UfOs have always been amongst us. Why? Because we are biologically related to them.

They are from the Past, present and future. However, we usually don't think this way. However, to go Great Distances through Space you also need to travel time to make this efficient too. And this Time Travel is how they help us the most as relatives.

Most of them don't want to go extinct. Only UFO Criminals do. And for the most part they are policed by the Galaxy.

So, from their point of view it is trying to prevent the extinction of their relatives (near or more distant) here on earth.

So, they bring technology (like the computer or other device you are reading this on) from stuff reverse engineered from the Roswell Crash.

Also, in 1947 you notice Transistors were suddenly invented after that crash too and didn't exist really before this in such a small and usable form and only existed really in vacuum tubes before this. And soon after this we had little hand held battery operated radios. (at 8 or 10 years old) I had one I think it was a Zenith Brand which could fit in the palm of my hand in 1958 when I was 10. 

So, how will they keep us alive?

Their goal (because of the nature of the ecology of earth) is to reduce our numbers down to around 1 billion people because otherwise we will all go extinct if we continue to try to live on the surface of earth being this many people.

We reached 1 billion people in the early 1800s if you research this on the Internet. 

However, that is the most people that is sustainable here on earth for thousands of years.

So, obviously 8 billion people (at least on the surface of earth) is not sustainable simply because you cannot feed this many people while living on the surface of the earth. Also, burning things like humans do for 8 billion people will raise the temperatures too much and cause a mass die off of humans.

(WHICH IS ALREADY HAPPENING THROUGH GLOBAL CLIMATE CHANGES AT RANDOM WORLDWIDE).

So, the point is humans are likely going to be reduced down now mostly through self caused Global Climate changes more than anything else.

And the biggest thing to prepare for is not flooding or droughts because people one way or another can survive flooding (by getting away from the floods) and Droughts (by moving away from the droughts).

But, the winds coming this century  through hurricanes, tornadoes and just the heating of the oceans by the sun through global climate changes won't be survivable unless you are living underground simply because everything wood is going to eventually blow away, houses made of wood, trees made of wood and most plants are just going to blow away.

And people are NOT Prepared for this (at least right now). But, any that survive this century will slowly but surely have to prepare for these winds and start growing food underground to avoid these winds so they can eat.

So, those that survive this century will learn to grow their food underground from solar grow lights and solar water pumps in order to survive worldwide.

This is the primary reason 7 billion people less will be alive on the surface of the earth (at least) by 2100 AD.