It's already been asked to what degree could carbon farming is a “solution”. As I've observed elsewhere,
I don't think it's a solution, but a wedge. So, how big a wedge? This question is answered on page 37. Current CO2 concentrations in the atmosphere are around 407 parts per million (ppm), and rising worryingly fast:
https://www.co2.earth/ (it will drop back a few points over the summer, before peaking at an even higher level next winter). If the hypothetical maximum quantity of carbon we can sequester in soil is in the region of the equivalent of 50ppm of CO2 (the figure given by Toensmeier), we expect to peak at 450ppm (which I think is looking increasingly optimistic as a result of the ongoing lies peddled by climate change deniers), and we need to return to a maximum atmospheric concentration of 350ppm, then
the answer is “less than half”.
That's actually a big wedge, but there are some big caveats. The first is that 50ppm itself is pretty optimistic, and reflects a theoretical maximum. The second is that there is no guarantee that the carbon will stay where the plants put it (especially if we use livestock to convert some of it into methane, which is an even more powerful
greenhouse gas). The third is that the other means of sequestering carbon are currently science fiction.
http://www.theecologist.org/blogs_and_comments/commentators/2772427/survivable_ipcc_projections_are_based_on_science_fiction_the_reality_is_much_worse.html Lastly (of the big ones, or this will turn into a thesis not a forum post) is that we are on
course for much higher that 450ppm (the
Intended Nationally Determined Contributions, post the Paris
summit sick joke, put us on course for 670ppm and a cataclysmic 3.5C of warming.
It's not a solution: it might be a big part of a solution, but we are currently lacking other parts of that solution. We're not just talking about putting carbon back in the ground, but about keeping it in the ground:
http://www.theguardian.com/environment/series/keep-it-in-the-ground
So, with that out of the way, what ideas make most sense in terms of maximising the size of that wedge?
I particularly like the section on
homegardens and related matters (pp. 42-49). On the other hand, I think it's going to be difficult to extend the idea into industrialised societies, where people have left or been forced off the
land by the intensification of agriculture and by the demands of the 1% for factory labour. These are incredibly diverse habitats by almost any standards, and my own forest garden plans would be comparable to a temperate or subtropical homegarden. There is an urgent need for research into planting lists and schemes for temperate and subtropical zones, as well as thought on the subject of how climate change will drive successional processes (something inadequately discussed in Toensmeier's earlier work (see
https://permies.com/t/20162/books/Edible-Forest-Gardens-Volume-Dave and
https://permies.com/t/41448/books/Winter-Read-Edible-Forest-Gardens).
One problem, and I want to come back to this, is
weak research. There are good studies conducted on such systems in the tropics, but we know much less about how they might work in subtropical and temperate zones, especially in terms of carbon sequestration. I think it's a safe
enough bet that they will sequester carbon, and there is some research that points in that direction, but it's clear that studies are needed.
Another is that this weak research has
led us to a situation where we have some idea of the likely range of
net primary productivity, and thus carbon sequestration potential, even if we need to work out the details, but we know very little about
yields. Very few people in
permaculture and/or growing what might be termed temperate homegardens have measured their yields, although I've seen plenty of anecdotal complaint about low levels of protein. I have no idea whether this is a result of high expectations (most people in developed nations consume too much protein), poor design or a problem inherent to the concept.
I reviewed one of the documents cited here:
https://permies.com/t/56228/books/Permaculture-agroecology-design-movement-practice What is clear from this book and this reference is that
the failure of permaculture to actually address a range of valuable scientific questions in relation to a number of agricultural practices may have set the establishment of good practice back years if not decades. This is something I think we need to be addressing as a matter of extreme urgency, and not continue to make inflated claims on the basis of limited or non-existent evidence:
I think one of this book's great strengths is how it
informs the practice of agroecology as much as it informs the practice of permaculture, and may even lead to better sharing of information between the two. Given that my own thought is increasingly driven by the science and practice of agroecology, I'd be keen to see this happen. Agroecology began among poorer farmers, few of whom are Caucasian, and many of whom are women, while Permaculture has had a tendency to be driven by Caucasian males, often with a mentality informed by dominance over the rest of the planet. It's often asked where the women are in Permaculture, and I think this is a fair question. Toensmeier (p57-8) specifically talks about the
empowerment of female farmers. He recognises there is a clear gender gap, a consequence largely of structural socio-economic issues that need to be addressed, both in the overdeveloped world and elsewhere.
As one of my digressions, I'd observe that Permaculture could do with an analysis informed by intersectionality theory, but that's a long post on another
thread probably better written by someone who is not a white, cis, het male.
The main problem with extending this model further is the existence of the large farm, whether extensive or intensive. To me it underscores the
need to push a social transformation as well as an agricultural one. As far as I can see the only way to make an extensive homegarden work would be some sort of collective model, perhaps a co-op.
Otherwise you run the risk of having a big landowner with some variant of serfdom, either with lots of economically desperate “volunteers” (or, in the short term, WWOOFers) or a similar arrangement with cheap wage slavery. Needless to say, this does not appeal.
If anything what this book has helped bring into focus is how the threats imposed by climate disruption, coupled with the socio-economic structures that brought it about, necessitate a complete revision not just of agriculture, but of society. As Naomi Klein argues, this changes everything.
http://thischangeseverything.org/
I'd agree, and those changes are very radical.
As I've observed on another thread (
https://permies.com/t/55829//Read-Carbon-Farming-Solution-Eric) carbon sequestration payments on a broad scale at the social cost of having the stuff in the atmosphere would a) break the bank and b) involve shovelling massive payments in the direction of rich land speculators, as well as violating the basic principles of how a fee-and-dividend scheme might work. This could be used as redistributive justice for those farmers in the developing world most likely to suffer most from a problem they often did least to cause, but without a different model you can bet it won't happen. Vigilance is necessary, because those same vested interests who caused the problem will certainly try to both shirk responsibility and do their level best to
profit again from it.
The other problem with this model is that it would involve predicating paying to sequester carbon on pumping more of the stuff into the atmosphere. There is more on financing in part 5, so I think this is probably something to be returned to later.
A smaller-scale carbon-farming system would work where you can find a hectare or two for a family, although again a redefinition of the word family might be called for: this might not be two adults (whether heterosexual or otherwise) and 2.4 kids. Much may be learned here from cultures outside our own, and this may be one of those areas where we are limited by language and
experience.
On a directly related note, I came across a concept recently of the “marriage co-op”, centred round a farm. The details of how this would work were not clear (it was in a work of futuristic fiction), but the notion seemed to involve several adults in some sort of marriage contract, with legal title to the farm inherited collectively by the children.
Needless to say,
I can see why many conservatives are so freaked out over climate change: the realities mean not only dealing with the fact that their system has involved treating the atmosphere as a sewer (and soil as an endlessly renewable resource to mine the nutrients from and then dump the results into the sea, in complete contravention of even basic understandings of nutrient cycles) but that we also need radical social changes – because the main alternative to the above would involve state ownership of the means of agricultural (and by implication industrial) production: i.e. Communism. At the very least the broad-scale farms will need to be broken up or brought into collective production, whether owned by the community or by the state. Prior attempts at the latter have, of course, proved to be less than successful as an economic model.
As we continue to read and discuss this book, I'm liable to have little patience for those attempting to assert their entitlement either to the conventional ownership of broad swathes of land, the profiteering from the occupation of state-owned land or of the maintenance of the status quo more broadly. One of the places where
I fundamentally disagree with Toensmeier is that we are going to need to see major changes in human diets, whether he or many others like it or not. Personally, I think that's a good thing, especially if it comes with a resurgence of
local and regional culinary traditions, and more
sustainable ways of relating to other humans and the rest of the planet.
In fact, this is a point where I see a contradiction. He is keen for people in the Global South to change their diets, but seems keen to allow a lot of meat production, so that people in the Global North don't have to change theirs.
On page 27 he talks about
livestock, and I'll come back to this with some comments on Part 2 at a later date. It's no secret to those who have read my posts elsewhere that I think that the keeping of livestock is largely, if not completely, incompatible with permanent agriculture. I followed his main reference on page 27 back through the literature (his reference led to another), and found it here:
https://nicholasinstitute.duke.edu/sites/default/files/publications/ni_r_10-04_3rd_edition.pdf This is a non-peer-reviewed document which seems to support the hypothesis, but it involves the replacement of
native grasses with higher-yielding varieties (which completely contradicts claims by ranchers, even ones practicing mob stocking or what they misleading call holistic management, about restoring prairie). Intensification of pasture production through these processes may be negative. It may be, but the conditions under which it may be are complicated, and the research is often contradictory.
What is also clear is that many of the “success” claims about soil as a result of grazing may be the result of any of a combination of several other practices, such as cover cropping and no-till practices (for instance this study found “that the relatively low rate of grazing did not significantly affect the amount of organic matter in soil and did not cause soil compaction”
http://onpasture.com/2015/12/07/no-harm-to-soils-when-cattle-graze-cover-crops/ - obviously this is bad because we want systems that
increase the amount of organic matter), as well as supplementary feeding (eg Savory and Salatin) and the addition of
compost (eg the Marin
project:
http://www.marincarbonproject.org/home – which is also bad because here we have a system using scarce compost for minimal return on carbon sequestration).
Rates of sequestration are lowest where existing carbon levels are highest, which means that carbon sequestration is more likely to be offset by nitrate and methane emissions. Improving carbon sequestration rates on low-carbon grasslands depends on reducing the stocking rates and, because such grasslands tend to be less productive, using supplementary feeding. That said, the research in this regard is also ambiguous: several studies have found that this practice reduced soil carbon.
According to this document, “rangelands have low C sequestration rates on a per unit basis, but because of their vast area, they could capture 2%–4% of annual anthropogenic GHG emissions on a global basis” (Nicholas Inst. p.37) This estimate differs somewhat from Savory's but is consistent with the science:
http://www.realclimate.org/index.php/archives/2013/11/cows-carbon-and-the-anthropocene-commentary-on-savory-ted-video/.
In other words, grazing can, under certain circumstances, result in carbon sequestration (and what you end up with is not prairie), but it's tricky to generalise, and you are generally better off doing something else (usually involving planting
trees). Crucially, because of that vast area we would, in effect, be wasting vast areas of land (about 26% of the world's total land area, according to the FAO) on pasture sequestering dismally low quantities of carbon when we could be doing something more efficient with it – either turning it over to wildlife habitat or converting it to some form of agriculture that sequesters more carbon and produces more food because it's not passed through a herbivore first.
It is true that cows can convert more of the net primary productivity into food for them than we could trying to do it ourselves. The main reason for this is because pastures are deliberately sown with species with high net primary productivity, not high yield. Multistrata agroforests provide higher NPP (yields are, as I say, a more complicated problem, worsened by the refusal of many permaculturalists to investigate the question). Many annual crops provide higher yields, especially among the legumes.
In addition, the citation refers to practices in the US, on soil types found in the US, under their climate conditions. It seems to be difficult to generalise it further. Research elsewhere suggests very high net emissions for grazing on soils with a high carbon content. Sadly, Toensmeier doesn't mention this:
http://www.sciencedirect.com/science/article/pii/S0306919212000942
This is a subject that might (actually, probably will) bear revisiting later in the book, but it does emphasise the point that Toensmeier's literature survey may have been lacking. I'm not yet sure how widespread this problem is, or whether he's gone into more depth in terms of the research in chapter 7 (a quick read-through showed mixed results).
Another caveat relates to a comment on pages 15-16 on how
reductions in crop yields as a result of climate change may be offset by a couple of per cent as a result of increased atmospheric CO2. I think we need to be cautious of this figure and of other claims related to increased plant growth as a result of these increases (a myth peddled by the fossil fuel industry and repeated ad nauseam by deniers). It's true that we are seeing some small increases in the global rate of photosynthesis, but this is where CO2 is the main limiting factor. As soon as the local environment finds another limiting factor (
water and either macro- or micronutrients) this increase will slow or stop. He's not wrong, but the reality is more nuanced.
Another question about yields is raised on page 57. At a practical level I want to know whether those lower yields for perennial crops are offset by additional yields in the understorey: I may end up with fewer apples than I would in a monoculture orchard, but I also want to know the implications for harvests from the understorey. Chapter 6 in Part 2, which I'll come back to in a later thread, talks about annual cropping systems: these can be integrated with perennials, and this may be a design question.
So, second impressions are that this is a good but flawed (although some of those flaws could be mere illusion: more study is needed) book that could have been twice the length, much more controversial, but
should probably be on a supplementary but not necessarily core reading list for both students of permaculture and of agroecology.
I think there are
issues with his research base. Some of them are unavoidable: the research isn't there. Some of them have to do with outdated material. For example, he cites Mark Lynas's Six Degrees: Our Future on a Hotter Planet: Lynas's work on warming was comprehensive, much more so than the basis of some of his more recent pronouncements
http://www.theecologist.org/campaigning/2987655/gmo_lobbys_false_claims_to_defend_gm_oilseed_against_deformed_butterfly_findings.html, but the bottom line is that he's still a
hack journalist, and the work is out of date; it's not wrong, but some of the uncertainties have been resolved in the nine years since it was published, which implies he could have found a better source. Sometimes I think he overstates or understates research conclusions in order to support his own conclusions: this is rarer, but the fact the book is referenced does mean it's possible to check, and this is a great strength.
I'm continuing to check.
2
