WHEN Ray Anderson first encountered the concept at an international conference, it took his breath away. It was so smart, so right. It was flexible, practical, beautiful, and made perfect sense. He knew right then that modular soft-surfaced floor coverings (carpet tiles, in other words), could change the world.

Others thought he was round the bend. When he decided to give up his job at Milliken Carpet in LaGrange, Georgia to set up a 15-person carpet company, and was clearing out his desk that February of 1973, two colleagues looked in. “We don't think you can do this,” they told him. He replied, in his languid, ever-courteous southern lilt, “The hell you say.” Fifteen years later his company, renamed Interface, was the biggest carpet-tile maker on the planet.

This also made Mr Anderson a considerable plunderer of the earth. He never thought about that at first. To his mind he was no more a thief of Nature than when, a country boy during the Depression, he had hooked 20-pound channel catfish, now long gone, out of the Chattahoochee River. His business complied with government regulations. His product, too, was much less wasteful than broadloom carpet, since you could easily cut the tiles to run cables underneath, and replace them one by one as they wore out. They were, it was true, almost entirely made of petroleum in some form or another. Some pretty bad stuff was used in the dye and the glue. More than 200 smokestacks blackened the sky to produce them. But boardrooms laid with Interface carpet tiles looked and felt a million dollars.

The turning point, his “mid-course correction”, came in 1994. He was 60, but not yet ready to retire to the mountains or chase a little white ball. Under pressure from customers to produce some sort of environmental strategy for his company, he got a small task-force together. Someone gave him a book, Paul Hawken's “The Ecology of Commerce” to help him prepare his first speech on the subject. Thumbing vaguely through it, he chanced on a chapter called “The Death of Birth”, about the extinction of species. Reading on, he came to a passage about reindeer being wiped out on St Matthew Island in the Bering Sea. Suddenly, the tears were running down his face. A spear-point had jammed into his heart. It was the very same feeling, he said later, as when he had first seen carpet tiles, but orders of magnitude larger. He was to blame for making the world worse. Now he had to make it better.

Interface, he decided, would leave no print on the green-and-blue carpet of the world. By 2020 it would take nothing from the earth that could not be rapidly replenished. It would produce no greenhouse-gas emissions and no waste. That meant using renewables rather than fossil fuel; endeavouring to make carpet tiles out of carbohydrate polymers rather than petroleum; and recycling old-carpet sludge into pellets that could be used as backing.

Some of the technologies Mr Anderson hoped for (and half-envisaged, as a graduate in systems engineering from his much-loved Georgia Tech) had not been invented when he started. Several colleagues thought he had gone round the bend again. He had to bring them along slowly, in his quiet way, until they “got it” by themselves. But by 2007 the company was, he reckoned, about halfway up “Mount Sustainability”. Greenhouse-gas emissions by absolute tonnage were down 92% since 1995, water usage down 75%, and 74,000 tonnes of used carpet had been recovered from landfills. The $400m he was saving each year by making no scrap and no off-quality tiles more than paid for the R&D and the process changes. As much as 25% of the company's new material came from “post-consumer recycling”. And he was loaded with honours and awards as the greenest businessman in America.

Most satisfying of all, sales had increased by two-thirds since his conversion, and profits had doubled. For Mr Anderson always kept his eye on the bottom line. He could be sentimental, ending his many public speeches with an apologetic poem to “Tomorrow's Child” written by an employee after one of his pep talks, but he was only half a dreamer. His company was his child, too. Profits mattered. This made some greens snipe at him, but it also made Walmart send two of its senior people round to his factory in LaGrange to see what he was doing right. As a success, he could powerfully influence others.

The forest floor

He never dreamed of giving up carpet tiles. Their beauty and variety delighted him, just as Nature's did. In his office in LaGrange they were laid out like abstract art on tables, while hanks of yarn hung on the walls. His company introduced Cool Carpet®, which had made no contribution to global warming all along the supply chain, and multicoloured FLOR for the home, “practical and pretty, too”. He was proudest, though, of Entropy®, a carpet-tile design inspired directly by the forest floor. No two tiles were alike: no two sticks, no two leaves. They could be laid and replaced quite randomly, even used in bits, eliminating waste. And when you lay down on them you might almost be in Mr Anderson's 86-acre piece of forest near Atlanta, listening to the sparrows in the long-leaf pines, rejoicing in being a non-harming part of the web of life, like him.