I see two challenges facing the human race.
The current potable water crisis in California is a foreshadowing of the unforeseen consequences of climate change and population explosion. Simple conservation will not be enough. Our planet’s natural water cycle is struggling under the burden humans have placed upon it in their unflinching quest for water. We can survive without oil but we cannot survive without water.
The second is more subtle, but I believe Western society has discarded and forgotten the importance of the softer attributes of what it means to be human. Our quest for progress has pushed aside anything that does not immediately contribute to short term goals and profit. We esteem this pursuit in the media and the “have-nots” are left with two choices. They either resign their drive to succeed and “coast” through the rest of their life, or consciously object and pursue a life at the edge of traditional society through other means.
This is catching up to us as the current trend of press around “Why aren’t millennials <fill in the blank>”. I’m a millennial myself (born in 1982, so at the top end) but see this distinction clearly between my social group.
Society will be forced to repay and repair the rips to our social fabric that have been created. Humans aren’t ready to face this, but I believe I will see the pendulum swing back during my lifetime.