On one level, that's a pile of wood.
But you can also see it as "stored chemical energy". If and when I burn it, I will be releasing energy from the sun that was trapped and converted to wood a century ago. By reversing the process that happened a century ago, I will be warming the atmosphere slightly.
Light energy -> chemical energy -> light energy and heat.
So the reverse must also hold. A century ago, the tree was cooling the atmosphere by converting light energy (which otherwise would have been converted to heat) into chemical energy. That's why it's cooler in woods and forests, and why allowing them to grow will cool the atmosphere, however slightly. (The fact that they also trap CO2 is a very minor issue).
Saturday, 16 May 2020
Burning Down The House
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17 comments:
What part of the house have you converted into firewood?
B, the neighbours are doing stuff, they said I could help myself as it will all go in a skip.
Similarly if you were to burn some coal, that represents some sunlight that was trapped into a plant c. 300m years ago, and would have otherwise warmed the earth a bit more. So burning it now merely returns the planet to the equilibrium that existed then. When it did not spontaneously combust, or turn into Mercury or Venus.
S, exactly!
I think many people are under the impression that burning fossil fuels somehow releases 'new' CO2 into the atmosphere, that was never there before. When in fact all we are doing is putting it back where it came from. Admittedly after a 300m year hiatus, but when the planet is 4.5bn years old, thats not an overly long time. For over 90% of its existence there wasn't any CO2 locked up in fossil fuels, and the planet survived just fine.
S, sure, they admit that CO2 has been thousands of parts per million in the past, but rather conveniently, the sun was slightly dimmer then so it cancelled out. It's only ever the CO2!!
And you may have seen that F1 and others are working on petrol made from CO2 extracted from the atmosphere plus Hydrogen ditto by electrolysis driven by sunshine or wind. That is 'carbon neutral' petrol.
L, is it expensive?
MW. It will be initially as it is small batch production. But like all these things it will be developed and the price will come down.
L, it will probably end up being made in those parts of the world with lots of sunshine and empty spaces to put the solar arrays, funnily enough, where we get our oil from at the moment.
B, wot?? From the North Sea? I couldn't think of a worse place.
B. Or from wind - in which the UK is rich. Wind leccie was quoted in the snippet I saw.
I really don't think the North Sea has a reputation for being somewhere with lots of sunshine, although, around the edges, you might see people there with pieces of cloth on their heads, too.
B, c'mon man, I was referring to the last bit "funnily enough, where we get our oil from at the moment". :-)
S, in fact there is quite a lot of evidence to show that fossil fuels are only "fossil" in the C18th sense of "that which is dug out of the ground" and that they were formed when the earth was formed, as methane. Over the intervening millions of years, as part of the sesmic changes in the Earth's crust, the methane has been slowly stripped of more and more of its hydrogen to form heavier and heavier molecules until all the hydrogen is stripped away and we are left with pure carbon - coal. This process has been proceeding at diffferent speeds in different strata, with the result that some strata bear methane, some oil and some coal. There is, in fact, very little evidence for the plant-based origin of hydrocarbon fuels.
B, I have heard of that theory in passing. It seems plausible that oil was created this way, but coal is almost certainly compressed plant material.
The theory, which I don't claim to have understood or remember, explains why most of it is about 300 million years old. Before and after that, conditions weren't right to allow it to be created.
'Tis here: https://www.goodreads.com/book/show/853851.The_Deep_Hot_Biosphere
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