Earth's history has been gathered from year upon year of studying sediment & ice and supported by scientific method.  Each time a new moment in time is found, it is placed on a timeline which gives us a rough estimate of what our planet's history looked like. Time and time again, extinction events have been recognized.

We are not even a speck in the timeline right now and at any point and time a space rock the size of Texas can smash into the Earth at unimaginable speed and wipe out life on this planet.   Living underground can only get us so far, and unless we have fully functional cities underground for all to live, most of us will not survive such a thing. Who/what would survive? 

Let's imagine humans survive.  Let's imagine a certain number of individuals made it past an ELE (Extinction Level Event).  Who would those people be?  Would they be willing to understand the chance involved in just having the ability to live on this planet?  Would they learn from the mistakes of the past?  

What are we going to leave behind on the Geologic Time Scale?   Will we leave behind rich soils, clean fresh water, lots and lots of life?  If a big space rock smashed down on the planet right this minute, will our time in this scale see lots of life all stop abruptly?  Sure it would.  But would we not also see life diminishing over time, increase in deserts, changes in salinity coupled with increased carbon dioxide in the our oceans and highly volatile groundwater?  Sure we would.  Think those landfills will break down and create a soil mixture not found in our geologic time scale?  Sure they will. Maybe we can get a jump start on the future of the Geologic Time Scale by adding a layer of sediment rich in broken down plastics, debris and toxic chemicals.  

It is not necessary to point the finger at who or what created this because the truth of the matter is each of us, in one way or another have contributed (willingly or unwillingly) to the planet's current state.  The blame game just does not apply.  Instead, we have to learn from those past and present mistakes being compounded on a daily basis.  Truth is, if we pay attention to what has been happening, we see preventable disaster just about everywhere we look.  And while our hearts are in the right place, our slow call to action leaves an era to be desired.

References/further reading: