ᐅ About Passive Houses, Plastic Bags, and Styrofoam Cladding

chand1986 schrieb:
Karsten, the issue is what happens to the overall balance (!) of all biomass use within a defined period. If this is zero—that is, if as much biomass grows back as is burned during this period—it is neutral.

If people burn first and plant later, the world has to deal with extra CO2 (and fewer trees) for 50–100 years (the time it takes the tree to grow). This is the time factor. Simply planting a new tree for every one burned is insufficient.
A forest from which only as much is harvested as grows back overall between two harvests makes sense. But burning one tree and then planting one is not.

Time factor: If a typical tree takes 50 years to grow and you want to heat with wood, you need a small forest (!) that has the same biomass as at the start when harvested after 50 years.

Because of the time factor, one burned tree and one planted tree do not make you CO2 neutral within reasonable timeframes. It’s not possible.

And if timeframes didn’t matter—that’s my argument—then oil and coal would also be considered good again, since they are recycled products too, just on a million-year timescale.

I doubt wood is so much better or more ecological as a fuel, for these reasons. Even environmentalists spread a lot of nonsense. Burning anything is simply not the best solution, no matter what.

Two points overlooked:

A) Increased CO2 levels in the atmosphere accelerate plant growth. The time until balance is reached is shorter.

B) There are already technical options to quickly convert CO2 from the atmosphere into fuel. (Electricity electrolyzes water, producing hydrogen and oxygen; hydrogen can be combined with CO2 on an industrial scale to make methanol, gasoline, or diesel.) This allows the carbon cycle to be closed within minutes.

Point B) currently has no lobby. With all the CO2 and climate change panic, more money can (still) be made otherwise. Think for yourself, don’t just repeat what you hear!

Marvinius II schrieb:
Two points overlooked:

No.

Marvinius II schrieb:
A) Higher atmospheric CO2 levels accelerate plant growth. The time until balance is reached becomes shorter

No.

Marvinius II schrieb:
B) There are already technical possibilities to convert CO2 from the atmosphere into fuel on a short-term basis.
(Electricity electrolyzes water, producing hydrogen and oxygen; hydrogen can be industrially combined with CO2 to produce methanol, gasoline, or diesel)

Yes.

Marvinius II schrieb:
This allows closing the cycle within minutes.

No.

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Explanation:

A) is incorrect because the rate of a process, say dc(CO2)/dt, can only say something about the ratio of "times until balance" if the amounts of CO2 to be consumed are identical. But these amounts are not identical if you claim that more CO2 would shorten that period (more compared to what?).

The more CO2 there is, the faster the growth, but also the greater the amount that must be consumed to reach balance. Since on the way there the concentration inevitably passes the level it is being compared to (from which point the functions are identical), it can never be faster, only slower.
Therefore, more CO2 always requires longer to be balanced than less.

B) is partly correct. The technology exists but consists of a sequence of low efficiencies (water electrolysis, fuel synthesis with hydrogen, fuel utilization).
The question is how large the CO2 share is of the initial primary energy input to keep CO2 in the closed cycle. If we had abundant CO2-free energy generation, the method would be fine.
With an energy mix that also includes gas and coal, the calculations get complicated. How does the balance look? Do you know? I claim it’s ineffective.
Efficiency chains with multiple steps quickly lead to poor total efficiency. And only that matters!

Marvinius II schrieb:
Just think instead of repeating

Thanks, but no thanks

chand1986 schrieb:

The more CO2, the faster the growth, but also the higher the required consumption until balance is reached.

Could you please explain this again for those of us without a technical background? Are you assuming that CO2 consumption is proportional to growth? If so, is that a realistic assumption? After all, plant growth depends on more than just CO2...

I admit, now I can only watch in amazement because my Kielä Gesamtschulabi Friedrichsort, right behind the armored vehicle factory, no longer covers this.

Nordlys schrieb:
I admit, now I’m just watching in amazement because my Kielä Gesamtschulabi Friedrichsort, right behind the tank factory, no longer covers this.

A simple analogy will do.

If you turn on two identical stove burners for exactly 3 minutes, one on level 9 and one on level 5, after turning them off you have one burner that is just warm and one that is hot.

When they start to cool down, the hot burner loses temperature initially much faster compared to the merely warm one (for example in °C per minute). Still, it takes longer to cool down completely compared to the other burner. The reason: the functions describing the temperature loss per time, depending on the current temperature, are identical for both burners. So it doesn’t help to start faster just because you were hotter—you are always behind.

Replace "temperature" with CO2, "cooling function" with plant growth, and the two differently heated burners with two states having more or less CO2.

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kaho674 schrieb:
Are you assuming here that CO2 consumption is proportional to growth? If so, is that realistic? Plant growth doesn’t depend on CO2 alone...

It is approximately proportional. The reason that A) is still not correct is different, as I described above.

chand1986 schrieb:

It is roughly proportional.

Considering the current level of CO2 pollution, that would imply that the few untouched forests on Earth are growing at an exorbitant rate. I have my doubts about that. Other factors, such as water availability and simply lack of space or light, serve as natural limits in my opinion, which cannot be easily overlooked, even on a global scale. Rainforests cannot grow to the sky, even though they regularly try. Where there is one leaf, another cannot exist, and so on.