No Humans, except for a thousand or so in the hands of "The Dragon". The Dragon, sometimes called the Dragon Lord ruled them like an equal among less educated peers. These one thousand Human beings had the technology of the old world, which was good. You could avoid harming the planet with the use of cleaner technology of lasers, nuclear reactors, etcetera and the newer sciences, of course. With only one thousand Humans left though, the only industry to speak of in Humanity could perhaps be the "Psychology" industry. These were survivalist hard core Humans and soldiers, with a few scientifically minded individuals involved with keeping the last Humans alive. 
The Dragon, however, was quite busy keeping these people educated in numerous ways, both scientific and other wise.