Posts by David Haywood
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Southerly: A Tale of Two Iceblocks: Part…, in reply to Moz,
As a GHG methane has the huge advantage that it’s a short-term gas, so if we stop excreting it it’ll be gone in a mere 20 to 100 election cycles. Which may be your confusion?
Perhaps. It's not really so much the methane as the residual carbon dioxide (or not) after the methane has broken down.
There are some aspects of biology that I really enjoy & am somewhat good at; apparently thinking about biomethane isn't one of them.
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Southerly: A Tale of Two Iceblocks: Part…, in reply to Moz,
Right, so in this view there is no energy storage in the tree per se, so there’s no negative tax applied for planting trees or any other carbon-negative activity.
Well, you could say there’s no dirty energy storage in the tree.
The tree, if burnt, would provide mostly clean energy. The tree, if used as a building product, might displace another product that requires more dirty energy to manufacture. The approach taken in my demonstration proposal is to disincentivize dirty energy – rather than the more fraught and difficult route (it seems to me) of incentivizing clean energy.
The idea of using forests for carbon sequestration seems like a wholly separate issue. There’s only a finite amount of land in New Zealand that could be turned perpetually into forest, and so it’s obviously not a long term solution to ongoing greenhouse gas emissions. The question of what proportion of land we devote to perpetual forest – or how much we deforest – seems like a wholly separate political question (though certainly a tax on dirty energy might disincentivize dairy in comparison to forestry, for example).
If I capture CO2 and turn it into methane, I pay PGST on the energy used to do that, but not on the net warming potential in the gas produced.
I may not be following you here. The methane emitted at the landfill, for example, would be charged on a carbon-dioxide-equivalent basis. Theoretically you could also tax ruminant carcasses and milk solids (at abattoirs and dairy factories) on a per kilogram basis at a rate to represent the carbon-dioxide-equivalent of methane emitted during production of their food energy.
You’d only need to focus on big emitters. You wouldn’t worry about home kills or methane emissions from long-drops, of course (much in the same way that we don’t attempt to charge GST on postal orders of trifling value).
EDIT: It’s illegal in New Zealand, of course, to release synthetic refrigerants into the atmosphere, so that’s not an issue that needs to be covered by my demonstration proposal. Though you could certainly explore the possibility of taxing synthetic refrigerant imports on a carbon-dioxide-equivalent basis rather than under the current levy.
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Southerly: A Tale of Two Iceblocks: Part…, in reply to Moz,
This week, this year, this decade, methane is methane regardless of where it comes from. Half life in the atmosphere is between two and five electoral cycles, so as far as the political system is concerned it’s permanent once released.
Here’s what confuses me:
If, as I understand they are, the calculations for greenhouse gas emissions are based on the GWP100 values (global warming potential over 100 years) then how can biomethane be equivalent to fossil methane:
[EDIT: I hadn’t realized that this was particularly recondite information, but I may need to explain that under the IPCC guidelines greenhouse gases are rated according to their global warming potential (GWP) in comparison to carbon dioxide over a given time period. For example, the GWP100 value for methane is 34, because methane has 34 times the global warming effect of carbon dioxide over a time period of 100 years.]
1. Fossil methane breaks down after, say, twelve years, and then spends the next 88 years (of the 100 year GWP period) as carbon dioxide still contributing to global warming.
2. The C in the CH4 of biomethane comes originally from the atmosphere, i.e. it was absorbed from the atmosphere to grow the grass which feeds the ruminants who emit the methane. So when biomethane breaks down after, say, 12 years then the resulting carbon dioxide was just that which was absorbed by the grass in the first place. So there is no net contribution to global warming for the next 88 years by the decomposed biomethane.
So how can biomethane and fossil methane be considered to have the same GWP100?
Maybe there’s some modification factors that are figured in at some basic calculation level, but I haven’t been able to find them.
I may just be confused by all this biological stuff because it’s not my field. Any explanation would be greatly appreciated.
P.S. I also need to resolve this mystery for some other work I’m doing – so my appreciation would be double the normal value!
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Southerly: A Tale of Two Iceblocks: Part…, in reply to Moz,
I’m not convinced that your side notes and implicit “wood as a construction material is energy use” really convey even to me that you intend cutting down that tree in my front yard to incur an energy use tax for the embodied energy in the timber, let alone for the methane release as the waste breaks down.
The PGST you’d pay on the tree would mainly consist of:
* PGST on the petrol (at point of importation or production) to run the chainsaw
* PGST on the diesel (at point of importation or production) to run the hauler and transport to the timber mill
* PSGT on the dirty energy (at point of production) used to run the timber mill (i.e. a proportion of electricity cost)
* PSGT on the diesel (at point importation or production) used to transport the processed timber to its final destinationThere would also be infinitesimal portions of PGST in the final cost of the finished timber due to the PSGT paid on the embodied energy (at point of importation or production) in the chainsaw, hauler, timber mill machinery, and trucks, etc.
If the timber was burnt or decomposed aerobically in the normal way then the resulting carbon dioxide would only be that originally removed from the atmosphere to grow the timber, and therefore no PGST would be payable on these processes (since there is no net release of greenhouse gases).
If the timber rotted anaerobically in a landfill to produce methane then PGST would be payable (at point of production) on the methane emissions by the company running the landfill.
Does that answer your question?
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Southerly: A Tale of Two Iceblocks: Part…, in reply to Moz,
I'm aware that I'm picking at the corners of an argument I wholeheartedly agree with, so I hope that's coming through.
That certainly comes through, Moz -- and it's very helpful! One learns to think a certain way as an energy engineer, and this often makes it confusing when you try to explain things to normal humans. Very helpful having it pointed out where my explanations have been lacking!
It's hosing down with rain here, and I'm currently reading Anne of Avonlea to my daughter. Will respond to the issues you raise ASAP.
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Southerly: A Tale of Two Iceblocks: Part…, in reply to Paul Campbell,
minor nit - I think you mean "milk solids"
Thanks Paul -- that'd be my aging eyes! Now fixed...
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Southerly: A Tale of Two Iceblocks: Part…, in reply to Moz,
Deforestation and other land degradation, farming especially ruminants, clathrate destruction, refrigerant gas releases, etc, are all significant problems that should be included.
Actually (nearly) all of this is included in the numbers that I discussed!
Russia is basically fucked the day we count methane from permafrost and clathrates, as their whole economy is not big enough to buy the offsets required to adjust for that.
This would be the exception in the numbers that I discussed. And this highlights yet again the silly system used in the UNFCCC conventions, alas. That methane is being released because the whole world is heating up – it would be ridiculous to slate it all back to Russia on account of it being released in Russian territory.
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It's worth noting that you have also focussed entirely on energy, so you're ignoring the flatulent bovine in the room.
As I mentioned in my discussion, the methane emissions from ruminants are due to the conversion of solar energy (e.g. via grass) into chemical potential energy in meat. So that certainly is an emission due to energy usage.
The reason I didn't include it in the ballpark calculations is that -- insofar as I have been able to discover -- the UNFCCC approach doesn't seem to distinguish between biomethane from cattle and fossil methane. So it's not clear to me what the true numbers actually are. (I may be wrong about this and would be very happy to be corrected). At any rate, neither calculating nitrous oxide or methane from agriculture is in my field of expertise, and the ballpark calculations could demonstrate what I needed to show without them, i.e. that a PGST could produce the same revenue as the GST it replaces.
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Rob Stowell wrote in the comments for Part 1 of this blog:
A carbon tax isn’t just – or even primarily? – aimed at consumers, but at producers, too, of course. Isn’t it possible that the NZ iceblock [exporters] will (in response to a carbon tax) even further reduce their dirty energy consumption, install a wind generator, avoid any carbon tax at all and end up doing ok...
Hopefully this second part of my blog explains an alternative approach to this now, Rob (see the discussion on exports in Section 3). I couldn’t really explain it before without posting the whole thing. There are certainly methods (as described) of not imposing a carbon tax or emissions cost on exports (within a given industry category) – while at the same time providing an incentive for exporters to minimize their consumption of dirty energy.
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I realize that I’ve doubled-down on the emotion-laden issues here—not only discussing anthropogenic climate change but also taxes!
As before, could I politely request that we avoid a stooshie about whether the climate scientists and atmospheric physicists are right or wrong – and concentrate purely on the subject of discussing methods for reducing New Zealand’s consumption of dirty energy without causing an increase in global greenhouse gas emissions.
Let the animadversions begin...