Next to Cochise County in Arizona, the town of Willcox may be a rather unassuming place, it's not far from the border with Mexico, but it's home to Howard Buffett, one of the most influential and one of the richest men in the world. Like his famous investor father Warren Buffett, he's a mega philanthropist with millions of dollars to give away to deserving causes. Yet it seems he's not the typical dilettante son of a rich and famous father. He's been honoured for his journalism. He's United Nations ambassador and writes about overcoming global food poverty. Adam Shaw's been to meet him.

I'm in the land of big skies, wide plains and large personalities. The sun is rising on the Arizona morning, and there's a thin layer of mist hanging just above the ground. White, flat clouds are scattered across the sky and a traditional metal skeleton windmill, the kind of scene in countless cowboy movies, provides the distant cluttering sound track to the beginning of this American morning.

I'm already a little late for my appointment with the most important man in the state. But as the sun rises, it lights her land so striking, I just have to stop and look. And within minutes, the sun colours the landscape from shadows to dark green and muted brown farmland. There are a little over 3,000 people living in this town. There's a modest hotel, a few shops and restaurants and a lot of farms.

Howard Buffett, part of one of the world's richest families, is its best-known resident. His owncharitable foundation has $300 million to give away and his wider family's charitable foundation has billions.