What is the relationship between permaculture and sustainability?

Question

What is the relationship between permaculture and sustainability? What are sound reasons why both urban and rural permaculture takes us further down the road to sustainability?

Are there real-world cases where permaculture makes sustainability harder?

UPDATE as per request, here is a description of permaculture.

Permaculture is an approach to small to moderate scale agricultural production which involves trying to engineer mini-ecosystems which produce the foods and goods that we want to use. The ideal permaculture would have no external inputs once designed and implemented although like the ideal gas law, this is only an approximation and such do require human input and cultivation after design. Principles of permaculture design include:

1. Layering plants in space and time for mutual support and reduction in water loss.

2. Interplanting multiple species so as to ensure mutual nutritional support

3. Incorporating wildlife and wild plants into design of productive environments.

4. Biodiversity as the primary method of pest control

These tend to prevent mechanized approaches to farming, requiring human input for harvesting and low-grade influence to keep productive.

Answer 1

Since this is a part of the defining sustainability series, I am adding my own perspective here. Other perspectives of course are welcome and the whole purpose is to provide public insight into what's on and off topic here so please vote on these.

The problems @Pitt noted above are design issues with well understood solutions, which include biodiversity for starters (so that removing part of one species enables fallback on others). The larger barrier of course is knowledge. Permaculture involves working smarter rather than harder, and so reducing the overall energy inputs. This means humans have to do most stuff, you can't leave it to machines.

I think that permaculture is an important aspect of any attempt to become sustainable because it is sustainable itself, because we must mimic natural ecosystems in our own approaches to material and waste management, and because it cultivates interconnected and sustainable communities on all levels. This is not to say that there aren't challenges regarding human inputs and knowledge levels, and that these may have impacts elsewhere. On the whole, I think that widespread permaculture is a good thing however.

Permaculture is Sustainable Itself

Permaculture is sustainable with few external inputs. Permaculture utilizes processes of evolutionary ecology to replace most of the external direct energy inputs aside from the sun, as well as all indirect inputs beyond the initial design and implementation phase. This largely cuts fossil fuels out of the system of food production.

Permaculture utilizes carefully chosen plants and domestic animals, as well as sometimes wildlife, for pest control. For example one might plant thorny hedges to keep deer out of the food production area, while providing habitat for birds of prey so that that they can prevent rodents from becoming a problem. Pests an never be entirely eliminated because predators always lag behind pests, but in this way they can be controlled so that they do not cause substantial damage in established permacultures. A good beginner's book on this subject is Gaia's Garden.

A second point is that species are arranged in ways which mutually support eachother. I haven't been able to experiment with this but a example of an area where this might be helpful might be co-raising cattle and horses, together in an area that has snow so as to minimize the need for hay. Cattle won't eat what they can't see so they tend to starve quickly when it snows, but horses will kick the snow away to eat. Thus the horses can be used to help the cattle forage in winter. If areas are maintained with sufficient forage, hay may not even be necessary (there are recorded cases of cowboys with herds stuck in winter storms following mustang herds in order to ensure the cattle could eat, and thus saving their herds).

The Necessity for Material Lifecycles to Mimic Ecosystems

In an ecosystem, the waste product of one species or element becomes the input of another. Bears poop in the woods. Micro-organisms break down the poop and they release waste products which plants take in. Those plants may produce fruit and the bears eat the fruit. The bears then poop and the cycle repeats. This example shows the way in which nutrient cycles work in ecosystems, re-using and re-cycling all components and over time building quality soils and very efficient ways of transforming current solar energy into biological energy.

Sustainability requires, among other things, that we stop polluting our environment with things which cannot readily be re-used in the biological context. For this reason it is very important to develop closed material lifecycles. Our current factory-to-landfill must eventually be replaced with a closed cycle where very little if anything ends up in land fills because everything is re-used in some context or another. Doing this requires in essence having the output or waste of one system becoming the input of another. Recycling is one way this can happen (re-use is another), but either way waste must be re-purposed as an asset. An example might be privatizing sewage treatment, not as a waste disposal service, but as a series of cooking gas and fertilizer factories. Waste products which cannot be recycled can be re-used in unexpected ways, such as building things out of "urbanite."

The shift in thinking from a factory to landfill pipeline to a series of interconnected and infinitely continuous series of material lifecycles (akin to the water cycle, or to nutrient cycles in ecosystems), is absolutely necessary to achieving sustainability, and permaculture teaches this quite a bit. This is a reason why I am such of a fan of urban permaculture. While the idea of feeding a family of 4 on a city lot is probably unrealistic, the lessons learned about sustainability and the increase in free time from doing so (instead of high maintenance flower gardens!) is well worth it. Most of my "flower gardens" also produce fruits and veggies, they look nice, and they require very, very little maintenance.

Sustainable Communities

The emphasis on the output of one component being the input of another has the potential at least to build close-knit, sustainable communities through garden exchanges, and also things like thinking about what one can re-use things that would otherwise be discarded. Urbanite as a building material for small projects (say outdoor pizza ovens) comes to mind but the possibilities here are really endless. The more we think about what we can do with waste, the less of it ends up being discarded in unsustainable ways and the closer we become as communities as we utilize the waste products of neighbors and vice versa,

Sustainability Challenges

The big one actually is manpower (and this is an issue for most green energy too btw but for very different reasons), and the second is education. Building permacultures requires years of practice and/or significant training. It also turns food production into an intellectually challenging activity. However it is also less physically challenging than conventional agriculture in many cases, and so there are possibilities of closing loops here. The problem with manpower though is not so easily overlooked. With modern fossil-fuel-based agriculture it is not hard for an individual to successfully farm vast tracts of land, possibly in the hundreds of acres, with only seasonal help. Permaculture requires more people to be working in food production. It also requires that people make more careful choices regarding foods to consume (grains are less sustainable than chestnuts for example, and wheat is less sustainable than rice). More people in "farming" full-time means fewer people engineering green energy solutions and the like. Competition for manpower is thus a significant concern as I see it.

TL;DR - Short version

I see permaculture as pretty close to a necessity for achieving sustainability both due to its direct effects and also its indirect effects. I also see permaculture ultimately as the best current training ground for the sorts of patterns we must develop in order to achieve sustainability generally.

Answer 2

I think this is a very good question which is quite a challenge to permaculture. The answer depends on what it is you are trying to sustain.

My understanding of the aims of permaculture is that it attempts to sustain the people dependant on the system while minimising other impacts. So it aims at sustainability at the household scale. What this doesn't address is how these solutions scale in practice where the biggest problem is land use. The land used depends on the property size. A typical minimum rural property size in many parts of Australia where it originated is 40ha. This is not scalable to support 7 billion people as there is less than 1ha per person of habitable land.

Permaculture properties are usually very unproductive per unit area, maybe because there's little point in producing more than you can use. I've also seen PC production where much of the produce isn't harvested - maybe it's too much work or you can buy nicer food. I have heard claims that high production is possible but have been unable to substantiate these.

Some view the sustainability as a trade off between sustaining production long term and short term production intensity. When I have discussed global land constraints with permaculturalists I have had the response that there are too many people. If this is the case then under permaculture the human population would not be sustained.

The problem with less intensive agricultural production is that more land is required and this impacts biodiversity, which is not sustained. To sustain the maximum amount of biodiversity it is preferable to use as little land as possible to produce our food.

Sources:PDC course 1990, permaculture farm tour, France, 2015, government scientist in NRM, PhD on impact of agriculture without petrochemicals on biodiversity, published papers on this and visited many PC properties.

Answer 3

Although I am far from an expert on permaculture and sustainability, I would think by your definition of permaculture one obstacle would be to source the materials and resources needed to establish a permaculture.

Surely as soon as you can harvest your permaculture, and you do so in a way that enough resources prevail to enable to grow more of the harvested product, than by definition it should be sustainable. But the same problems arise from harvesting a permaculture than from traditional farming.
I suppose you'd have to design the permaculture in a way that it produces your product in excess and no organism within can really use it or is dependent on it, such that taking this product out of the permaculture would not impact any organism within. Otherwise you would always have to put something back into the system after harvesting so that it can grow again and the balance is maintained, so it risks being unsustainable.

Unfortunately I can't provide you with any real world examples. I just thought it would be a good discussion ;) and it's definitely an interesting question.