New Study: Apparently Home Gardening is Bad for the Environment

[rossomendblot]

They had some stunning emissions reported for compost, which really surprised me. Composting can be anaerobic if it's not turned or structured properly, and they seemed to be saying most of the composting was not properly done. But I didn't manage to get the actual data sheet to see how that data was collected or what the statement was based on. Did the citizen scientist volunteers actually measure emissions from the gardens' compost piles? IDK .
They did not estimate a neutralizing value for carbon sequestered by adding all that compost to the soil - which is ludicrous really, although they excused due to difficulty of measuring or estimating that. It can be estimated, just as well as other things were estimated IMO. So that's not good enough if you're in the business of figuring the carbon footprint, and comparing gardens that use mainly or entirely compost to conventional agriculture which is using entirely chemical ferts and sequestering no carbon at all.
But as I said before, every study has its limits and flaws, and we have to expect that. Tk goodness for access to the full text though!

They mention this limitation at the end of the study under 'Future Research':

"Better data are needed on carbon fluxes of composting at UA sites. We found composting contributes substantially to the carbon footprint of UA (Supplementary Table 4). Despite this, little is known about differences in GHGs from various composting techniques50,51. Furthermore, the high application rates of compost in UA probably raises additional questions. For example, the effects of long-term composting on N2O emissions are unclear, and strategic management of application scheduling and fertilizer combinations may be required to minimize emissions52,53. How the repeated use of compost affects soil carbon sequestration in raised beds is also unclear, although existing evidence suggests that compost-dependent systems may sequester substantial carbon54,55. Both topics warrant further study."

They have composting as the number one source contributor to climate change for 22 out of the 73 sites. I can't find how they've come to that result, though.

They also say "In fact, we estimate that careful compost management could cut GHGs by 39.4% on sites that use small-scale composting."

[bower]

@rossomendblot indeed. I read this paragraph and tried to bring up Supp Table 4, but didn't manage to access it - granted, late at night and I may not be the most adept at navigating.

IMHO it is simply wrong for them to list composting as a contributor to carbon footprint in these garden sites without also estimating some value for the compost use itself. The '4 per mille' movement for example, has produced some kind of estimate of the value of increasing farm soil carbon storage by 0.4 percent per year, which iirc amounts to spreading a 4mm layer of compost over your area. (I need to check that figure but I believe that's what it was.)
Here's another estimate:
"Just a 1% increase in soil organic matter (about 20 tons of compost per acre or a 1/4-inch application depth) can store 10 tons of carbon per acre."
https://mcgillcompost.com/resources/can ... n-storage/
I know there is some dithering about soil disturbance and carbon losses but still "..Even annually tilled acres can offer C sequestration if that carbon can find a pathway to deeper soils below the plow layer." There may not be an exact science when it comes to the storage in a forked raised bed vs farm spreading and/or massively tilled and chemically fertilized acres. But there is no question that proper composting (keeping it aerobic) and adding compost to garden soils has a negative carbon footprint potential.
Ignoring the fact that conventional farming with manufactured ferts is releasing carbon and degrading soils instead of sequestering, is also deeply problematic to my mind, when comparing the footprints of one and the other. The authors seem to have missed the point altogether that food production has an enormous potential to sequester carbon through compost.

[karstopography]

There needs to be a study of how much server farm energy and other energy expenditures are necessary to conduct and disseminate these studies.

https://www.energy.gov/eere/buildings/d ... %20centers.

Data centers account for 2% of electricity useage in US. But, I’m sure there are additional inputs of energy to conduct these studies.

Actually, I’m fine with trying to get a handle on this information and an understanding about the actual data about relevant emissions from gardens, composting and such. I’m more concerned about what happens, if anything, on the policy level as it relates to all this composting and small scale gardening activity.

Do I think there are there powerful people out there that would be willing to or have the audacity, interest or inclination to make the necessary policy changes, laws and use political influence, subterfuge to meaningfully restrict or prohibit private gardening activities? You bet I do.

[GoDawgs]

Do I think there are there powerful people out there that would be willing to or have the audacity, interest or inclination to make the necessary policy changes, laws and use political influence, subterfuge to meaningfully restrict or prohibit private gardening activities? You bet I do.

Amen to dat, Brutha!

[karstopography]

Some of this stuff the powerful do is just because they can. It’s like why climb Mt. Everest? There’s nothing up there other than a view. People do it because they can, it’s there, it’s something to brag about.

It’s the same with the powerful, they sometimes just want to do malicious policy stuff just to put that feather in their cap, great cocktail party talk you know, and some people make policy change to be ahead of the curve. If you already know what’s coming, then you can put resources i.e, money into areas that take advantage of the upcoming changes.

Jack with policy and make some real jack!

[bower]

To be fair to the study authors, their take away message was not to 'restrict or prohibit' private or community gardening activities.

Their policy related conclusion was that the govs need to ensure developers don't get permits to bulldoze community gardens for their real estate projects, and that municipal govs need to facilitate the movement of materials from the building (and tearing down) industry to repurpose for urban agriculture.
The relationship with real estate developers is really the problem they highlighted, for urban agriculture. I suppose those are the same 'powerful people' who would be motivated to stop UA or restrict it, where it interferes with their intended land use.

The claims that composting isn't done properly on a small scale are not clearly supported. I would agree that if there's a problem then providing some good instruction on how to do it is the key - we all want good healthy compost if we're doing it. They also suggest that govs could take responsibility and make compost on a large scale. I'm not in favor of that policy for my own area, and I don't think it's a perfect substitute for making your own compost and knowing exactly what went into it. Right?!

Government policy in my area has been to encourage (nay, beg!) private citizens to all compost their household waste on their private property. Government here does not want any responsibility for collecting, composting, and distributing compost. They just want food waste kept out of the landfill, where we know already it is decomposing anaerobically and emitting methane.
So the whole point of policy at least in my area, is to reduce that landfill methane scenario by home composting. Much cheaper than building facilities for 'officially made' compost. And TBH it's hard to imagine that the gardens in the study were in any way as bad as just sending waste to landfill.
IDK, are there wierd anti-composting policies anywhere else?
Cities with high rises, I suppose, don't have place to do that or garden either.

[Wildcat82]

@rossomendblot indeed. I read this paragraph and tried to bring up Supp Table 4, but didn't manage to access it - granted, late at night and I may not be the most adept at navigating.

IMHO it is simply wrong for them to list composting as a contributor to carbon footprint in these garden sites without also estimating some value for the compost use itself. The '4 per mille' movement for example, has produced some kind of estimate of the value of increasing farm soil carbon storage by 0.4 percent per year, which iirc amounts to spreading a 4mm layer of compost over your area. (I need to check that figure but I believe that's what it was.)
Here's another estimate:
"Just a 1% increase in soil organic matter (about 20 tons of compost per acre or a 1/4-inch application depth) can store 10 tons of carbon per acre."
https://mcgillcompost.com/resources/can ... n-storage/
I know there is some dithering about soil disturbance and carbon losses but still "..Even annually tilled acres can offer C sequestration if that carbon can find a pathway to deeper soils below the plow layer." There may not be an exact science when it comes to the storage in a forked raised bed vs farm spreading and/or massively tilled and chemically fertilized acres. But there is no question that proper composting (keeping it aerobic) and adding compost to garden soils has a negative carbon footprint potential.
Ignoring the fact that conventional farming with manufactured ferts is releasing carbon and degrading soils instead of sequestering, is also deeply problematic to my mind, when comparing the footprints of one and the other. The authors seem to have missed the point altogether that food production has an enormous potential to sequester carbon through compost.

You are correct in your analysis. However, the people doing this study at the University of Michigan don't care because they aren't doing "science." They are doing propaganda dressed up up as a scientific study. I've worked with these kind of people at universities, the EPA, and other regulatory agencies. Researchers pump out useless crap studies all the time simply because it's easy to get funding for these types of studies and the regulators love these studies because they can use them as an excuse to pass more onerous regulations. That's how they get a bigger budget. Which spurs more funding for crap studies. It's a viscous self perpetuating cycle.

[Wildcat82]

Some of this stuff the powerful do is just because they can. It’s like why climb Mt. Everest? There’s nothing up there other than a view. People do it because they can, it’s there, it’s something to brag about.

It’s the same with the powerful, they sometimes just want to do malicious policy stuff just to put that feather in their cap, great cocktail party talk you know, and some people make policy change to be ahead of the curve. If you already know what’s coming, then you can put resources i.e, money into areas that take advantage of the upcoming changes.

Jack with policy and make some real jack!

I think a lot of the elitists crave power over other people. Stupid uneducated masses need to be lead, guided or coerced into doing what the educated elite believe to the right course of action.

[Wildcat82]

To be fair to the study authors, their take away message was not to 'restrict or prohibit' private or community gardening activities.

Their policy related conclusion was that the govs need to ensure developers don't get permits to bulldoze community gardens for their real estate projects, and that municipal govs need to facilitate the movement of materials from the building (and tearing down) industry to repurpose for urban agriculture.
The relationship with real estate developers is really the problem they highlighted, for urban agriculture. I suppose those are the same 'powerful people' who would be motivated to stop UA or restrict it, where it interferes with their intended land use.

The claims that composting isn't done properly on a small scale are not clearly supported. I would agree that if there's a problem then providing some good instruction on how to do it is the key - we all want good healthy compost if we're doing it. They also suggest that govs could take responsibility and make compost on a large scale. I'm not in favor of that policy for my own area, and I don't think it's a perfect substitute for making your own compost and knowing exactly what went into it. Right?!

Government policy in my area has been to encourage (nay, beg!) private citizens to all compost their household waste on their private property. Government here does not want any responsibility for collecting, composting, and distributing compost. They just want food waste kept out of the landfill, where we know already it is decomposing anaerobically and emitting methane.
So the whole point of policy at least in my area, is to reduce that landfill methane scenario by home composting. Much cheaper than building facilities for 'officially made' compost. And TBH it's hard to imagine that the gardens in the study were in any way as bad as just sending waste to landfill.
IDK, are there wierd anti-composting policies anywhere else?
Cities with high rises, I suppose, don't have place to do that or garden either.

I'm sure somewhere in the US EPA, there is some power hungry/true believer bureaucrat who is proposing the formation of new regulations mandating the "proper" way to compost and grow a small family garden.

[JRinPA]

I'm not understanding how any compost is bad, aerobic or anaerobic.

If a pile is too green, IE anaerobic, then Black Solider Flies lay eggs in it. Those big maggots eat and expel wastes which is fine for growing in. And, many of them get eaten themselves by songbirds. Or your chickens, if you are allowed to have them where you live. The net gain for "Life" is much greater than a huge monoculture field of some grain field that has the crop processed and trucked across the country.

[GoDawgs]

I'm not understanding how any compost is bad, aerobic or anaerobic.

If a pile is too green, IE anaerobic, then Black Solider Flies lay eggs in it. Those big maggots eat and expel wastes which is fine for growing in. And, many of them get eaten themselves by songbirds. Or your chickens, if you are allowed to have them where you live. The net gain for "Life" is much greater than a huge monoculture field of some grain field that has the crop processed and trucked across the country.

Black Soldier flies will compost your pile in a heartbeat! They only live long enough to mate and lay more eggs and don't bother anything. They're a good thing!

BTW, here's a link with lots of composting info, including black soldier flies:
https://permies.com/f/72/composting

[worth1]

Sort of related if you think about research.
I read an article about the B 17 flying fortress.
First mistake, the US didn't have an Air Force in the 30s.
Second mistake he called it a jet.
After that I just stopped reading.
Looked at the person that wrote the article and it was a college student.
Do your research and proof read.

[bower]

I'm not understanding how any compost is bad, aerobic or anaerobic.

If a pile is too green, IE anaerobic, then Black Solider Flies lay eggs in it. Those big maggots eat and expel wastes which is fine for growing in. And, many of them get eaten themselves by songbirds. Or your chickens, if you are allowed to have them where you live. The net gain for "Life" is much greater than a huge monoculture field of some grain field that has the crop processed and trucked across the country.

Another great point - habitat value. Rest asssured, the invertebrates people like Xerces Society will come to the defense of home gardens and scattered habitat, if some monstrous policy 'elite' decides to come for your home compost. They've done their own studies and found how beneficial small plots are for sustaining insect diversity. (Birds too!).

[karstopography]

I don’t see how all the people and the animals necessary to feed all the people currently around gets done without large scale and efficient agriculture, but then horticultural farming, plus composting is a big part of what it is to be human to billions of people.

Science is great to delve into and understand the gaseous emissions that potentially have implications for the climate and where these gases originate. The trouble comes when the policy makers come along and decide to radically alter well entrenched and important economies and ways of doing things without having even close to viable or practical alternatives. In other words, it fine to study and observe that and accurate to say such and such activity emits X amount of methane or CO2 and its also fine to say that these such emissions are an issue based on the current understanding of climate science, but it isn’t fine to make policy that essentially violates and cripplingly confounds the ability to conduct all the essential activities of modern human civilization.

If these policy folks, and I’m not necessarily saying they are, but if they are coming after home barbecue pits, little urban allotment gardens and garden compost piles to solve the projected or real climate problems, then they are not nearly as smart as they think they are or they are tragically misguided or they are just evil totalitarians or all of the above.

[zeuspaul]

Some students and faculty did some limited research into climate change with good intentions. They identified their weaknesses and suggested more research was needed. Maybe they could have done a better job presenting their work.

And now we have conspiracy theories, the elite is coming to take our compost away! Must be funded by George Soros! Do we really believe this so called elite is coming to take our compost away? The elite is also responsible for everything else in the world we don't agree with.

The elite doesn't control me nor do I believe they are coming to take my compost away. Maybe the elite will affect the location of where a compost pile is located or maybe it will be public servants concerned about rodent control. There are already restrictions such as keeping it off the ground. My pile of leaves is on the ground and I have no fears.

Maybe it's just a university doing a limited study on something they are concerned about.

[bower]

Well.. I agree with zeuspaul that the talk of 'elites' is a bit much, and the sort of rhetoric normally assigned to Controversial here, because of its political connotations. I didn't want to move this thread because the study was so widely commented in the media, and left people with a lot of questions that might not be answered if we only discuss it in "private" due to the hyperbole associated with the second link in the OP.
Paranoia - this is when your fears have no basis in fact. When there's no evidence to support it.
So we really should stick to the facts or the thread will disappear into the darkest corner of Area 51, where most of us gardeners don't go.

No study is perfect. This one has serious limitations. And the take home we should remember is that your footprint is NOT 6X conventional agriculture for having a home garden or community garden, as was widely publicized with this poorly supported study.

[bower]

Speaking of evidence, WRT concerns about policy @karstopography I went to the trouble to spend some time looking for evidence, and I found a few things that relate to household waste diversion and large scale composting. They happen to be from the USA but similar initiatives are happening elsewhere. However the key point is that there is ZERO interest in stopping urban agriculture or community or home gardening and composting that I could find.
The powers that be are interested in large scale waste and large scale composting, both for energy and for carbon sequestration in conventional farm soils or other, to reduce the footprint on the scale that's relevant.
For example, Massachusetts brought in a law requiring businesses that produce more than one TON of organic waste per WEEK, to divert it from landfills. As it turns out, there's money to be made in composting these rich sources of waste (NO they're not coming for our kitchen scraps! They don't need em.). Interesting story:
https://www.epa.gov/snep/composting-foo ... hing-going
How policy led to a law, promoted commercial composting, created jobs, but then polluted the water. 2020 story.

I also found this review of some current policy initiatives by Biden's government to add compost to conventional farm soils, probably part of the international '4 per mille' initiative to sequester as much carbon in the dirt as we can in the next couple of decades.
https://www.csis.org/analysis/soil-carb ... -proposals
Whatever we may think about it, they're not coming for your BBQ pit or your garden, not at all. The evidence says they are looking to do stuff on a larger scale, which has multiple benefits (potentially) by improving the soil on the big farms while tucking away some carbon.

[Shule]

Good thing our garden is rural.

I think the benefits of a garden for the planet far outweigh any carbon footprint involved. Plus, I don't suppose they measured how much carbon the plants eliminated. I imagine most plants in home gardens have more leaves than many of the space-saving commercial plants (nothing against those plants, but I imagine they rarely if ever have an indeterminate tomato plant that takes up 25 square feet). Factor in how much went into each plant by comparison, and yeah.

[Moth1992]

The problem is a lot of reporters have not read the article and have concluded "study say gardens bad". Like the title if this post. When the conclusion of the report is not that at all.

Its really sad how reporters cannot understand scientific reports or analysis.

[Frosti]

Im surprised extensive use of peat isn't mentioned in this discussion. Just by the title of this thread, that's what I thought this is about.