Ashok Khosla does not fit the stereotype of the Indian ecologist-the jholawala with a handwoven bag, sweaty armpits, commuting by bus or bullock cart. He drives around in a white Maruti Esteem making no effort to replace the petrol it uses as fuel with the more ecologically correct CNG. Neither is he apologetic about living in Delhi's upmarket Vasant Vihar in a house that his father built saying, "It seemed silly to waste it and live in a slum."

MR APPROPRIATE: Khosla brought relevant technology to villages

His voice is civil, refined, accented. More suited to the hallowed halls of academia than in the dustbowls of India's hinterland where he does much of his acclaimed work. The prefix Dr is for a PhD in experimental physics from Harvard University and not, please note, in environmental sciences. He spent his formative years "theorising on the innards of the atom" far removed from the hunger pangs of India's poor. The pinstripe suits he dons while globe-trotting for the cause accentuates the contradictions. He does wear kurta-pyjamas to work in India but critics carp that they are of designer class. He is clear that the clothes he wears is not to make a statement but because they are "appropriate while dealing with my clients, the peasants".

The word "appropriate" is something Khosla has devoted most of the 62 years of his life exploring and defining with a rare perseverance. It has seen him being acknowledged as not just one of the world's prominent environmental thinkers of our times but also a consummate doer. Last month Khosla entered the ecologists' hall of fame when he was awarded UNEP's prestigious Sasakawa Environment Prize for 2002 worth $200,000 (Rs 96 lakh). Lord Clinton Davis, chairman of the award's selection committee, says, "His work on environment has had a large ripple effect not only in India but around the world."

Khosla's approach is refreshingly different. Early enough he decided that caring for the environment did not mean shouting. Or saying no to development projects. He believes that a "large part of activism is an ego trip". He had a cause but he wasn't going to be a rebel to achieve his ends. Even if it meant being labelled by detractors as Mr Establishment. He acknowledges that movements such as the one against damming the Narmada led by Medha Patkar have their role to play. But it was not going to be his way. "I would be satisfied if I created jobs and empowered people rather than stopping dams from being built," he says.

The enterprise route evolved when at Harvard he began to feel the disconnect between his pursuit of blue-sky research and the reality in India. He agonised over why science couldn't come up with appropriate technology to make the lives of poor people better. It drove him to audit courses at Harvard on economic development and business management to understand, what he terms, the nexus between people, the resources and the environment.

Along with famed oceanographer Roger Revelle he then set up a course on nature sciences at Harvard and even brought out a book titled The Survival Equation. Among their students was Al Gore, the former US vice-president who said it deeply influenced his thinking on the subject. By then Khosla says more than being a scientist, his driving ambition was " to be Indian". As corny as that may sound, only someone who has lived outside India from age seven can comprehend the need to belong. Coming back to India, says Khosla, was "non-negotiable".

When Khosla came back in 1971 for a decade he had successful stints as environment adviser to the Union government and later to the UNEP. But it bothered him that catchphrases such as "sustainable development" and "appropriate technologies" had become hollow and meaningless. He believed that "if you have a good idea then you are responsible for implementing it". So in 1983 he chucked up everything and set up Development Alternatives, an NGO, from his house. It was primarily to see if putting his shoulder to the boulder of apathy could make a difference. He was clear that anything he did to help India's villages had to have the "triple bottom line imperatives-financial, social and environmental sustainability".

As in physics, Khosla chose to work with atomic size projects that could produce a chain reaction of development. When he found that roofing in most villages was a problem he put together a research project to evolve a tough and durable roof tile made from local material by a process that village masons could understand. Each mini tile manufacturing unit provided jobs for five people apart from workers needed to lay them. It fitted well with Khosla's philosophy: It was relevant, renewable, cheap, easily replicable, gave users a sense of ownership and made them independent.

Over the years Khosla has evolved 15 such environmentally sound and commercially viable technologies that have generated more than three lakh jobs across India. They include innovative check dams that recharge degraded land and decentralised power units that villages could set up using agro-waste and wild weeds as gassifiers to drive the generators. R.K. Pachauri, director-general, Tata Energy Research Institute, says, "Khosla's success is his ability to franchise technology in rural areas." Nalni Jayal, a former Union Environment Ministry official, adds, "He has taken ecological precepts and translated them into reality at the grassroots."

Khosla's latest venture is an Internet portal to spread his work. He believes telecom technology can't be easily hijacked by the rich and will become a powerful tool to decentralise development. For him, empowering the poor guarantees environmental security. It is why Khosla is often regarded as "a Gandhian in a suit". The description is appropriate.