Please note that I also said "...This is not to say we should ignore economic problems (or environmental problems or whatever). We should still work for positive change. We should still fight to educate our fellow man...."
There’s not only environmental and economic problems, but also a dreadful energy problem.
Any energy used by our various types of engines (except that produced in our nuclear power plants) comes initially from the thermonuclear reactions of fusion of hydrogen into helium in the solar core.
To provide us a work, the flow of energy coming from the sun can go trough different stages : mechanical (winds, marine and river currents, waterfalls… resulting from the Earth heat and climatic engine), chemical, electric or thermal. Initially and during a very long time, only algae and phytoplankton, then since some 450 million years the terrestrial plants also, collected solar energy in chemical form by photosynthesis. It is this energy which makes it possible to synthesize everything that living organisms and their predatory need and which is the engine of the essential part of the life on Earth. The plants reduce the CO2 of the atmosphere on one hand and H2O on the other hand by fixing carbon and hydrogen in the form of organic matter while releasing oxygen in gaseous form.
During a few geological periods, 100 or 150 million years ago, part of this organic matter did not have enough time to be consumed by the predators and be then recycled in carbonic gas and water by breathing. In result of geological events, it was slowly accumulated, transformed and fossilized into oil and coal, which constitute
extremely concentrated fuels: we have to burn 3 to 5 kg of wood to provide as much heat than produced by the combustion a single kg of oil refined in gasoline, fuel/diesel oil or kerosene. This energy corresponds roughly to the mechanical work provided by a score of hard workers during one day, for example 20 oarsmen on a Roman galley!It has taken about 24 tons of fossilized organic matter to generate the one and half kg of oil needed to produce 1 kg of fuel oil or gasoline.
The world consumes actually about 86 millions barrels of crude oil every single day, which corresponds roughly to the contents of 43 supertankers of 2 millions barrels each. Alternative energy sources are just peanuts in comparison. Crude oil is not only necessary for transportation, but also for agriculture (fertilizers production, irrigation, tractors and machines), industrial fishing, heating, industrial production and almost every activity of our civilization. It has permitted a tremendous population growth, to the point that the planet could never nourish a population of 6.5 billions without the extremely concentrated, cheap and convenient energy provided by crude oil.
The fireless paleo lifestyle collapsed. QED.
I don’t know whether the word “collapsed” is appropriate for a process slowly taking place during a few 100’000 years…
Cheers
Francois