When we think of humanity as a species we should consider it as halfway through its life cycle. Why? Any species that had now disappeared lived half of its cycle in the middle and during that time it got along well without changing much. We have no way of knowing how long our species will last, but at some distant time, it could probably be said that we were in the middle of our physical development in 2020. That’s twenty-twenty hindsight.
Our species is estimated to have hit a population low of about 10,000 humans 70,000 years ago. Our population is now about 7,700,000,000. Just to round it out, because no one can ever know more than approximately, let’s say there were 7,700 humans back at the population crunch. Thus, 7,700,000,000 divided by 7,700 equals 1,000,000 times as many people now as there were then. So, if we were living as they did, then our population would be having a million times more impact on the environment than those people. But most of us are living in a high-technology way and thus we are having a thousand times greater impact than that. A simple multiple makes us having a billion times more impact than they did, and that is unsustainable for very long. Most species went extinct without ever having the kind of impact on the environment that we are presently having.
The big question then becomes how do we as a species behave in such a way that we can live out our species’ life expectancy of 72,000 years? Coal, oil, and air are the one-time-use fossil energy sources that power our civilization, and only air is renewable although it may be the one that fails us first. Our population may drop off the bottom of this chart before it hits ten billion.
World Population history estimates from 70,000 years ago until 2025.
We are willfully not addressing the sustainability problem in a way that will save our species from near extinction.
Probaway - Life Hacks 
Your erroneous assumptions are ignoring proven facts:
Oil is a non renewable resource. Wrong. Oil is renewable made by bacteria deep within the Earth.
We will run out of oil soon. Wrong. We have proven 2000 year reserves.
We are running out of coal. Wrong. Presently we have a two hundred year supply and likely a lot more. America has the most coal and uses it the least of any nation on Earth. There are only 15 coal plants in current operation – China has hundreds.
Global warming will destroy the planet. Wrong. It was predicted over one hundred years ago that an ice age would destroy our planet and Al Gore predicted major calamities by the year 2000. They always get it worng. Ice cores prove that CO2 has been 6000 ppm without any greenhouse effect long before there were any humans and at, the present rate, would take another 2000 years to return to what it once was i.e. green from pole to pole.
Humans are destroying the Earth. Wrong. Nature has already destroyed over 98% of all species before humans ever existed. Humans have barely scratched the surface. If the Earth was an eight foot sphere, humans would presently occupy less than .001 inch of the diameter of the planet and its resources.
Seven billion people are unsustainable for our planet. Wrong. Fuller once estimated that all the people of the Earth could presently live on the Island of Great Britain if it were organized properly. Many nations have now dropped below the replacement birthrates which is becoming a crisis in industrialized nations. The future of mankind is a space based civilization once we escape this gravity well of limited finite resources a.k.a. the Earth.
Our species lifetime is 70,000 years. Wrong. The dinosaurs lasted for hundreds of million of years with brains the size of walnuts. Humans will likely fare much better unless they impose artificial socialistic shortages upon themselves (like energy). We are all still just infants as a species. Only cosmic forces from nature could destroy our species (none of which are under our control).
The meek shall inherit the Earth – trillions of humans shall one day inherit the solar system and the stars beyond. The Earth is merely a womb for our species and not where we will end up. The destiny of the human race transcends the Earth. The birth of humanity will happen when we begin to leave the Earth.
Other than these false assumptions your are almost correct in everything remaining. I agree that sustainability is important, but history has shown that optimism rather than pessimism will prevail. There is no future in doomsday predictions unless you are trying to sell newspapers or get sponsors for the nightly news. Doubtless there will be setbacks, both natural and man made, but humans will adapt and overcome to prevail. It’s all part of human nature. No doubt the universe is unfolding as it should. Have faith in history if not in human nature.