Sustainability

Clay is an abundant resource, although in practical terms not a renewable one, resulting - as it does - from the gradual weathering of igneous rocks. Its abundance means that depletion of the material itself is probably not the main issue for studio potters, certainly in comparison to industrial ceramics. Nonetheless, there are energy costs in digging, processing and transporting it to make the clay bodies most potters use. I do use commercially prepared clay (UK sourced - currently from Stoke-on-Trent). However, I am also, increasingly, working with locally sourced 'wild clay’.

One of the great advantages of clay is that until it is fired it is completely recyclable and all my waste clay is reclaimed and reused. Cleaning (hands, tools, surfaces) is done with a bucket system which allows the clay to settle out of the water and be reclaimed.

Other materials, particularly those used for glazes, present more of a challenge. For stoneware most of my glazes have wood ash as a main ingredient. The ash all comes from wood that was already being burned, largely donated by friends with wood-burning stoves. (Nothing is straightforward, however: we know wood burning stoves, particularly in urban areas, make a very significant contribution to fine particulate pollution.)

Other ingredients are minerals that are both abundant and produced in the UK (quartz, potash feldspar, whiting, ball clay). Where glazes get trickier is with oxides and other colourants. I just use iron oxides (red, yellow and black) and, occasionally, copper oxide. I don’t use colourants such as compounds of cobalt, chromium, nickel, barium and manganese, for reasons including rarity, toxicity, transport distance and worker exploitation.  

Although generally I avoid lead based compounds in glazes, the exception is in the Medieval pottery work, where a simple glaze using fritted lead (lead bisilicate) has been used. In other earthenware work I use borax frit as the glaze flux. However, the manufacture of frits involves incorporating the key ingredients with silica at high temperatures, then cooling to produce a glass and grinding it to a powder. This, of course, adds another energy overhead to the materials.

Making ceramics of any useful, functional, type requires firing clay to temperatures between about 800 °C and 1300 °C, depending on the type of clay. The energy required to do this is significant and is generally produced by direct combustion of wood, oil, or gas, or by electric heating elements.

All these result in release of carbon dioxide (plus other things) into the atmosphere. While modern electric kilns are very efficient and release no CO₂ at the point of use, the issue of course is how the electricity is generated. Whilst ‘green electricity’ from the UK grid is not actually zero carbon, it is the one energy supply that has the potential to be so,  and so must be the future mainstay for sustainable ceramics. We buy our electricity from a supplier which accountably puts into the grid equivalent renewably generated electricity and invests in renewable energy infrastructure. Short of generating our own clean power this is about the best we can do at the moment. To put it in perspective, firing my larger (7 kW) kiln takes about the same amount of power as charging our small electric van three times.

For reasons of energy use and work flow all my work is single-fired. Firing once rather than twice is discussed in more detail here and whilst it doesn’t halve the energy use it does reduce it, probably by at least a third.

So what about wood firing? In terms of CO₂ emissions the same arguments apply here as used for the sustainability of biofuels more generally - with the same caveats (time scales, energy used in preparation and transport, particulate emissions). The wood firing I do is as part of the medieval pottery work, firing the earth kiln. These firings are occasional and are done almost entirely with scrap wood sourced from the farm where the kiln is located. This is all waste wood due to be burned anyway, so we are not using wood which could have found more permanent use and we are putting the energy to good use. Not perfect, but about as good as we can make it.

Whilst materials and energy use are without doubt the biggest sustainability issues with making pottery, there are other things where we can make a difference.

Plastics are incredibly useful for potters - primarily for storing materials (bins, buckets and bags), for keeping clay and pots from drying out, or drying too quickly, and for packaging pottery to be sent by post. In the first two cases I do use plastic, but almost never buy it - re-using plastic containers and bags already in use provides pretty much all that I need, and keeping existing plastic in use as long as possible, rather than throwing it away is a small step to reducing both plastic pollution, and the use of oil to produce new plastics.

In terms of packing, this is one area where it is possible to be completely plastic-free - as many potters already do - by using paper (especially recycled/reused), cardboard, paper tape, and if necessary loose packing material made from cellulose, or starch, materials which are easily biodegradable.

A less frequently discussed aspect of the final stages of a pot's production is the delivery to the buyer. In Yuliya Makliuk's life cycle analysis the contribution of the firing to the carbon footprint of a ceramic mug is typically less than that of air freight delivery from Europe to the US. Sell (and buy) locally!

And finally, having a digital presence. This web site is hosted by a UK company - Kualo - chosen in part at least for their environmental sustainability principles, which can be found here. Short of not having a web site it is about as good as I can do at the moment.

There are many judgements and compromises involved in all these decisions, but I try to work to the principles of minimising transport distances; recycling materials; avoiding materials that are scarce, toxic, or sourced in unethical ways; and using renewable energy (as sparingly as possible).

These are the minimum principles I feel I need to try and work to and, of course, these need to be complemented by equivalent choices in other areas of life such as food, travel and housing. And we have to be wary of the assumed equivalence of activities: reusing plastic sacks and recycling clay does not offset the environmental costs of a trans-Atlantic flight - but at the same time it doesn’t mean the former is not important.

In discussing these issues it is hard to avoid the choices one makes oneself becoming implied criticisms of those who do something different. Sadly, this inhibits the frank conversations we need to have about responding to the environmental crises we face. Whilst one person making these choices will make no material difference to the future, it is also true that a sustainable future cannot happen unless most of us do.

• Bloomfield, Linda (2020) How to make your pottery practice greener. Crafts Council

• Craft in America (2021) Artist Studio EcoGuide

• Galloway, Julia (2021) Eco-responsible ceramic studios. Craft in America. [panel discussion]

• Galloway, Julia. Field guide for ceramic artisans. Chapter 10: Environmental Impacts.

• Gers, Wendy (2021) Green ceramics: exploring environmental practices.

• Joyal, Denise (2011) Aesthetics and environment: kilns and carbon. Ceramics Monthly (Feb)

• Old Forge Creations (2021) The CO₂ cost of pottery.

• Oxford Clay. Publications for eco-conscious potters

• Potclays Ltd - (2021) Sustainability. Technical Information Sheet

• Schimik, Kristin (2018) Let’s have a discussion: Sustainability in the ceramic studio. Ceramic Arts Network.

• Smith, Isabella (2021) 7 makers and studios turning ceramics green. Crafts Council