The Farm Bill is likely to pass in coming months and it is arguably the most important climate bill Congress will address this session. To talk about the climate impacts of agriculture & the opportunities in the Farm Bill, I talked to Peter Lehner of Earthjustice.
I listened to this twice to make sure I didn't miss it, and went back to listen to April's Biofuels podcast as well. Either I'm holding onto an archaic Farm Bill belief or I've got a nominee for the "underhyped issues" list. Please someone update my priors:
My understanding was that a big part (in overall climate impact if not dollars) of the farm bill is the subsidy for ethanol, this is talked about as a thing that exists in the biofuels conversation from April but not mentioned was where it lives in our appropriations and policy world. This conversation about the farm bill concentrated on food grown for food and not all the other stuff that sits inside a longstanding appropriation like the Farm Bill. That's probably a deliberate choice since between Peter and Dan they understand this area and the collection of all the other stuff that's wrong with the world is a big big enough topic to overshadow the Food implications of Farm Bill policy (nominally the point of this conversation). I did expect some mention of this issue, if it is the big deal I think it is. This missing mention makes the food focus of the conversation here land like evasion of big issues - we'll talk about food issues because we can make a change here that many people will think is common sense and unambiguously good while that intractable problem with the rest of the farm bill we'll just pretend there isn't anything we can do about. Like justifying anything you wanted in the 90s with an utterance of "for the children, " the food focus moves attention away from deeper problems with the farm bill. It provides reasons to get to yes, despite anything else that might be lurking in the bill. Sometimes the best policy is the policy we agree not to make; sometimes preserving that small glimmer of good in a wider ill is to be avoided.
Why do I think the ethanol subsidy a big deal? It drives land use in a particularly inefficient way (food for fuel) throughout the US, but also drives land use change in other countries (e.g. Brazil), and tariff evasion around the world (splash and dash in US ports to send non-compliant origin fossil fuels to Europe as an engineered product). Land use change from plantation farming for fuels comes from an entrenched and foolish US policy that undermines our own food and energy security - in the guise of a Farm Bill. This is, as I understand it, a big motivator for deforestation in the tropics - that sugar cane and palm oil isn't being grown for food and we're the ones waving that biofuels flag and using the Farm Bill to fund it. And while the relatively small subsidy in the US doesn't motivate as much land conversion, it carries further overseas both directly and through financial cleverness in being able to pick and choose how your product is classified/regulated/taxed in international markets.
If I've got that all wrong, I'd love to improve my understanding here.
Great pod. Recent studies show seaweed added to feed can reduce methane in cattle by 90%. Your guest hinted at the benefits of additives but this seems more promising.
Love to hear a pod on carbon sequester though seaweed farming.
David if you're going to delve into this. I would suggest you talk with the National Audubon Society and their successes with animal grazing and restoring wildlife.
Great pod. The talk about lagoons of animal waste made me think you ought to do a pod about Vanguard Renewables. They build digesters on farms to convert animal and food waste into renewable natural gas and electricity. https://www.vanguardrenewables.com
Volatilization of pesticides (including herbicides) and movement of pesticides into field tiles and ag drainage ditches gets little attention and very little monitoring. In the Midwest we are seeing damage to trees and other plants (lethal and not immediately lethal) and incredible loose of insect diversity - both terrestrial and aquatic insects. Perhaps not a very direct cause of climate change, but very likely a "follow-on" issue through loss of biodiversity in the soil, water, and air.
Another disappointing anti-beef tirade on this podcast.
Contrary to the overall impression left by this podcast, 99% of what a US beef cow consumes over its life is not edible by humans. Globally, that figure is 92%. 86% of what all livestock eat is not human edible. These stats are from the UN Food and Agriculture Organization research:
This is not to say that improvements can not be made. Mandating that CAFO manure lagoons be abolished and the manure instead be incorporated into soil would be helpful. Optimizing grassland grazing could sequester many more times carbon than a mature forest per acre.
What I wish Dave, or some interviewer, would ask about from those who've analysed the carbon costs of beef, is how much credit Buffalo Bill Cody should get for shooting 65 million buffalo.
When I looked it up a dozen-odd years ago, the "American National Herd" was bout 105M cows. But they are "half grown" on average, since we killed them the month they are full-grown.
And full-grown is 888 lb these days, in contrast to 1800 for a female bison, over 2000 for a male, and 85% of the average herd was adults. So, it seemed to me that the ungulate-tonnage supported by the Great American Plains is about the same now as when Cody shot his first.
How much methane did they use to put out, when everything was in balance? I think we get that in the 'credit' column.
The EPA number you cite above includes only emissions from enteric fermentation and manure. The podcast noted how this isn't accounting for all emissions related to beef consumption. A holistic accounting includes all the emissions associated with animal feed, transportation, processing, food waste, and the counterfactual of the land being used to sequester carbon instead of being used for grazing.
So you want to compare the full lifecycle emissions of animal food production with other sources of emissions like transportation where there's no full lifecycle analysis?
THANK YOU for covering this topic, and especially for the clear explanation of the need to account for climate emissions and lost future natural sequestration capacity due to land use conversion. I also came from the energy side of climate mitigation, and ran across land use impacts when trying to grasp the climate emissions of biofuels. WA state agencies don’t have this on their radar (I’ve tried over the years to bring it up, unsuccessfully). Now I’m retired, and continue to see state agencies ignore lost natural carbon sequestration capacity in forestry, agriculture, and land use planning in general. Biodiversity loss due to land use is also critical and generally not recognized as an existential problem. THANKS for breaking across the siloed categories of energy and agriculture, and the shallow thinking that is making us do such dumb stuff! I will be sharing this episode.
As a retired MD now raising grass-fed livestock, a climate activist and in recent years a keen student of methane, I read with great interest the CH4 comments on the Farm Bill podcast. Some I agreed completely with, some not.
Dave, methane deserves its own episode of Volts, though it may seem far afield from electrification.
Future management of human-influenced methane emissions has enormous and unique potential to turn a corner on rising surface temps, because, as Roger says, methane is a “flow gas.” IF AND ONLY IF total human-influenced annual CH4 emissions were to end their rising trend, the conventional “equivalence” of CH4 to CO2 on a stated time horizon like a GWP100 would be recognized as without meaning. In a thought experiment, if these emissions were to level off, about ten years later humans would see CH4 no longer adding annually to radiative forcing, though it would still be contributing to it. If these emissions lessened over time, thought experimenters would see radiative forcing (and related heating-up) decline, even if hundreds of megatons of CH4 emissions would be seem equivalent by GWP20 or 100 (I prefer 20) to many Gt CO2.
Roger mentions GWP* (GWP star) as a novel metric proposed by an international group. GWP* is not related, however, to any “CO2 component” of CH4. It can’t be applied to one source of methane and not another in the same earth system. GWP* is a BRILLIANT TEACHING DEVICE that shows humankind how much leverage we theoretically have with CH4 on rising temps, while we have almost none on CO2’s effect until emissions are truly nil.
GWP* will speak truth, BUT ONLY ON THE ABOVE CONDITION, that CH4 emissions are unchanged or falling year to year. It is a hypothetical. GWP* is as meaningless in a system of rising CH4 emissions as would be GWP in a world of declining releases. In the tweeted citation the key word is “constant.”
Planned and unplanned CH4 emissions from the fossil fuel industry cannot be brought to zero. IMO the least harmful way to level off human-influenced methane releases is to stop increasing the world’s annual withdrawal of natural gas as we increase renewables, conservation, storage and innovative transmission.
To those who also won't listen to podcasts on monopolistic techbro web services, and want to download the MP3, note that if you open the "RSS feed" link as a text file, it contains the URL to the MP3 file, then you can download.
Thank you for doing this podcast David. This is such a fascinating area. The earth will not make it without healthy farming as part of the solution. People who don’t feel they can do anything to help climate change can make simple dietary changes that can make a difference (no meat for 2 meals a week.) SPCA had a program of meatless Mondays but I haven’t seen anything about that recently.
Excellent podcast! This is such an important topic, one disregarded most of the time. Thank you for stepping up to the job of informing countrymen about the Farm Bill.
And this figure is a bit of an overestimate, considering that livestock methane emissions are a biogas and should not be measured the same way as fossil methane.
Here's a blurb from Farming for Our Future (the guest's book):
"...This is because the most widely-used emissions figures comes from the Environmental Protection Agency greenhouse gas inventory, which estimates that agriculture is responsible for only about 10% of the country’s total GHG emissions. Yet changes to agricultural and food policies will have a far bigger impact than this figure suggests.
EPA’s inventory places many agricultural activities, such as on-farm energy usage, annual land use conversion, and the production of agricultural inputs, in other inventory sectors, but changes to agricultural practices will help reduce these emissions as well. Moreover, since agriculture occupies over one billion acres in the US and over 60% of the contiguous land mass, policy changes that create incentives or mandates that allow more land to sequester more carbon as it did prior to land conversion are both urgently needed and can have a big impact.
In addition, using a method for calculating the impact of methane over 20 years — consistent with the need for short-term action and current near-term policy discussions instead of the 100-year impact as in EPA’s inventory, more than doubles the impact of agriculture’s emissions – and also doubles the impact of reductions. (Recent research also indicates that EPA’s models are often overly conservative when compared to actual measurements.) Accounting for all these adjustments to the standard brings the total GHG emissions attributable to the agricultural sector to about one-third of all U.S. emissions. A better understanding of the significance of agriculture GHG emissions makes clear that the country cannot reach its climate goals unless we address the agriculture sector and demonstrates the tremendous potential impact of food policy reform."
This is literally the conversation from the 20 minute to 23 minute mark, where the speaker directly addresses the lifecycle boundary choices the EPA made here and how he... doesn't agree with those choices.
My understanding is that as methane breaks down in the atmosphere, the end product is carbon dioxide. So when all the methane from a given ton of emissions has broken down, the resulting carbon dioxide would either be drawn from the atmosphere through recent photosynthesis (biomethane) or derived from fossil carbon that has been sequestered geologically for a long time (natural gas). Thus isn't the end-state net atmospheric CO2 different between biomethane and fossil methane, even if the methane itself behaves the same once emitted? And wouldn't this result in a wider divergence in GWP between fossil and bio methane the longer the time horizon considered?
Livestock methane has no CO2 component, which is the major driver of global warming. This is not just some pet theory of mine - the IPCC has recognized this difference and is recommending using the GWP* metric .
This is all based on using the GWP20 or the GWP100 window for measuring methane warming potential, which is incredibly inaccurate since CO last for tens of thousands of years, not 20 or 100 years.
When you say livestock methane has "no CO2 component", are you referring to the same thing I asked about above? That is, the carbon in the CO2 breakdown product of biomethane has a recent atmospheric source, whereas the CO2 from fossil methane breakdown was sequestered geologically until we pulled it out?
Also, can you point to an IPCC source on the different GWP metrics? I'm curious how different they are.
I've seen the paper on this in the last 3 months, I'll dig it out (search has become shit now that we have AI helping). The distinction is real, but we're talking about a slightly less bad pathway and not a good pathway.
So much of methane emissions is known bad data, all estimates are terrible right now. Better to look at real effects of the chemistry rather than try to weigh the global interactions as one. Tundra and Bog-loss will dwarf everything, but that doesn't mean this human choice isn't a problem we should meekly accept as inevitable.
The operative exchange is literally this conversation:
Q) Are you counting the biological origin of ag methane and it is a cycle?
A) Yes, here is the chart of the GWP for 8 GHGs, with the two methane origins broken out for clarity.
Since I can't paste the image, the GWP100 of biogenic vs. fossil methane is 29.8 vs. 27.2 (both +-11).
If someone is reporting 3 or 4x emissions differences they are looking at a lifecycle boundary - one party counting only burps and the other including land use, waste, water, etc. or taking different data sources for the emissions quantities (industry vs. 3rd party). As satellite sensing of methane expands a lot of bad assumptions will start being peeled away.
I don't have the most recent IPCC report, but I can show you a snippet of the previous proposed guideline re GWP*. IIRC, they say GWP100 overestimates cow methane by a factor of 3x to 4x (And IIRC, they are not even talking about the CO2 difference, merely the fact that CH4 is a flow source ( ie, is removed about as fast as it is produced.) The fact that CH4 levels are increasing has little to do with livestock, but with increased emissions from permafrost, wetlands and industrial leakage:
Methane is around 85x more potent in terms of absorbing solar radiation (heating the planet). It dissipates more quickly, sure, but as far as tackling the overall problem, methane is a huge lever that, if drastically reduced, can buy us time in reducing the other GHGs (CO2 first among them).
CH4 becomes CO2 and water after 10 years in the atmosphere. That CO2 lasts for 10,000 to 200,000 years. Your "85x more potent" figure is based only on the first 20 years of that process, so it misses 99% of the true Global Warming Potential (GWP) of methane - which is due to its CO2 component.
But cow methane does not have a CO2 component, because it is made from CO2 just stripped out of the air by the plant the cow ate.
The IPCC is now recommending that cow methane and fossil methane use different metrics because of this. (See GWP*).
90% of crop agriculture biomass is not the fruit - it is the leaves and stalks. This (plus huge amounts of grass) is what makes up a large part of cow food. We can either feed it to cows and make food, or let it rot away to CO2 and methane.
Which is a point not mentioned by the anti-beef brigade.
This fast breakdown to CO₂ and H₂O isn't a good thing. Water is the mechanism whereby the atmosphere holds more energy, it holds the warming of atmospheric warming. The methane itself is a precursor to Ozone in its decomposition path, and the CO₂ decomp just gets you back to the known not great CO₂ emission.
That the source of the methane is biomass vs. fossil means we're in the same time-cycle for the circulating chemicals. That's the good part. The reason this isn't a net zero system is that the non-grazing pathway leads to significant carbon storage in soils, far soil less erosion, watershed fouling, and ecosystem loss.
Good point about the source of the O2 coming from plant matter that ultimately sequestered CO2 in the first place. That said the point I was trying to make is the short term gains that can be gained from addressing methane in all forms wherever possible methane emission reduction significantly help over the short term And we need all the help we can get right now.
But the world is not going vegan anytime soon, and even if it did, we probably could not even grow enough new vegetables to make it happen. ( In the US, livestock provide 23% of our calories and 63% of our protein). And the more vegetables we raise, the more GHG emissions we would have. It is very close to being a wash overall, except that many millions of 3rd world people would die without their livestock. And 70% to 80% of global livestock emissions are from the developing world. We are kinda stuck with that.
Which is why efforts are being made to reduce the waste/leakage emissions from the natural gas industry. Also good results from capturing manure methane as fuel - much better to burn it than let it escape or even incorporate it into soils.
The fact is that all this hoopla about livestock, manure, etc is kinda crazy. The Earth's carbon cycle dealt with all the flora and fauna on the planet just fine - CO2 was in pretty stable condition for millions of years. It was not until we started introducing extraneous carbon via fossil fuel burning that CO2 levels started their climb.
The burning of fossil fuels is not just the culprit - it is also the low-hanging fruit. If we can just electrify everything fast enough, we should be fine. Big if.
I listened to this twice to make sure I didn't miss it, and went back to listen to April's Biofuels podcast as well. Either I'm holding onto an archaic Farm Bill belief or I've got a nominee for the "underhyped issues" list. Please someone update my priors:
My understanding was that a big part (in overall climate impact if not dollars) of the farm bill is the subsidy for ethanol, this is talked about as a thing that exists in the biofuels conversation from April but not mentioned was where it lives in our appropriations and policy world. This conversation about the farm bill concentrated on food grown for food and not all the other stuff that sits inside a longstanding appropriation like the Farm Bill. That's probably a deliberate choice since between Peter and Dan they understand this area and the collection of all the other stuff that's wrong with the world is a big big enough topic to overshadow the Food implications of Farm Bill policy (nominally the point of this conversation). I did expect some mention of this issue, if it is the big deal I think it is. This missing mention makes the food focus of the conversation here land like evasion of big issues - we'll talk about food issues because we can make a change here that many people will think is common sense and unambiguously good while that intractable problem with the rest of the farm bill we'll just pretend there isn't anything we can do about. Like justifying anything you wanted in the 90s with an utterance of "for the children, " the food focus moves attention away from deeper problems with the farm bill. It provides reasons to get to yes, despite anything else that might be lurking in the bill. Sometimes the best policy is the policy we agree not to make; sometimes preserving that small glimmer of good in a wider ill is to be avoided.
Why do I think the ethanol subsidy a big deal? It drives land use in a particularly inefficient way (food for fuel) throughout the US, but also drives land use change in other countries (e.g. Brazil), and tariff evasion around the world (splash and dash in US ports to send non-compliant origin fossil fuels to Europe as an engineered product). Land use change from plantation farming for fuels comes from an entrenched and foolish US policy that undermines our own food and energy security - in the guise of a Farm Bill. This is, as I understand it, a big motivator for deforestation in the tropics - that sugar cane and palm oil isn't being grown for food and we're the ones waving that biofuels flag and using the Farm Bill to fund it. And while the relatively small subsidy in the US doesn't motivate as much land conversion, it carries further overseas both directly and through financial cleverness in being able to pick and choose how your product is classified/regulated/taxed in international markets.
If I've got that all wrong, I'd love to improve my understanding here.
Great pod. Recent studies show seaweed added to feed can reduce methane in cattle by 90%. Your guest hinted at the benefits of additives but this seems more promising.
Love to hear a pod on carbon sequester though seaweed farming.
Thanks for all your work.
Steve
David if you're going to delve into this. I would suggest you talk with the National Audubon Society and their successes with animal grazing and restoring wildlife.
Great pod. The talk about lagoons of animal waste made me think you ought to do a pod about Vanguard Renewables. They build digesters on farms to convert animal and food waste into renewable natural gas and electricity. https://www.vanguardrenewables.com
Volatilization of pesticides (including herbicides) and movement of pesticides into field tiles and ag drainage ditches gets little attention and very little monitoring. In the Midwest we are seeing damage to trees and other plants (lethal and not immediately lethal) and incredible loose of insect diversity - both terrestrial and aquatic insects. Perhaps not a very direct cause of climate change, but very likely a "follow-on" issue through loss of biodiversity in the soil, water, and air.
Loved this! And, for the record, no anti-beef tirade ever disappoints.
Another disappointing anti-beef tirade on this podcast.
Contrary to the overall impression left by this podcast, 99% of what a US beef cow consumes over its life is not edible by humans. Globally, that figure is 92%. 86% of what all livestock eat is not human edible. These stats are from the UN Food and Agriculture Organization research:
https://www.cgiar.org/news-events/news/fao-sets-the-record-straight-86-of-livestock-feed-is-inedible-by-humans
The total GHG emissions of US beef cattle is less than 2% of US total GHG emissions according to the EPA:
https://www.flickr.com/photos/96198796@N05/33335275208/in/album-72157714202939482/
This is not to say that improvements can not be made. Mandating that CAFO manure lagoons be abolished and the manure instead be incorporated into soil would be helpful. Optimizing grassland grazing could sequester many more times carbon than a mature forest per acre.
What I wish Dave, or some interviewer, would ask about from those who've analysed the carbon costs of beef, is how much credit Buffalo Bill Cody should get for shooting 65 million buffalo.
When I looked it up a dozen-odd years ago, the "American National Herd" was bout 105M cows. But they are "half grown" on average, since we killed them the month they are full-grown.
And full-grown is 888 lb these days, in contrast to 1800 for a female bison, over 2000 for a male, and 85% of the average herd was adults. So, it seemed to me that the ungulate-tonnage supported by the Great American Plains is about the same now as when Cody shot his first.
How much methane did they use to put out, when everything was in balance? I think we get that in the 'credit' column.
The EPA number you cite above includes only emissions from enteric fermentation and manure. The podcast noted how this isn't accounting for all emissions related to beef consumption. A holistic accounting includes all the emissions associated with animal feed, transportation, processing, food waste, and the counterfactual of the land being used to sequester carbon instead of being used for grazing.
So you want to compare the full lifecycle emissions of animal food production with other sources of emissions like transportation where there's no full lifecycle analysis?
THANK YOU for covering this topic, and especially for the clear explanation of the need to account for climate emissions and lost future natural sequestration capacity due to land use conversion. I also came from the energy side of climate mitigation, and ran across land use impacts when trying to grasp the climate emissions of biofuels. WA state agencies don’t have this on their radar (I’ve tried over the years to bring it up, unsuccessfully). Now I’m retired, and continue to see state agencies ignore lost natural carbon sequestration capacity in forestry, agriculture, and land use planning in general. Biodiversity loss due to land use is also critical and generally not recognized as an existential problem. THANKS for breaking across the siloed categories of energy and agriculture, and the shallow thinking that is making us do such dumb stuff! I will be sharing this episode.
We desperately need to reduce greenhouse gases ASAP.
As a retired MD now raising grass-fed livestock, a climate activist and in recent years a keen student of methane, I read with great interest the CH4 comments on the Farm Bill podcast. Some I agreed completely with, some not.
Dave, methane deserves its own episode of Volts, though it may seem far afield from electrification.
Future management of human-influenced methane emissions has enormous and unique potential to turn a corner on rising surface temps, because, as Roger says, methane is a “flow gas.” IF AND ONLY IF total human-influenced annual CH4 emissions were to end their rising trend, the conventional “equivalence” of CH4 to CO2 on a stated time horizon like a GWP100 would be recognized as without meaning. In a thought experiment, if these emissions were to level off, about ten years later humans would see CH4 no longer adding annually to radiative forcing, though it would still be contributing to it. If these emissions lessened over time, thought experimenters would see radiative forcing (and related heating-up) decline, even if hundreds of megatons of CH4 emissions would be seem equivalent by GWP20 or 100 (I prefer 20) to many Gt CO2.
Roger mentions GWP* (GWP star) as a novel metric proposed by an international group. GWP* is not related, however, to any “CO2 component” of CH4. It can’t be applied to one source of methane and not another in the same earth system. GWP* is a BRILLIANT TEACHING DEVICE that shows humankind how much leverage we theoretically have with CH4 on rising temps, while we have almost none on CO2’s effect until emissions are truly nil.
GWP* will speak truth, BUT ONLY ON THE ABOVE CONDITION, that CH4 emissions are unchanged or falling year to year. It is a hypothetical. GWP* is as meaningless in a system of rising CH4 emissions as would be GWP in a world of declining releases. In the tweeted citation the key word is “constant.”
Planned and unplanned CH4 emissions from the fossil fuel industry cannot be brought to zero. IMO the least harmful way to level off human-influenced methane releases is to stop increasing the world’s annual withdrawal of natural gas as we increase renewables, conservation, storage and innovative transmission.
Cheers
To those who also won't listen to podcasts on monopolistic techbro web services, and want to download the MP3, note that if you open the "RSS feed" link as a text file, it contains the URL to the MP3 file, then you can download.
https://api.substack.com/feed/podcast/139291578/2a581218098734c490607fb001e3ed59.mp3
Fortunate, since I'd have to stop subscribing if I couldn't download an MP3.
Thank you for doing this podcast David. This is such a fascinating area. The earth will not make it without healthy farming as part of the solution. People who don’t feel they can do anything to help climate change can make simple dietary changes that can make a difference (no meat for 2 meals a week.) SPCA had a program of meatless Mondays but I haven’t seen anything about that recently.
Excellent podcast! This is such an important topic, one disregarded most of the time. Thank you for stepping up to the job of informing countrymen about the Farm Bill.
The EPA tells us that agriculture is only 10% of US annual GHG emissions. See:
https://www.flickr.com/photos/96198796@N05/47210689941/in/album-72157705569308771/
And this figure is a bit of an overestimate, considering that livestock methane emissions are a biogas and should not be measured the same way as fossil methane.
How does the speaker come up with 30%?
Here's a blurb from Farming for Our Future (the guest's book):
"...This is because the most widely-used emissions figures comes from the Environmental Protection Agency greenhouse gas inventory, which estimates that agriculture is responsible for only about 10% of the country’s total GHG emissions. Yet changes to agricultural and food policies will have a far bigger impact than this figure suggests.
EPA’s inventory places many agricultural activities, such as on-farm energy usage, annual land use conversion, and the production of agricultural inputs, in other inventory sectors, but changes to agricultural practices will help reduce these emissions as well. Moreover, since agriculture occupies over one billion acres in the US and over 60% of the contiguous land mass, policy changes that create incentives or mandates that allow more land to sequester more carbon as it did prior to land conversion are both urgently needed and can have a big impact.
In addition, using a method for calculating the impact of methane over 20 years — consistent with the need for short-term action and current near-term policy discussions instead of the 100-year impact as in EPA’s inventory, more than doubles the impact of agriculture’s emissions – and also doubles the impact of reductions. (Recent research also indicates that EPA’s models are often overly conservative when compared to actual measurements.) Accounting for all these adjustments to the standard brings the total GHG emissions attributable to the agricultural sector to about one-third of all U.S. emissions. A better understanding of the significance of agriculture GHG emissions makes clear that the country cannot reach its climate goals unless we address the agriculture sector and demonstrates the tremendous potential impact of food policy reform."
This is literally the conversation from the 20 minute to 23 minute mark, where the speaker directly addresses the lifecycle boundary choices the EPA made here and how he... doesn't agree with those choices.
Sorry, methane is methane, whatever the source: animal, seafloor venting, thawing nodules, fugitive pipeline leaks, oil-well flaring, refineries, plant decay, inefficient combustion, etc.
My understanding is that as methane breaks down in the atmosphere, the end product is carbon dioxide. So when all the methane from a given ton of emissions has broken down, the resulting carbon dioxide would either be drawn from the atmosphere through recent photosynthesis (biomethane) or derived from fossil carbon that has been sequestered geologically for a long time (natural gas). Thus isn't the end-state net atmospheric CO2 different between biomethane and fossil methane, even if the methane itself behaves the same once emitted? And wouldn't this result in a wider divergence in GWP between fossil and bio methane the longer the time horizon considered?
Methane most definitely is NOT methane.
Livestock methane has no CO2 component, which is the major driver of global warming. This is not just some pet theory of mine - the IPCC has recognized this difference and is recommending using the GWP* metric .
This is all based on using the GWP20 or the GWP100 window for measuring methane warming potential, which is incredibly inaccurate since CO last for tens of thousands of years, not 20 or 100 years.
When you say livestock methane has "no CO2 component", are you referring to the same thing I asked about above? That is, the carbon in the CO2 breakdown product of biomethane has a recent atmospheric source, whereas the CO2 from fossil methane breakdown was sequestered geologically until we pulled it out?
Also, can you point to an IPCC source on the different GWP metrics? I'm curious how different they are.
I've seen the paper on this in the last 3 months, I'll dig it out (search has become shit now that we have AI helping). The distinction is real, but we're talking about a slightly less bad pathway and not a good pathway.
So much of methane emissions is known bad data, all estimates are terrible right now. Better to look at real effects of the chemistry rather than try to weigh the global interactions as one. Tundra and Bog-loss will dwarf everything, but that doesn't mean this human choice isn't a problem we should meekly accept as inevitable.
By 3 months I meant 6. It was Zeke Hausfather's [https://twitter.com/hausfath/status/1653977053157527552] regular reminder about OurWorldInData's Environmental Impacts of Food (2018 data) [https://ourworldindata.org/environmental-impacts-of-food].
The operative exchange is literally this conversation:
Q) Are you counting the biological origin of ag methane and it is a cycle?
A) Yes, here is the chart of the GWP for 8 GHGs, with the two methane origins broken out for clarity.
Since I can't paste the image, the GWP100 of biogenic vs. fossil methane is 29.8 vs. 27.2 (both +-11).
If someone is reporting 3 or 4x emissions differences they are looking at a lifecycle boundary - one party counting only burps and the other including land use, waste, water, etc. or taking different data sources for the emissions quantities (industry vs. 3rd party). As satellite sensing of methane expands a lot of bad assumptions will start being peeled away.
Yes - you got it right.
I don't have the most recent IPCC report, but I can show you a snippet of the previous proposed guideline re GWP*. IIRC, they say GWP100 overestimates cow methane by a factor of 3x to 4x (And IIRC, they are not even talking about the CO2 difference, merely the fact that CH4 is a flow source ( ie, is removed about as fast as it is produced.) The fact that CH4 levels are increasing has little to do with livestock, but with increased emissions from permafrost, wetlands and industrial leakage:
https://www.flickr.com/photos/96198796@N05/51596001579/in/album-72157714202939482/
Methane is around 85x more potent in terms of absorbing solar radiation (heating the planet). It dissipates more quickly, sure, but as far as tackling the overall problem, methane is a huge lever that, if drastically reduced, can buy us time in reducing the other GHGs (CO2 first among them).
CH4 becomes CO2 and water after 10 years in the atmosphere. That CO2 lasts for 10,000 to 200,000 years. Your "85x more potent" figure is based only on the first 20 years of that process, so it misses 99% of the true Global Warming Potential (GWP) of methane - which is due to its CO2 component.
But cow methane does not have a CO2 component, because it is made from CO2 just stripped out of the air by the plant the cow ate.
The IPCC is now recommending that cow methane and fossil methane use different metrics because of this. (See GWP*).
90% of crop agriculture biomass is not the fruit - it is the leaves and stalks. This (plus huge amounts of grass) is what makes up a large part of cow food. We can either feed it to cows and make food, or let it rot away to CO2 and methane.
Which is a point not mentioned by the anti-beef brigade.
This fast breakdown to CO₂ and H₂O isn't a good thing. Water is the mechanism whereby the atmosphere holds more energy, it holds the warming of atmospheric warming. The methane itself is a precursor to Ozone in its decomposition path, and the CO₂ decomp just gets you back to the known not great CO₂ emission.
That the source of the methane is biomass vs. fossil means we're in the same time-cycle for the circulating chemicals. That's the good part. The reason this isn't a net zero system is that the non-grazing pathway leads to significant carbon storage in soils, far soil less erosion, watershed fouling, and ecosystem loss.
Good point about the source of the O2 coming from plant matter that ultimately sequestered CO2 in the first place. That said the point I was trying to make is the short term gains that can be gained from addressing methane in all forms wherever possible methane emission reduction significantly help over the short term And we need all the help we can get right now.
Agreed.
But the world is not going vegan anytime soon, and even if it did, we probably could not even grow enough new vegetables to make it happen. ( In the US, livestock provide 23% of our calories and 63% of our protein). And the more vegetables we raise, the more GHG emissions we would have. It is very close to being a wash overall, except that many millions of 3rd world people would die without their livestock. And 70% to 80% of global livestock emissions are from the developing world. We are kinda stuck with that.
Which is why efforts are being made to reduce the waste/leakage emissions from the natural gas industry. Also good results from capturing manure methane as fuel - much better to burn it than let it escape or even incorporate it into soils.
The fact is that all this hoopla about livestock, manure, etc is kinda crazy. The Earth's carbon cycle dealt with all the flora and fauna on the planet just fine - CO2 was in pretty stable condition for millions of years. It was not until we started introducing extraneous carbon via fossil fuel burning that CO2 levels started their climb.
The burning of fossil fuels is not just the culprit - it is also the low-hanging fruit. If we can just electrify everything fast enough, we should be fine. Big if.