How did we get here?
Before the beginning there was no time. All of what we call space, matter, and energy existed, if we may call it that, as virtual presences capable of phasing in and out of reality so rapidly as to almost escape notice.
In our present epoch such virtual "particles" phase in and out of "existence" so rapidly that their presence does not register with any piece of established reality. But in that place before time and space the entirety of that universe worth of virtuality occupied essentially one place.
Cue the first perceptible moment of time.
As each quantum of virtuality meets its first instant of reality it is perceived by others too cheek by jowl to remain oblivious and locked into reality. In one universe birthing kaboom the Big Bang starts the clock on reality. This appearance and expansion of space has its own momentum, which seems to be increasing over time as the universe expands.
Hundreds of million years later whirlpools of matter coalesced and somewhere a cumulative pressure wave caused pockets of pre-star stuff to collapse from gravity into the first stars.
Stars formed, burned, and died. In the burning nuclear fusion creates all of the elements between hydrogen and iron.
The larger stars were born, burned, and instead of following one of several paths to collapsing down and simply burning out end more violently. When their fuel runs out their large size means that the energy of the collapse produces fusion conditions even more extreme than living stars possess. In a titanic explosion all of the heavier natural elements from iron to uranium are created, and in the next moment flung into intersteller space at ridiculous speeds.
Pass on down a few billion years more and a star born in the legacy of earlier generations begins to burn near the suburbs of the galaxy we call the Milky Way.
Exactly how the planets formed as they did is still a frontier of knowledge. But we know the earliest Earth was quite hot, and all of the cabon available had been taken up primarily with oxygen in gaseous form in an atmosphere of mostly nitrogen and virtually no free oxygen (o2).
More time and at some point life takes hold. Plants take co2 as building material and from the remains of life the first sedimentary rocks form at the bottom of the oceans.
When the Earth was newly formed there was no crust, and the upper and lower mantle were almost liquid from the heat of the fall of a literal planet full of meteorites.
As soon as the planet cooled sufficiently for liquid water carbonic acid formed in the oceans the atmospheric CO2 begainto diminish.
Carbon dioxide is acidic and, along with carbonic acid, has slowly and continuously combined with basic oxides of calcium and magnesium to form our crust of insoluble carbonates like granite removing even more carbon from the atmosphere. The processes that release rock-bound carbon are limited in scope and duration and do not significantly affect the steady drain of CO2 from the atmosphere.
From that point forwards the co2 in the atmosphere has been slowly cycling into stone from which only a tiny fraction can be ever be released again.
All life on Earth are what we call carbod-based lifeforms. What this means is that from the moment the first living thing died and was absorbed into the soil or the bottom of the ocean the Earth's atmospheric CO2 has been falling rapidly on the geologic scale of time.
As Earth cooled ice ages began to appear. The long cycles of freezing and warming, growing and shrinking the biosphere ratcheted more and more CO2 from the atmosphere, where it is available for plants to use as the prime building block of life into sediments and minerals. Despite a large amount of CO2 being re-emitted to the atmosphere yearly by volcanos the unremitting trend has always been down, each epoch averaging less CO2 than the last.
By my horseback calculation two or three more good glaciations without a significant return of carbon to the atmosphere in the form of CO2 and first the plant life, then all other life on Earth will simply cease to exist.
The very best times for life of all kinds were decidedly warmer and had higher CO2 levels than have have occurred since modern man first looked out of caves onto the forests and jungles of Africa.
Warming has been the trend on Earth for well over a hundred years, yet the CO2 emissions of man have only risen above the 'noise' of the CO2 release, (differences in emission from year to year, or decade to decade), by natural processes, namely vulcanism of all sorts, in the last 50 years.
Clearly the politically driven global warming fad lacks solid science at its core.
The older Earth with far higher co2 was, like a greenhouse, a far friendlier place for virtually all green plants than today. Besides the increwsed availability of plant food, co2, Earth was warmer, and as a consequence wetter which vastly increased the arable surface.
Currently we are at co2 levels of .04%, at its lowest in the history of the planet. We are well below the optimum for the biosphere. Despite volcanoes and newly noticed outgassing from rocks the trend has alwas been down. Once natural processes currently operating bring the levels down to .02% photosynthetic, then all life on Earth will end.
Until humans recently started emitting enough co2 to be noticed the only possible future for Earth was this withering.
With the advent of humans a revitalization of the entire biosphere is only as far away as the breaking out of common sense.
[Note] every part of this article was derived from completely uncontested facts taught to science students in physics, geology, and astro physics. This piece has been checked for accuracy by a senior astrophysicist and by the chair of the geology dept at Pomona College: both passed it as correct.