The best discussion I’ve seen about the evolution of the planet was that the atmosphere was originally heavy in carbon dioxide and not much oxygen. Then plant life began, and over a few billion years the plants consumed the CO2 and created O2, changing the atmosphere, and making aerobic animal life possible. I assume that process never ended, but the changes in CO2 and O2 are so gradual they can’t be measured. Now suddenly the intelligent animals have figured out how to measure it and are all concerned. How do we know but that Earth has finally reached some sort of equilibrium, and the CO2 and O2 are now varying in a small, sinusoidal pattern of, say, 60 years, causing the temperatures to vary in the same pattern?
Or, have the animals killed enough plants that this change that took a few billion years has been reversed? Is the age of the plants at a minimum and the age of animals peaking? When will we reach a new equilibrium? Or will we ever?
Or, has the Earth given us too few volcanic eruptions over the last 60 years, resulting in too little natural, fine particulates in the atmosphere to screen out just enough sunlight to keep the temperature balanced? And, if this is true, is this due to a gradual cooling of the Earth’s core that results in a gradual warming of the gaseous blanket around the Earth’s crust? Or, is this cutback in volcanic activity a natural and cyclical phenomenon that will reverse itself over the next century? If the Earth’s core is cooling irreversibly, then we are probably down to our last billion years, don’t you think? Or, rather than the Earth’s core cooling, might the crust be hardening and allowing fewer volcanic eruptions?
The issue is extremely complex. I don’t believe the human animal knows enough to say definitively that global warming, if it truly exists, is a human caused, irreversible (or reversible) trend. I personally feel the loss of forests might be a better argument for manmade global warming—if an acre of forest is more efficient than an acre of row crops or pasture at consuming CO2 and producing O2.
Best regards,
NDG
