What must have been the composition of the atmosphere all those hundreds of millions of years ago for all that carbon dioxide to have been removed from the atmosphere and sequestered as biological matter, to then be buried and reacted to form vast quantities of hydrocarbons.
2.5 billion years ago the earth would have been uninhabitable to most modern life. Single celled life evolved in those conditions and began creating glucose and oxygen from CO2 and water. When those primitive lifeforms died some of them became oil and the CO2 was sequestered.
Over time the CO2 levels dropped until about 20 million years ago the CO2 levels fell to about 300ppm. That's when life as we know it really took off. Yes, it took BILLIONS of years to get there.
Humans have only existed for about 200k years. During that time our CO2 levels have mostly been below about 280ppm. The are now at 429ppm and are rising exponentially. [0]
In the beginning, the oceans were acidic, because they were formed by the condensation of volcanic gases, which consisted of water, carbon dioxide, sulfur dioxide and hydrogen sulfide, hydrogen chloride (i.e. hydrochloric acid) and a few other less abundant acids.
In time, the oceans have become less and less acidic, by dissolving from the volcanic silicate rocks the oxides of the alkaline metals and alkali earth metals, i.e. mainly of sodium, potassium, magnesium and calcium. This dissolution has affected both the rocks on the bottom of the oceans and the continental rocks, where rain has washed the soluble oxides, transporting them through rivers to the oceans.
At some point, so much of the alkaline and alkali earth metals from the volcanic rocks have been dissolved that the oceans have become slightly alkaline instead of acidic, like they are today.
At that time, the carbonates of calcium and magnesium have precipitated from sea water, forming sedimentary rocks. Also around that time, many living beings have evolved mechanisms for controlling this precipitation process, in order to build skeletons for themselves. This has resulted in the fact that many sedimentary rocks are not formed by direct precipitation from sea water, but by precipitation from sea water into skeletons, followed by depositing on the bottom the skeletons of dead living beings.
Now, with increasing concentration of CO2, there is the danger that the oceans will become so acidic as to reverse this, dissolving again a part of the carbonate rocks, including the skeletons of many living beings that are made of carbonates.
There is an equilibrium between the concentration of CO2 in water and in air, depending on temperature and pressure. When the CO2 from water precipitated with calcium or magnesium into rocks, that has drawn more CO2 from air into the water, until a new equilibrium was reached, at a reduced concentration of CO2 in the air. If carbonates would be dissolved by acidic sea water, that would liberate CO2, a part of which would go into the air, further increasing the concentration there.
Thus the formation or destruction of carbonate rocks and skeletons adds a positive feedback to the changes of the CO2 concentration in the air, which has the potential to be bad for us.
Even worse is the fact that this is only one of multiple positive feedback mechanisms that can be triggered by changes in the CO2 concentration in the air, which make very difficult or impossible any long term predictions.
It was the primary driver until life happened. Then life was, and now they exist in a delicate balance.
I get the idea that the throwaway account was suggesting we can just "do whatever forever" without consequences though, and that's just not true. Most CO2 sequestration on earth is now biological in origin and has been for a very long time.
I know, I have one of those weird H shaped flasks with the plat electrodes.
I also have a gas bbq, yet couldn't fill up a LNG car at my house. Maybe there's something more to it than just making small amounts of room temperature / pressure H2.
Round trip efficiency of hydrogen is at best 50% and at worse half that. You have the horrendous efficiency of electrolysis and then the equally bad efficiency in the fuel cell.
Efficiency pumping your excess solar into the EV itself is more like 80-85%, most of which is loss in the electronics, not the battery - those typically have a coulombic efficiency of over 95%.
Hydrogen a boondoggle. It's not nearly as stupid as making ethanol from corn (which is an energy-negative process) but it's close.
Also, "gas fitter and metal fabrication" experience isn't worth anything unless it was hydrogen-specific. It is far leakier than natural gas/propane. One of the biggest hassles of a hydrogen fuel chain is that the stuff leaks through everything.
> Round trip efficiency of hydrogen is at best 50%
In fact, even this level of efficiency may be sufficient. Solar panels are so cheap that if we had affordable, long-term energy storage options, even with such efficiency, we would have completely abandoned fossil fuels. But, unfortunately, storing hydrogen is difficult and dangerous. It is not like natural gas.
> It's not nearly as stupid as making ethanol from corn (which is an energy-negative process) but it's close.
Ethanol is produced from corn not for energy purposes, but for food security. It's like a placeholder for real corn so that if there's a crop failure for a couple of years, the low-iq idiots who think it's stupid to make ethanol from corn don't starve to death.
Well... How successful is the US in cutting ethanol consumption on the years the corn production is lower?
Meat usually does that stabilizing. Fuel consumption not even is almost completely inelastic, but corn ethanol on the US is subsidized on every stage to the point that market forces become meaningless.
> Ethanol is produced from corn not for energy purposes, but for food security
Source? First time I read this, might make sense. Although I don't see how this corn should be unaffected by crop failure if all other corn harvests failed.
> Although I don't see how this corn should be unaffected by crop failure if all other corn harvests failed.
I believe the argument being made here is "we need to overproduce corn in order to get food security; what can we do with the spare capacity in the good years given we're already eating too much?"
I don't know if this argument is correct, but I believe that's what's being claimed.
Yes, this is literally bribing farmers (extremely cheaply) so that in the event of a prolonged crop failure they will have more arable land and equipment to cultivate it and compensate for the crop failure.
I'm a tradesperson with knowledge-worker experience.
Had a software company offer me a position, tech support + some maintenance of existing codebase. I have a demonstrated capability to meet the requirements. Remote + onsite work at client premises. Existing employees doing the roll are way overloaded and obviously stressed.
The person I'd report to travelled to interview me. This person admitted they hadn't received a pay rise in four years.
I told them my current pay grade BEFORE the interview.
Their offer: $45,000 BELOW my current pay, then another $5000 per year I'd spend paying for my dependants to be cared for during the time suggested I'd be at clients premises.
