On what killed the dinosaurs, ... and you don't look so good yourself.
With apologies to Harlan Ellison, I shall begin this post by stating that what follows is very much speculation. The future is not set in stone.
Collisons can be very scary, and so are those moments just prior to the crunch of metal, moments when tires squeal, brakes burn and stomachs lurch. A collision is coming, and I just might know when.
Water will become a bigger deal than oil sooner rather than later. Already India and China are eyeing the glaciers of the Tibetan Plateau as their farmers deplete ground water at ever increasing rates. Those glaciers, and others around the world are melting faster than aniticipated. Water is life and with over 2 billion people between them, China and India will both want life for their people. Water is also disappearing in the USA. The Oglalla aquifer, waterer of our nation's breadbasket, is being drained at an alarming rate.
Global warming will exacerbate the water shortages and contribute to death of our planet's oceans via higher temperatures and acidification. Methane released from underneath melting permafrost, and the killing of the boreal forests will increase the rate of GW.
Peak oil may well have already occurred. We have the ability to put oil and coal behind us, to relegate them to the histories of the previous century; imagine what 700 billion dollars could have done to end our addiction to fossil fuels. But that won't happen; you can bet that the oil industry will linger far longer than it should. It's greasy, skeletal hands will reach from its grave to gather as much to itself as it can. Greed will guarantee that. Greed and the gullibility of people who will look backwards, averse to an increasingly dark future, to a past that wasn't as good as they remember.
Our national debt per capita will excede our GDP per capita so the USA will not be the world's problem fixer. Eventually we will have to decide whether or not we care for our people more than our weapons. Each nation will look to it's own interests more and more; they will not be able to afford anything more.
Even now Russia burns while Pakistan is under water. Failed states already exist. The times, they are a changin'. The above articles mention events that may transpire in the years to come, and in them, one year seems to occur repeatedly either directly or through averaging. That year is 2030, the year of the collision, when the hopes and dreams of 8.3 billion humans run head on into the immovable, desolate and uncaring Earth.
So what killed the dinosaurs? They couldn't adapt to an environment that was changing rapidly. They could not learn to survive in a new climate. And we don't look so good ourselves.