I know it's all P.C. to blame global warming on human industry and all, but I've got a theory. Back when there were dinosaurs running around, there was a lot of tropical climate on the Earth. Went pretty was towards the poles. Then an asteroid smacks the planet. Nuclear winter and a resulting ice age. The ice receeds and leaves the landscape pretty much as is. But, what if the natural state of Earth is the tropical version the dinos knew and loved? What if this warming they all point to is jut the ongoing correction from the ice age? Just a scientific theory from a lawyer with a lit degree and a military background...
Expand our view beyond 100,000 years, and there simply is no "natural state" for the Earth. The sun is constantly aging and slowly changing it's luminosity and output as it ages along the main sequence for a G-yellow dwarf star.
In the long stretch after the Hadean and late heavy-bomardment period, and well before the Precambrian explosion, the Earth had no oxygen because the early life and types of archea we still find deep in the oceans and rocks was happy with sulfur, cyanides, and other types metabolism. The oceans were green, not with algae, but with dissolved iron that didn't rust for hundreds of millions of years because there was no free oxygen to rust it. Then when by evolutionary accident green chlorophyll was stumbled upon by the mid-level oceanic single-cell organisms because all the green was filtered out by the purple and red stuff living above it, (the sun's output peaks in the green-light spectrum, so in theory, chemical agents that absorb green are the most efficient, while chlorophyll that reflects everything but the green is the least) the oxygen they produced killed most everything else, and then spent hundreds of millions of years rusting all that iron out onto the sea floor, and reacting voraciously with everything else that would oxidize, before it actually approached the rough 20% stability figure we've had since.
And then still before the dinosaurs, before there were fish, or even the trilobites and worms, there's geological evidence the Earth was in an ice-age pole to pole, miles thick because the arrangement of the proto-Pangea continents belted the equator at one point, and cut off all the north-south oceanic heat transport. Eventually some continental drift and super-volcanisim that would make the Yellowstone basin blowing and creating doomsday for humanity look like a fart, broke it up and things changed again.
And while people casually educated with astronomy etc. think "the sun/earth has five billion years left before red-giant etc." that's not really true. The sun has a long time still in the yellow G-spectral class when it'll be a lot hotter, and Earth will probably lose all free water on it's surface and be uninhabitable to multi-cellular surface life within just another 500 million years. Bacteria and archea will likely hang on in the rocks below for billions more, but "life as we know it" we're already at the last quarter to third of "Earth's run" as it were..
That's why the whole "ZOMG, hoomammity iz killun motha erf!" meme in global warming is just absolutely
stupid. And why I KNOW that even the scientists that "believe" in MMGW are dishonest, because they should be educated enough to know that at the worst, if MMGW is real, it will at most "destabilize climate conditions and the biosphere for the easy existence of human civilization". And if we ended, within 10,000 years, which is less than even an eyeblink in geological time, it would be as if we were never here.
That and other issues like how nuclear power is opposed, and even the "doesn't even break even physically or economically lefty green power scams" like solar farms and windmills get opposed for their "environmental impact" tells me that MMGW is not serious science, but 90% lefty politics.
If you could somehow strip away all the bias, crap, and ideological contamination that underpins MMGW research, my gut feeling is that it has a 20% chance of even being real, and if real, a 5% chance of "seriously screwing up things for humanity", and .00001% chance of turning Earth into another Venus.
