"Net Zero"

[flameport]

"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"

Plus a whole load of additional energy to create the 10 litres of ultra high purity water required for every 1kg of hydrogen produced, and even more energy to compress the hydrogen gas so it can be stored, and then yet more to distribute the hydrogen to where it is required, and then another pile of losses when it's either burned or used in a fuel cell stack to create electricity.

 

[flameport]

with polymer electrolytes and all sorts of break through technology.

PEM electrolysers are not 'break through technology'. They have been around for over 50 years.

 

[mikeey84]

Plus a whole load of additional energy to create the 10 litres of ultra high purity water required for every 1kg of hydrogen produced, and even more energy to compress the hydrogen gas so it can be stored, and then yet more to distribute the hydrogen to where it is required, and then another pile of losses when it's either burned or used in a fuel cell stack to create electricity.

Well yes, and the cracking of oil into petrol takes a vast amount of power, as does the compression and distribution of LPG. Hydrogen is not perfect by any means, and low carbon Hydrogen is impossible without a significant amount of low carbon power

 

[RandomGrinch]

And as for the future...
Another incremental step has been made towards fusion power:

Korea fusion project sustains plasma at over 100 million K

Plasma at over 100 million kelvin for 20 seconds adds to list of noteworthy fusion breakthroughs in 2022

www.theregister.com

There are some CO2 predictions for the total carbon footprint of fusion power stations (abstract here, albeit from 2000):

ShieldSquare Captcha

iopscience.iop.org

Apparently it will be less than current PV solar and less than double that of current fission production, with 70% due to construction activity.

Interestingly, the first (of many) results when searching Google for 'carbon footprint for fusion power' brings up the slightly ambiguous statement from the IAEA:

"There are no CO2 or other harmful atmospheric emissions from the fusion process, which means that fusion does not contribute to greenhouse gas emissions or global warming."

I guess, we'll have to wait another thirty years ( ) to see

 

[JohnW2]

Interestingly, the first (of many) results when searching Google for 'carbon footprint for fusion power' brings up the slightly ambiguous statement from the IAEA:
"There are no CO2 or other harmful atmospheric emissions from the fusion process, which means that fusion does not contribute to greenhouse gas emissions or global warming."

In what sense do you regard that as 'ambiguous' - perhaps because it talks only of the in-service 'emissions' (or the lack of them), without considering construction etc. processes?

I suspect that those human beings who work in such facilities will probably 'emit' some CO2

I guess, we'll have to wait another thirty years ( ) to see

Who knows? My first reaction would be to suggest that is pretty optimistic' - but, on the other hand, some technological advances have happened much more rapidly than we would ever have anticipated.

Kind Regards, John

 

[RandomGrinch]

In what sense do you regard that as 'ambiguous' - perhaps because it talks only of the in-service 'emissions' (or the lack of them), without considering construction etc. processes?

Yes, that was what I meant by ambiguous. Which again contributes to the 'messy' ness of CO² calculations.
(I'm sorry, the bold in the quote wasn't mine, I should probably have highlighted the last part of the sentence!).

 

[JohnW2]

Yes, that was what I meant by ambiguous.

Thanks for confirming.

Which again contributes to the 'messy' ness of CO² calculations.

Quite so. Looking back, I'm not sure that I've done a very good job of making my point about the importance of the definition(s) of "Net Zero", so I'll try to clarify ....

... I can but presume that the ultimate hope/goal is that we might one day reach the day at which atmospheric CO2 levels do not rise further at all. To achieve that, it would be necessary that we had "true" "Net Zero", and I'm far from convinced that the "Net Zero"s of politicians and some industries actually amount to that.

In particular, I suspect (but do not know) that some of their definitions of "Net Zero" possibly/probably exclude many/most of the 'emissions' of CO2 into the atmosphere which are largely/essentially 'beyond our control' - things like the CO2 breathed out by humans and 'wild' animal life, that released into the atmosphere by decay of dead animals and plants, volcanic eruptions etc. etc. (and maybe also overlooks some of the 'natural' processes which remove CO2 from the atmosphere). Having said that, I have no idea how significant those 'unavoidable emissions' are in relation to the big picture - so it could be less important than I fear.

Is that perhaps a little clearer?

Kind Regards, John

 

[Munroast]

CO2 emissions from life do not matter as they are simply emissions of CO2 that have only recently been borrowed from the atmosphere.

CO2 from volcanoes is completely out of our control, but in the long term are balanced out by what is being absorbed into our oceans (life dies, falls to the bottom and eventually becomes rock, that in many hundreds of million years may be released back in the atmosphere as CO2) It is all entirely out of our control

CO2 from fossil fuels is the only concern, this was vast amounts carbon taken from the atmosphere and locked deep underground since the Carboniferous period (200-400 million years ago) we don't want it back in the atmosphere. CO2 was believed to be in the region of 1500ppm back then and that would not be good now.

 

[mikeey84]

I have no idea how significant those 'unavoidable emissions' are in relation to the big picture - so it could be less important than I fear.

Not very significant compared with the avoidable emissions

I can't vouch for the veracity of these figures, but to give a sense of scale:

• Humanity's annual carbon emissions through the burning of fossil fuels and forests, etc., are 40 to 100 times greater than all volcanic emissions

 

[JohnW2]

CO2 emissions from life do not matter as they are simply emissions of CO2 that have only recently been borrowed from the atmosphere.

They (in addition to all the other factors) 'matter' arithmetically if it is our aim to achieve the situation in which there is no further increase in atmospheric CO2, since they are part of the overall balance.

CO2 from fossil fuels is the only concern ....

The burning of fossil fuels is obviously the greatest current factor, and it's very possible that substantial elimination of it would enable us to achieve an equilibrium situation between natural processes (both producing and removing CO2), perhaps even without the need for any 'new technology, such that the rise of atmospheric CO2 was completely eliminated - i'e' true "Net Zero".

Do you have any idea as to when atmospheric CO2 levels were 'stable' (unchanging) for a number of decades?

However, I don't think that any of the above alters what I've been saying about the arithmetic and definitions. Since true "Net Zero" is what is required to achieve an equilibrium state, it is hard to 'see the wood for the trees' if politicians/whoever are talking about a "Net Zero' which excludes some, or many, of the factors just because they are 'beyond are control' - 'within our control' or not, they are part of the equation.

Kind Regards, John

 

[JohnW2]

Not very significant compared with the avoidable emissions

As I said, I have no idea about the relative contributions of different types of 'emissions' - but, when I have some moments, I'll see what I can find out.

I can't vouch for the veracity of these figures, but to give a sense of scale: Humanity's annual carbon emissions through the burning of fossil fuels and forests, etc., are 40 to 100 times greater than all volcanic emissions

OK, if that's true, it's one of the factors, although I might suspect that the 'biological' ones are perhaps appreciably more important than volcanoes - as above, I'll see if I can find anything approaching 'chapter and verse'.

Kind Regards, John

 

[RandomGrinch]

However, I don't think that any of the above alters what I've been saying about the arithmetic and definitions. Since true "Net Zero" is what is required to achieve an equilibrium state, it is hard to 'see the wood for the trees' if politicians/whoever are talking about a "Net Zero' which excludes some, or many, of the factors just because they are 'beyond are control' - 'within our control' or not, they are part of the equation

I totally agree - the arithmetic to get to true "Net Zero" is obviously complex, and I'm sure there are some very intelligent people and algorithms working on these numbers behind the scenes.
But without a definition of what is counted, or what is legitimately left out of the equations, it seems (and I may be wrong), that many businesses/organisations/politicians/etc. are free to define the equation in a way that best suits their narrative.

 

[JohnW2]

I totally agree - the arithmetic to get to true "Net Zero" is obviously complex, and I'm sure there are some very intelligent people and algorithms working on these numbers behind the scenes. But without a definition of what is counted, or what is legitimately left out of the equations, it seems (and I may be wrong), that many businesses/organisations/politicians/etc. are free to define the equation in a way that best suits their narrative.

All largely true, although I would personally say that if one wants attempt to do the calculations as 'properly'/accurately as possible, there isn't really anything which can be "legitimately left out". It's bad enough having to live with some things which are largely unknown and/or not easily quantifiable, without 'adding insult to injury' by deliberately 'leaving out' some things which are relatively 'known'.

I fear that what the "businesses/organisations/politicians/etc." (and hence all the people who pay attention to them) may be missing (or perhaps deliberately keeping quiet about!) is that, unless we want to be 'selfish' the ultimate goal must be achievement of true "Net Zero" (or even "Net Negative") - since, if we don't reduce the rate of rise of atmospheric CO2 to zero (or negative), we would merely be shifting the consequences we fear (due to 'global warming') to future generations - and, as I keep saying, I'm far from convinced that the "Net Zero" being talked about by the "businesses/organisations/politicians/etc.".

In passing, in relation to my "or negative" comments above, I wonder if there is any need to think about the consequences of 'going too far'? When I was at school, a decade or three before anyone had heard anything about "global warming", some of the then "experts" were seemingly getting quite concerned that the world might be heading towards another "Ice Age"!

Kind Regards, John

 

[Munroast]

Do you have any idea as to when atmospheric CO2 levels were 'stable' (unchanging) for a number of decades?

this may be the first time in the history of our planet where CO2 levels have not been stable over "Decades".

Yes, there has been times over the last million years (since records were explorable) that levels have risen by 100ppm, but this was over millennia, not decades.

There is no real reason why human civilisation could not exist at double or treble the current levels of CO2, the problem is getting there. Climate change will significantly change where we can grow food, rich agricultural areas will fail and food will need to be produced in other places, as we are already on the limit of what we can practically produce, these changes will cause famine and war. and then there is the problem of sea levels rising and huge cities (even countries) needing to find somewhere else to live. Humans can't cope with inward migration, and Mass migration will be essential - wars will soon ensue and economies will collapse. It's not going to be pretty


Climate change will not kill us, we will kill each other because of climate change!

 

[JohnW2]

this may be the first time in the history of our planet where CO2 levels have not been stable over "Decades".

That what I thought - albeit, as you go on to say, the situation has been much less stable if one looks at much longer timescales. Hence what I said (and everyone seems to assume) is undoubtedly right - that if we could get close (globally) to eliminating the burning of fossil fuels, we could probably get something like true "Net Zero" (stable CO2 levels), even without needing any 'new technology' to reduce C02 levels.

The (practical) problem is obviously that anything even remotely approaching elimination of (global) use of fossil fuels is not going to happen overnight, nor even over a few decades, and that remains true no matter what any individual small country may do/achieve - so that is presumably why there is increasing interest in those 'new technologies' as a means of hopefully mitigating the situation to some extent whilst waiting for the gradual (and probably slow) reductions in fossil fuel usage to progress to a useful extent.

Kind Regards, John