Quote from james_bond_3rd:
Ok, so this is a maybe. There is no proof that organic farming has advantage in terms of energy efficiency over conventional farming. But if you insist I won't argue. The scientific evidence is not there either way.
Itâs just as much a matter of economic efficiency as it is energy efficiency. If a farm uses biodiesel that is made from crops grown on the farm itself, the farm may be more economically efficient, i.e., more profitable, than it would be if it used petroleum.
Also consider that it would be very easy to use solar energy for things like wood kilns and crop dryers that would use petroleum on a conventional timber plantation or farm. Solar energy is not as concentrated as a gallon of gas so it is not as energy efficient in this regard. But if the solar is free it doesnât matter how much of it you have to use to serve your purpose.
And in a broader sense organic farming is more energy efficient in that it does not use fertilizers, pesticides and other agro-chemicals that are dependent on petroleum. In my home garden I could spend about $15 for a chemical pesticide that would last me an entire year and have contaminated produce. Or I could spend less than $10 for some parasitic wasps that almost totally eliminate insect damage in my garden for an entire year. And if my garden were large enough to be self-sustaining I would have to buy the wasps only once and they would naturally reproduce in my garden.
However, it takes energy to extract energy from such waste.
True. But consider that biodiesel, solar, wind and other alternatives can be used in place of petroleum when making biofuels. It takes more energy to heat corn enough to make ethanol than the resulting ethanol contains. So if you have to use petroleum to make the ethanol you have a net loss in energy. If you use biodiesel, solar, wind or some other alternative you have no net loss of petroleum-based energy when you convert wastes to alternative fuels. Furthermore you can make biodiesel and biomethane (from biomass wastes, manure and sewage) in most of the country without needing any energy input for much of the year, and what energy is needed can easily be solar. Any home with enough solar exposure could easily convert its sewage into biogas methane simply by putting the digester in a greenhouse.
When you add the total energy cost of collecting, transporting, and the energy cost of producing the chemicals needed for energy extraction, it's not really worth it.
Making biodiesel is the only biofuel process I know of that needs any chemical input. Converting waste materials into biogas methane is a totally natural process- it happens whenever a collection of biomass is allowed to decay in an oxygen-free environment that is warm enough for the bacteria involved to operate. And why not make biogas out of sewage when you have to collect, process and dispose of the sewage anyway? Converting it to biogas is far more economically efficient than conventional treatment methods are- itâs a simple process that does not need industrial equipment. The Walt Disney company has been converting the sewage from its Florida theme parks into methane for over 30 years. It must be economically efficient or Disney wouldnât be doing it.
The only way this could work, is to return to the life styles of 1800's, and each family have their own methane gas light generated from their decomposed wastes. It's just not worth doing it on an industrial scale.
What about Disney? Mickey Mouse doesnât live in the 1800s.
I gave you two examples, big bang and tidal waves. How do you do a control experiment on tidal waves?
You build a wave tank that mimics the natural landscape. However, the entire earth is too complicated to effectively mimic in a laboratory setting. You could not create a duplicate earth in order to test the effects of human activity on the earth we have.
I can give you more examples: plate tectonic,
We think that plate tectonics work simply from observation. But do we know how (and why) they work without experimentation?
discovery of dinosaurs (and other extinct species), helical structure of DNA.
Mere observations. Tell me how the dinosaurs got here without doing an experiment.
DNA is simply a matter of chemistry- based on natural laws we can observe; no experimentation is needed to document its structure. It did take experimentation to document the role DNA plays in genetics.
Don't tell me that none of these examples is science. They all are.
They are all observations, not explanations.
You're confused. I said observation can substitute for experimentation.
Then what observation tells us that humans are the cause of global warming? How did the last ice age end without man-made greenhouse gases?