His book [The Ultimate Resource]?, later reissued as [The Ultimate Resource 2]?, is a massive assault on the conventional wisdom of population growth and resource consumption. In it, Simon challenged the neo-Malthusian notion that an increase in population has negative economic consequences, that population is a drain on natural resources, and that we stand at risk of running out of resources through over-consumption.
Julian Simon and Paul Ehrlich entered into a famous wager, betting on a mutually agreed upon metric of resource scarcity.
Many of the writings of Julian Simon are available online at: http://www.inform.umd.edu/EdRes/Colleges/BMGT/.Faculty/JSimon/