"Net Zero"

[Munroast]

[ In passing, everyone seems to talk about trees as if they were the main natural remover of CO2 from the atmosphere, but I thought it was the case that we now believe than algae in the oceans are more important biological removers of CO2 from (and 'putters' of oxygen into) the atmosphere, and also that geological removal of CO2 and dissolution of CO2 in the oceans are also major factors? ]

Kind Regards, John

Yes the Oceans are a very very important CO2 remover, but they are out of our control, we can't increase this at our will. And worryingly the warming and acidification of our oceans means they will be less effective (absorb less)

Where as with trees we can simply plant them, and we have vast amounts of open moorland (which mostly is areas of deforestation from 4,000 years ago) We have plenty of scope to plant trees.

Scotland has 3 million hectares of moorland (nearly half is grouse moor for a handful of wealthy shooters)
Allowed to generate to its natural state of Caledonian Forrest, it would be absorbing in the region of 60 million tones of CO2 per year
(Scotlands CO2 output is around 40 million tonnes)

 

[Munroast]

For what it's worth, I agree. It's far more complicated than one might first think - particularly since, as I have suggested above (and despite what some people have said), even the meaning of "Net Zero" does not seem to be clearly defined.

Kind Regards, John

of course it is not clearly defined, it will have been purposefully left a bit vague to give wriggle room (as well as keeping the lawyers wealthy)

Another big vagueness is place of manufacture versus place of use. If we buy a car made in Korea made out of steel smelted in China and then shipped to the UK. Can we really point to China & Korea and say they are polluting the environment ?

 

[Swwils]

Once you have enough energy just simply burn the CO2 back to carbon. Avoiding any much worse CO generation of course.

 

[JohnW2]

Yes the Oceans are a very very important CO2 remover, but they are out of our control, we can't increase this at our will. And worryingly the warming and acidification of our oceans means they will be less effective (absorb less)

That makes sense. Acidification is clearly an issue (and somewhat of a vicious circle, since dissolving more CO2 will, in itself, lower pH), as is warming of oceans. However, as for the later, it will presumably be partially compensated by the fact that the same processes leading to warming of oceans will lead to rising sea levels (hence increased ocean volumes, hence increased CO2 storage capacity) - but I don't know enough of the parameters to do the sums for that 'balance'.

But what about the algae I mentioned? Am I not right in saying that they are a significant part of the CO2-removing equation? If they are, it would not surprise me if they were to at least some extent 'self-adjusting', in that they could well proliferate, (hence increase in numbers and CO2-removing capacity) if atmospheric CO2 rose?

Where as with trees we can simply plant them, and we have vast amounts of open moorland (which mostly is areas of deforestation from 4,000 years ago) We have plenty of scope to plant trees. .... Scotland has 3 million hectares of moorland (nearly half is grouse moor for a handful of wealthy shooters) Allowed to generate to its natural state of Caledonian Forrest, it would be absorbing in the region of 60 million tones of CO2 per year (Scotlands CO2 output is around 40 million tonnes)

I'll have to take your word for the numbers.

Trees presumably represent a very dynamic, hence necessarily 'perpetually ongoing', situation, since they represent only 'temporary' (albeit quite long-term) carbon storage. Whenever leaves fall and decay, or when the tree ultimately dies and decays, a substantial proportion of the stored CO2 is presumably returned to the atmosphere as CO2?

... but, again, what about algae? It seems that some people believe that they would/could represent a more efficient CO2-removing strategy, in that (they say), one could get more CO2 extraction per hectare with algae than by planting trees. Is that possibly true?

Kind Regards, John

 

[JohnW2]

of course it is not clearly defined, it will have been purposefully left a bit vague to give wriggle room (as well as keeping the lawyers wealthy)

Undoubtedly true, but I'd say that it's been left a lot more than 'a bit' vague, which makes it very hard to work out what the 'targets, or even strategies, actually mean.

Furthermore, given that many of the significant factors are 'global' (oceanic, geological, volcanic, animals/humans etc.), I'm not convinced that one can very meaningfully talk about (some definitions of) "Net Zero" in relation to a single nation (like the UK).

Kind Regards, John

 

[JohnW2]

Once you have enough energy just simply burn the CO2 back to carbon. ....

Kind Regards, John

 

[Munroast]

That makes sense. Acidification is clearly an issue (and somewhat of a vicious circle, since dissolving more CO2 will, in itself, lower pH), as is warming of oceans. However, as for the later, it will presumably be partially compensated by the fact that the same processes leading to warming of oceans will lead to rising sea levels (hence increased ocean volumes, hence increased CO2 storage capacity) - but I don't know enough of the parameters to do the sums for that 'balance'.

But what about the algae I mentioned? Am I not right in saying that they are a significant part of the CO2-removing equation? If they are, it would not surprise me if they were to at least some extent 'self-adjusting', in that they could well proliferate, (hence increase in numbers and CO2-removing capacity) if atmospheric CO2 rose?

there is a very well put together explanation of how the process works here

When it comes to sucking up carbon emissions, ‘the ocean has been forgiving.’ That might not last

The ocean helps relieve our atmosphere of a lot of the excess carbon dioxide we've pumped into it. Here's how its "twilight zone" makes that happen, and how the impacts of climate change make it harder for the ocean to do its job.

www.pbs.org

 

[RandomGrinch]

Once you have enough energy just simply burn the CO2 back to carbon. Avoiding any much worse CO generation of course.

Coincidentally, we have a research group doing exactly that!
Although I have to say, sourcing the supply of ultra high purity methane/hydrogen mix, and powering a massive microwave (plasma chemical vapour disposition system), isn't exactly carbon neutral.
The resulting diamond films aren't half bad though!

 

[winston1]

If the process of using electrolysis is used it creates both gases from anode & cathode

Doesn’t that use as much energy as is got back when you burn it?

 

[mikeey84]

Doesn’t that use as much energy as is got back when you burn it?

At the moment it uses more. Quoted efficiencies are between 70-85%, with some small scale researchers getting upwards of 90% in new processes.

"A kilogram of hydrogen holds 39.4 kWh of energy, but typically costs around 52.5 kWh of energy to create via current commercial electrolyzers"

 

[Swwils]

Kind Regards, John

At 3320 degrees C or so you can dissociate the CO2 back to carbon.

The main issues are the energy required to do this, the relatively low density of the atmosphere and a few degrees either side and it will just output the much worse carbon monoxide.

 

[chivers67]

Doesn’t that use as much energy as is got back when you burn it?

The whole idea is to produce it in a Green method via wind or water turbine or Solar rather than use a battery or electricity produced by Carbon. Why are you people only quoting part of my post!?! It's about getting it to become more efficient.

watch this it's quite fun

 

[mikeey84]

The whole idea is to produce it in a Green method via wind or water turbine or Solar rather than use a battery or electricity produced by Carbon. Why are you people only quoting part of my post!?! It's about getting it to become more efficient.

watch this it's quite fun

I think it's got a great future, as it can be dialled up and down depending on availability of excess power from renewables.

 

[JohnW2]

At 3320 degrees C or so you can dissociate the CO2 back to carbon.

Indeed (but I have to take your word for the actual temp), but that does not correspond with any definition of "burning" that I am aware of.

However, is there not a fundamental flaw in that approach (rather than more 'easily' storing CO2 as itself or as, say, calcium carbonate)? I don't think that the Laws of Physics would allow the recovered carbon to be 're-burned' (to generate electricity - and more CO2!) without a net loss of energy, since, if one could do that, one would presumably effectively have a 'perpetual motion machine', wouldn't one?

Kind Regards, John

 

[JohnW2]

there is a very well put together explanation of how the process works here

When it comes to sucking up carbon emissions, ‘the ocean has been forgiving.’ That might not last

The ocean helps relieve our atmosphere of a lot of the excess carbon dioxide we've pumped into it. Here's how its "twilight zone" makes that happen, and how the impacts of climate change make it harder for the ocean to do its job.

www.pbs.org

Thanks. That seems to be consistent with what I was saying.

Kind Regards, John