Bronzed and deeply lined from decades of life in the desert sun, Mr. Clark is not one to worry about global warming. He suspects that if the planet's climate is getting hotter, it is part of a natural cycle and will probably correct itself. "Experts have been wrong before," he said.
But late last year, Mr. Clark decided to install a $62,000 solar power system because of a new municipal financing program that lent him the money and allows him to pay it back with interest over 20 years as part of his property taxes. In so doing, he joined the vanguard of a social experiment that is blossoming in California and a dozen other states.