I recommend reading about the Simon-Ehrlich wager of 1980[1] and also about Thomas Malthus[2]. Many very smart people have speculated many times in the past that major population-reduction strategies must be undertaken, and these doomsday predictions in terms of resource consumption have...almost always been wrong. In Paul Ehrlich's case, in 1968 he predicted that "millions of people will starve to death" in the 1970s due to population growth, and mass sterilization was needed to stop it.

The reason why people keep outpacing our own resource constraints decade after decade is that humans, unlike bacteria or any other species you can model population growth after, can modify our own environment, along with the degree of our own resource usage.

Which is all to say, that this statement has been proven demonstrably false more often in the past than it has been proven true: "We will either need unpalatable or forced lifestyle/societal changes or we will inevitably face these unwanted changes when consumption outpaces resources."

[1]https://en.wikipedia.org/wiki/Simon%E2%80%93Ehrlich_wager [2]https://en.wikipedia.org/wiki/Thomas_Robert_Malthus