If anything gives the world's second richest man sleepless nights at his home in Omaha, Nebraska, it is the certainty that a nuclear holocaust will wipe out the planet. Warren Buffett is convinced the world will end in catastrophe — the only variable in the equation is when the big bang will happen.
The 75-year-old billionaire is fond of explaining that as the population rises, the number of "bad guys" goes up. By all the laws of probability, one of them will eventually get hold of an atom bomb.
"It is the ultimate depressing thing. It will happen, it's inevitable. I don't see any way that it won't happen," he told an American interviewer. "You can't get rid of the knowledge. You can try to control the materials. You'll never get rid of the intent. It is thme ultimate problem of mankind."
An amiable, chatty character with a taste for Cherry Coke and hamburgers, Buffett is known across the US for his folksy homilies.
The annual meeting of his Berkshire Hathaway business empire routinely attracts 20,000 people and has been dubbed the annual "Woodstock of capitalism." He refuses to use computers except to play bridge and dispenses wisdom in annual letters to shareholders. Last year's version quoted Mark Twain, Benjamin Franklin and the baseball legend Hank Greenberg.
Buffett likes to make moneymaking sound simple — he once summed it up as: "Rule number one: never lose money. Rule number two: never forget rule number one."
Yet for all the populist charm, Buffett is a numbers man to the core: his US$44 billion fortune is built on an insurance company and his decisions are based on clinical, rational, quantitative analysis.
His pledge this week of more than US$30 billion to his friend Bill Gates's charitable foundation surprised many of his followers: he had never shown much interest in diseases afflicting developing countries or in funding the education of underprivileged children.
But his biographer, Roger Lowenstein, says it is consistent with his methodical, unsentimental career: "His approach to philanthropy is very similar to his approach to stocks — he wants to find a few ways of giving where he can make a huge difference. He's not into `a little here and a little there.'"
Another author of Buffett books, Andy Kilpatrick, says: "Buffett is the most rational person in the world. He simply saw the Gates Foundation as the most rational way to disburse his fortune."
Gates gave Buffet an 892-page book on the impact of AIDS, TB and malaria. The Sage of Omaha declined to read it — he simply wanted assurance the money would be spent efficiently.
Born in 1930, Buffett is the son of a Nebraska stockbroker who was elected to Congress as a Republican on a political platform described as "to the right of God." Young Warren made his first trade on the stock market aged 11.
As a child, he undertook two paper rounds and topped up his savings by collecting lost golf balls. He put the proceeds towards buying farmland, which he rented out. At Columbia University, he came under the influence of an investment guru, Benjamin Graham, who taught him to look for solid yet out-of-fashion businesses. In 1962, he spotted a Massachusetts textile firm, Berkshire Hathaway, which he bought and milked for funds to pump into other areas — notably insurance.
Berkshire Hathaway's empire extends to furniture, sweet shops and Fruit of the Loom underwear. He has shares in Coca-Cola, Gillette and the Washington Post and a controlling stake in CE Electric, which supplies energy to 3.7m English homes. He shunned Internet stocks, biotechnology and telecoms. The approach has been phenomenally successful: since 1965, the annual increase in his company's value has been 21.5%. A single share in Berkshire Hathaway now costs US$92,000.