter rainfall was directly related to rising atmospheric temperatures.

Straightforward atmospheric physics suggests this could be the global warming ‘smoking gun’. The relationship between temperature and the air’s capacity to hold water vapour is not linear – in fact the air can hold proportionally more water as temperature rises.

(#litres_trial_promo) So in a given ‘precipitation event’, whether it is snow, hail or rain, more water is available to fall out of the sky over the same short period of time.

This is exactly what seems to be happening in Britain: as a result of global warming, more warm, saturated air rushes in from the Atlantic, causing stronger storms and heavier rainfall. As a result, the probability of heavy rainfall has doubled over the last thirty-five to forty years in southeast England, according to observations and analysis conducted by Osborn and his CRU colleague Mike Hulme.

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These aren’t one-off downpours, either. The frequency of prolonged five-day heavy rainfall events has also been increasing. In Scotland floods have been getting far more frequent over the last few decades, whilst in England and Wales there have been four major floods in the last twelve winters: 1989/90, 1993/94, 1994/95 and, of course, 2000/01.

(#litres_trial_promo) The match for 2000 isn’t perfect because the worst flooding came during the autumn – but the floods also lasted right through until January, just as the trend would suggest.

Osborn’s work also coincides with evidence from other parts of the world. Study after study has come to the same conclusion: that throughout Earth’s mid-latitudes, rainfall is getting heavier and more destructive. There has been a steadily increasing rainfall trend in the United States through the twentieth century, and much of that increase has come in the heaviest downpours. A number of catastrophic floods in recent years – most notably the Mississippi floods of 1993, the New England floods of 1997 and the winter floods of 1997 in the Pacific northwest and California – seem to show the shape of things to come.

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Scientists have reached a similar conclusion in Europe,

(#litres_trial_promo) whilst in Australia rainfall totals are also rising steadily.

(#litres_trial_promo) This might seem to be a good thing in a continent often afflicted by drought – but again, much of the increase has come in the heaviest deluges, which are less likely to soak productively into farmland, and more likely to run quickly off the land in destructive torrents, taking the fertile topsoil with them.

One study looking specifically at large river basins – such as the Yangtze in China and the Danube in Europe – confirms what many people have long suspected: that big floods are indeed getting more frequent. In fact, sixteen of twenty-one ‘great floods’ during the twentieth century have occurred since 1953, and in the planetary mid-latitudes seven out of eight have also occurred in the second half of the century.

(#litres_trial_promo) UK-based researchers have also identified a near-global trend towards heavier rain and floods.

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In the most comprehensive survey of all, the Intergovernmental Panel on Climate Change (IPCC) confirmed that rainfall was getting heavier and more extreme in the United States, Canada, Switzerland, Japan, the UK, Norway, South Africa, northeast Brazil and the former USSR.

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This hasn’t affected everywhere: some places have got drier, such as the Sahel in Africa and northern China. But almost the whole of the Earth’s mid-latitudes has been affected, and as Osborn told me, ‘if there’s something coherent going on at all the mid-latitudes, then there must be something virtually global scale driving it’. Computer models of global warming have long illustrated this effect, and now it seems to be showing up in the real world, just as many scientists – including Osborn himself – have long predicted.

MONMOUTH, FEBRUARY 2002

Just under 10,000 homes were flooded in Britain during the 2000 event. Some were hit two or three times, and a few left completely uninhabitable. Transport and power services were disrupted, and the cost of flood-related damage eventually totalled around £1 billion, according to the government’s Environment Agency.

(#litres_trial_promo) Everybody breathed a sigh of relief when it was finally over, but only one year and three months later – in the first week of February 2002 – the floods were back.

This time one of the worst-hit places was Monmouth, a historic town just over the Welsh border at the confluence of the rivers Monnow and Wye. On 4 February ‘severe flood warnings’ were issued for both rivers, schools were closed and residents in low-lying areas began to move themselves upstairs. Twenty families were evacuated from mobile homes when the Wye burst its banks, and three streets were completely submerged.

Judging from the news Monmouth sounded well worth a visit. This meant hiring a car, but I was ready to leave by mid-morning, heading towards Cheltenham on the old A40. The River Thames was pretty high, and when the road crossed some small rivers on the way over the Cotswold hills, I could see that each was swollen, its banks only identifiable by lines of willow trees standing in the brown water.

Just outside Gloucester was the first sign of large-scale flooding – a huge new lake stretched almost as far as the eye could see. Trees, telegraph poles and even an electricity substation were surrounded by water, and a couple of swans paddled by.

I drove on. The sky was darkening again with ominous clouds as I neared Wales, and soon a heavy shower sent torrents of new water coursing down off the hillsides.

About ten miles outside Monmouth I spotted a ‘Road Closed’ sign and drove round it to investigate. I was deep in the Forest of Dean, and the small road led down a steep wooded valley towards the River Wye. On the river itself was a small village, little more than a hamlet, called Lower Lydbrook.

Lower Lydbrook looked like it had been doused entirely in mud. Mud was everywhere: across the road, the pavements, people’s drives and lawns. The whole area had clearly been awash with very dirty floodwater only a few hours beforehand. Outside the Courtfield Arms a man was sweeping the sticky brown mess off the car park. I slithered up to him and asked whether he felt the flooding was getting worse.

His answer was surprising. In the past the floods had come once every three or four years. Now it was two or three times in a single year. And the latest inundation was easily the worst for three decades.

On the other side of the road was a restaurant called the Garden Café. All the gravel in its neat drive was coated with the same brown layer, as was a car parked outside. I followed some fresh footprints round to a side door. It was swinging open, and I peered into the gloom inside. Not surprisingly the place was a mess: fridges were stacked up on tables and wet rugs were hanging from the beams. There was a pervasive damp musty smell, and a clear high-water line about a metre up the walls.

The owner was happy to take a break from cleaning up, and introduced himself. ‘Paul Hayes. Owner and chef of the Garden Café.’ He looked around at the disastrous mess and added: ‘Currently on holiday.’

Hayes was certain that the flooding had got worse in recent years. It wasn’t necessarily that more rain fell overall – but rather than being averaged out over a month, the whole lot simply fell in one night.

‘We don’t have a winter any more, we have a wet season. It’s like tropical rainstorms here. And because it’s a hilly area this translates into flash floods. The river rose six metres from its level last week. It came in here at four on Sunday morning, and within another two hours reached a metre up the wall. It never used to flood in the house, but that’s three years in a row we’ve been flooded now.’

As a result, his business was wrecked. All the fridges were ruined, he was losing customers every day the restaurant remained closed, and all his stock would have to be thrown away. Nor was this the first time: during the winter of 2000 – when the building had been flooded on three separate occasions in October, December and January – he had only managed to open for twelve days throughout the whole four-month period. And with the whole property now virtually uninsurable, no buyer would even look at it.

Hayes had a knowing, worldly manner, but I could tell that even he had been thrown by the latest deluge. ‘It came so suddenly,’ he said, almost perplexed. ‘I knew it was going to flood, even though there was no flood warning. And if it rains in the next week it’ll flood again – all that water’s got nowhere to go.’

In Monmouth itself the floodwaters had only just begun to recede. Most of the town was unaffected – the Romans had sensibly founded it on a hill, but developments in more recent centuries have extended the town right along the river. Built at the confluence of two rivers, and not far from the tidal estuary, the area has always been prone to flooding – the one reliable crossing point has been called Dry Bridge Street since Norman times.

When I arrived, though, Dry Bridge Street was half underwater.

Children were splashing around and riding their bikes through it, whilst dog-walkers in wellington boots waded through to a nearby park. Sandbags were stacked in front of every front door. Opposite the bridge itself, the Green Dragon pub had narrowly missed inundation just hours earlier. A hundred yards away, the Britannia Inn had not been so lucky, and water was still being pumped out of it into the road.

I knocked on the door and it was opened by a young woman with short brown hair.

‘We’re closed because of the floods,’ she began, looking at me as if I were stupid. But when I explained what I wanted, she invited me inside.

Several regulars were sitting on benches reading newspapers in the gloomy half-light. A couple of others were helping sweep mud off the stone floor. Everyone agreed that the flooding was getting worse.

‘This place is rotting,’ complained the landlady. ‘There is constant damp from the rain and sewage.’ She poked disapprovingly at some blistered paint on the lower walls. ‘It just keeps getting flooded. In the past it didn’t seem as often – now it’s twice a year. It’s just constantly, all the time. It’s hard enough to make a living in this trade as it is, without all this happening.’

‘Thirty years ago you knew what the seasons were,’ one of the regulars added, leaning on his broom. ‘Now you don’t know. It’s got to be to do with the way the weather changes – the rainfall is unbelievable.’

I drove out of Monmouth and into Wales, the first mountains rising up in the distance. It was raining again, and just before Crickhowell flood warnings appeared by the side of the road. A small house next to a layby was completely surrounded, the water so deep in places that only the tops of the roadsigns stood out. I reached Machynlleth and my old friend Helena’s house, on the west coast of Wales, long after dark, and lay awake listening to the rain hammering on the roof long into the night.