Will it be a partial or complete mass exinction of human beings during the 6th mass exinction?

Sixth mass extinction is here: US study

I'm thinking that a partial extinction of humans might be likely. Because we have space travel there could already be colonies (secret ones) on other planets from the U.S., China, Russia or Europe already in existence. I have always wondered about all the excess capacity of space shuttles (that looked a lot like the space on a passenger jet (if you added a small fuselage into the bay with seats).

 So, even with the earth completely nuked out of existence there may be already one or more colonies of humans elsewhere done in secret by one or all governments who travel in space presently from earth.

So, my thought is that humans (some humans) likely will find some sort of way to survive through almost anything.

However, by the end of this century because of wars, famines, short potable water supply etc.

I expect no more than 6 billion people to be alive on the planet by 2100 and then 5 or 4 billion by 2200.

Since only 1 billion people is actually sustainable with earth's resources (if we live on the surface and not underground) this makes complete and logical sense.

However, almost anything could actually happen. When one studies history most big events were never completely predictable. It is the secondary chain reactions of events that really blow a person's mind when they study these things.

For example, the government of a large country might collapse. But 10 smaller countries dependent on that largesse of the larger country might collapse also.

So, you might have one large country collapsing and 10 to 20 other countries eventually collapsing because they were all too dependent on the largesse of the larger country in one way or another.

IN this sense a study of history and what often happens might also predict some future events (at least generally speaking).

For example, I fully expected the U.S. government to collapse in the early 1980s. And by itself it likely would have. What I didn't understand then was how other countries were so grateful to the U.S. for helping them survive after World War II ended. So, they loaned the U.S. money so the debacle of the Viet Nam war didn't completely economically collapse our government during the 1980s when combined with the Arab Oil Embargo that caused Gasoline to increase 4 to 10 times and to take away the general prosperity of the average person in the U.S. ever since.

The problem is that everyone grows everything in the U.S. on gasoline or diesel. Everything is transported to people to have food to eat with these fuels. Everything shipped to anyone causes fuel (air or land or sea) to be consumed, so the price of fuels causes the rise or fall of all countries. The cost of energy is everything in the game of survival of developed nations now on earth.

Right now, the U.S. is the largest producer of these fuels on earth. Therefore we have some of the lowest fuel prices on earth which is why we are presently so successful as a nation financially.

However, if oil suddenly stopped flowing here on earth (for any reason at all) within 1 year likely 6 billion people might die. This is the reality that developed nations on earth live with every single day. 

Only people in the poorest regions of earth not dependent upon oil might survive such a calamity or people who are self sufficient in any country regarding power, water, food, land and security.