He envisions people living in big glass-carbon fiber domes on the surface, with additional areas mined out below the surface by robots for "industrial" uses.
He said he had intended to announce his retirement last year but chose to stay on while BHP dealt with the aftermath of the Samarco mine disaster in Brazil.
BHP is not the first major player to flag green shoots in the mining industry. Caterpillar, the world's largest heavy machinery maker, said the same last month.