Carrying capacity is the concept of the population size that a habitat might sustain. It is merely an abstract idea that fails to account for environmental dynamics. Given stable conditions, animal populations tend to grow toward carrying capacity. This certainly has been true of humans, with technology as a multiplier of what carrying capacity would be otherwise.
Technology has been a double-edged sword: affording burgeoning populations immediately while undercutting carrying capacity from environmentally unsustainable practices. This tendency has been apparent from prehistoric times, as hominins harvested all a locale had to give until it was exhausted, and then moved on.
With industrial-strength technologies and a diaspora resembling microbial infection on a global scale, the human toll on the planet provoked the instant mass extinction event, of which we now witness the early throes.
Not only human population density, but the growth of the human population, is still having an effect on extinction threats to other species. ~ American anthropologist Jeffrey McKee