According to NASA, 2015 was the hottest ever in recorded history for the entire planet Earth.

ISIS now controlling oil from northern Syria.

Businesses and companies around the world, but mainly the US, continues to buy oil, thus supporting the ISIS financially not to mention that the initial firepower ISIS now has was left there for the taking after Bush left. He never took his weapons with him!

People keep burning oil and destroying the Earth's climate while at the same time giving ISIS more power to cause even more destruction.

Huge companies keep trying to cover up the global warming by buying off biased news agencies and telling the public that the warming of Earth is nothing but a huge SCAM. Why? Because research has shown that if every company in the world went "green" they would be very far away from any profitable investments, that's why. There's no money in the green! How's that for irony?

The situation with Russia and ISIS is going to escalate exponentially very soon now, after the Russian plane was shot down.

tl;dr People keep trying to destroy the planet like there's no tomorrow.

Reduce the human population to 250million with none having genetic predispositions to congenital diseases or other genetic faults such as eye sight deformation, weak joints, etc.
None would have an IQ less than 130. And they would have an even ethnic mix depending on aforementioned genetic quality.

From there on maybe we'd actually have a chance to preserve this world and grow as a species.