The scene, a famous museum of oriental art in San Francisco's Golden Gate Park. The time, the evening of Thursday 3 March 1982. The occasion, a state dinner given by President and Mrs Reagan for Queen Elizabeth and Prince Philip. The weather, atrocious.

The proceedings were delayed, most of the hundred, more, guests are late, what with ploughing through little lakes of rain at the bottom of the city's steep hills, driving through a downpour that felt and looked like a perpetual car wash and, if you came from the coast road, having to take straggling detours from the mud slides that piled up like ramparts on the highway.

By the time the guests were strung out in a reception line, the low buzz of conversation was, in the main, sympathy for the Queen on her first visit to California. She had disembarked from the royal yacht at the southernmost port town of Southern California in a sou'wester. and came ashore in drenching rain and at every stop up the coast, she went through an unending curtain of rain.

She had, with remarkable grace, agreed to be driven up the Santa Inez Mountains to take lunch with the Reagans at their ranch, through roads so deep in mud that the party had to transfer to high-axled four-wheel drive cars and continue a squelching journey that entailed in the end an accident which killed a secret service man.

I remember remarking at the time that someone at the palace who arranges these tours might have checked long ago with, for instance, the Los Angeles and San Francisco chambers of commerce and learned that along that 400-mile stretch of coastline between the two cities, the only months that can guarantee rain are February and March and then only a normal stream. The average rainfall in San Francisco is 19 inches and most of it falls in those months. In the 10 days of the Queen's visit, the city had dumped on it the whole year's supply and, for some reason that the climatologists didn't figure out at the time, the long curtain of rain stretched all the way up the coast into Canada. Our last view of the Queen was going aboard the royal yacht at Vancouver, I believe in a sou'wester.

A high spot of that February evening in the M H de Young museum was, of course, the president's introduction of the Queen and her rising into a piercing spotlight, a radiant lady ablaze with jewels. She came to say – I'm speaking from memory but I'm sure this is pretty accurate – that "I have known since my girlhood that you inherited many traditions from my country but until now I never knew that the weather was one of them", a charming joke that brought on rapturous applause.

Recalling it now I feel myself wincing sharply because what we then thought was an outrageous freak of the California climate we now know was a warning rehearsal or harbinger of a dreaded phenomenon that the climate scientists say will plague most of the world from this late November on and through our winter and spring and Australasia's summer and autumn. A visitation, they say, far more destructive and devastating than the 1982/3 experience of El Niño.

What, asked a visiting English friend of mine, exactly is El Niño? He knows Spanish, so he's even more puzzled to have a phenomenon of climate called the Christ Child, but to respond to the question, what exactly, as they say, is mind-boggling. Put it simply, crudely, first and say it's a stretch of warm water, warmer than usual, that moves east from the central Pacific Ocean every four to seven years. It was so named, long ago, by Peruvian fishermen because it first appeared off their coast on Christmas Eve. It was the sudden strange rising of a current of warm water, 10º above normal, that blocked the cold and – so far as fish are concerned – nutritious water that normally rises from the bottom of the ocean. A weird, almost mystical, procedure but nothing mystical to the Peruvian fishermen. They went broke, the fish either died or moved way south off Chile.

Before this great storm of 1982/3, the various natural disasters that happened at the same time – long droughts in Africa and Australia, massive rains in South America – were taken at the time to be aberrations, oddities, not part of any system. The curious fact that New England and the north-eastern United States had the mildest winter in 25 years was assumed by laymen to be a coincidence and by climatologists to be a puzzle.

Since then, and especially in the past two years, a great amount of research has been done. In general, the random reports from ships at sea have been replaced with many hundreds of buoys that emit constant readings of the changes and extent of water temperatures. Climate scientists have learned now to adjust satellite measurements, to account for volcanic haze, to refine the measurement of the air pollution index.

All this is being done, like earthquake research, in the interest, the hope, of more accurate prediction of the comings and goings of El Niño. Last year Columbia University founded on the west bank of the Hudson here the first research institute for climate prediction. It is headed by a Brazilian, one Antonio Moura, one of the first men to recognise, in so many sporadic and random disasters, a pattern that derived from the Peruvian fishermen's recognition that there was a connection between the warming Pacific waters off their coast and the dead or vanishing fish.

In 1991 Moura told the governor and officials of a state in north-eastern Brazil, that they were about to suffer from El Niño, a new, alarming widening of the warm waters in the Central Pacific. Of course he suffered resistance at the time from scientists and ridicule from laymen who said – and continue to say – how can a band of warm water way off in the Pacific affect the climate of the east coast of South America and New England, let alone droughts in Australia and floods in Western Europe?

Moura told them that the drought in the state of Ceará in 1987 was due to El Niño and that another, longer drought would come in the 1990s. In the first drought the state had lost four-fifths of its corn crop. In 1991, acting on Moura's advice, the state planted drought-resistant crops and in spite of the predicted arrival of a long drought, in this decade that state's farmers have produced five-sixths of their normally bounteous crop.

Dr Moura has surrounded himself up here on the Hudson with many other sorts of experts, who might, who could, help in the evasive business of prophesying the coming of an El Niño – biologists, anthropologists, economists – because the effects of the 1982 El Niño were devastating on the economy of the United States: altogether over $2billion worth of damage from storms and flooding along the California coast, up in the Rocky Mountain towns and way across the country in the coastal cities of the Gulf of Mexico.

By now, as you might guess, several other scientists are busy making ocean atmosphere computer models and sophisticated sonar buoys that not only discover the depth of warm water but also the speed and direction of underwater currents which is, fundamentally, the only way to be able to track where El Niño is flowing and what parts of the earth it will affect adversely.

I threw in adversely there because most of my neighbours here in the north-east couldn't care less about the coming of El Niño, since the prediction for us, again, is the mildest winter since 1982/3 which saved this section of the country over $500million in winter fuel bills.

To define, to refine again, the scope and function of El Niño, I ought first to say what is meant by a band or stretch of warm surface water. The present stretch on which the dire predictions are being based is in width about one-quarter of the earth. Now it's possible to see why El Niño is the second most powerful driver, initiator, cause, of the world's weather, of the comings and goings of rain and drought, the first being the seasons.

Normally the Pacific's warmest waters are in the central Pacific but once every four or seven years warm water moves east, off the coast of South America, while the warmest water stays in the central Pacific and develops, as it's doing now, clusters of thunderstorms. Whenever the El Niño storm centre moves, it alters the jet stream winds that steer storms. It's this violent alteration in the track of winds that upsets normal weather patterns from Africa to New England.

The early drastic effects of the current El Niño are expected to hit California towards the end of next month and I have to say that the scene out there reminds me of the desperate energy of the people along the Ohio and Missouri banks during the huge floods two years ago. Sandbag manufacturers have exhausted their inventories, applications for flood insurance have gone in one company from 100 a week to 2,000, the roofing repair industry has never known such a time.

The warnings, naturally, have been noted as far away as Chicago and will, in the next weeks, noticeably affect the commodities market and – an irony that would be comical if it were not pathetically close to blasphemy – is the appearance in city newspapers of a huge advertisement from a Christian evangelical group that predicts the Second Coming of Christ.

It takes the appearance of the worldwide storms as a sure sign that the Second Coming is imminent. The first appearance of El Niño on a Christmas Eve was God's warning to us all and is why the prophetic storm is called El Niño.


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