The environmentalists’ boogeyman walks with tiny, uncertain steps. He’s 87 years old, suffers from an arthritic knee and worries about stumbling and falling down. He’s also slowly shrinking — he lost an inch and 24 pounds over the last three years, so now he’s only 5 feet 6 and 120 pounds. But today he’s looking flashy, spicing up his beige suit with a nicely coordinated daffodil-yellow shirt and an amber-hued bow tie.