The Green Tau: issue 43 

“MAKING SUSTAINABLE LIVING THE DEFAULT OPTION”

– strap line for the UN’s Earth Day. 


What is sustainable living? And how do we go about it? Something that is sustainable is something that can keep on going for a lengthy period of time without diminishment. We might look at household budget and apply the Micawber principle: 

“Annual income twenty pounds, annual expenditure nineteen, nineteen and six, result happiness.  Annual income twenty pounds, annual expenditure twenty pounds ought and six, result misery.”

As long as the required input is equal or less than output, the budget is sustainable. When what is consumed exceeds what is coming in, the budget is no longer sustainable. Sustainable living is the same: our lifestyle is sustainable if what we consume is equal to or less than resources we use. 

Let’s us taking heating for our homes as an example. 

If say we were to heat our homes with a wood burning stove, for that to be sustainable, we would need sufficient mature woodland to produce each year the wood we would burn. (This is not taking into account the cost to society of the pollution to the air). 

What if we hear our homes with oil and gas? That is ‘sustainable’ only in the short term as both these fossil fuels are non renewable. Once they are gone, they are gone. They cannot be replaced. Aside from air pollution, the major problem with soil fuels is the amount of carbon dioxide that they release into the atmosphere. It is a rate that far exceeds the rate at which it can be absorbed by the planet. This is why heating our homes with fossil fuels is not sustainable in either the short or long term. 

The most sustainable way of heating our homes is not to use any fuel but rather to build/ refurbish them with insulation levels that make extra heat (over and above our own body heat) unnecessary. Houses equipped to this standard are known as a “passivhaus” – https://www.passivhaustrust.org.uk/

Retrofitting is not without its financial cost which puts it out of reach for many people. (Sadly our government doesn’t understand that the whole nation would all benefit if insulating homes was state funded). Nevertheless any improvement we can make to the insulation of our homes will reduce our carbon footprint and energy bills and therefore makes heating our homes more sustainable: https://energysavingtrust.org.uk/insulating-your-home-back-to-the-basics/

A related area to that of heating, is electricity. What determines the sustainability of electricity?

Electrical production can be divided into two categories, renewable and non-renewable. Non-renewable electricity comes from power stations powered by coal/ gas/ oil. These fossil fuels are finite and cannot be replaced. Because of the scale of their carbon emissions, using them is highly destructive due to the adverse effects they cause of climate change and air pollution. Electricity produced by a fossil fuel driven generator is similarly non-renewable. 

Renewable electricity is produced using wind, solar, tidal or geothermal energy. These sources of energy are not diminished through use; they are available on an ongoing basis. In other words, they are sustainable.

Less easy to define is electricity produced using nuclear energy and that produced using biofuels such as wood chips, sugar cane etc. The amount of nuclear fuel needed in proportion to the energy generated is minuscule which is why nuclear power is often included along side renewables, but there are huge problem surrounding the safety of nuclear power stations and the disposal of nuclear waste that raises questions about its sustainability. 

Wood chips and sugar cane are both renewable resources but using them as an energy source is questionable. In a world where many go hungry and where more and more of the world’s natural or wild landscape is being lost, is it sustainable to use scarce land resources to grow crops for fuel rather than food?  

Questions around the sustainability of energy sources also apply to the sustainability of different forms of transport. The most sustainable means of transport is walking. It’s what we are designed for and uses no more energy than that required to feed us. The same is true of cycling, although according to Mike Berners Lee in his book, How Bad are Bananas, suggests that, depending on whether our diet is made up of beef burgers or bananas, a battery powered bicycle may have a lower carbon footprint! As above any transport reliant on fossil fuels – whether that is a petrol car, a diesel train or a plane – is not sustainable. Electric powered transport where the source of electricity is renewable is more sustainable but there are downsides to consider. Electric vehicles rely on batteries which are made from non renewable minerals such as lithium and cobalt – and cobalt in particularly comes predominantly from mines where employee welfare is minimal.

In sparsely populated areas, transport systems that rely on buses or trains may need to develop on-demand rather than time-tabled services, in order to make their use of limited resources sustainable. 

Plants are a naturally renewable resource but that doesn’t make all food equally sustainable. Factors to take into account include water, fertilisers, transport to markets, food waste, and whether the plants are feeding us directly or indirectly. Some crops such as rice, strawberries, blue berries and almonds,  require large amounts of water. In water sensitive regions irrigating such crops may divert water away from supplies used by local people for growing staple foods, as well as for drinking. It may also divert water away from aquifers and wetlands regions thus damaging local flora and fauna. In such circumstances, these crops cannot be classified as sustainable.

Fertilisers, especially artificial ones, use up limited non-renewable mineral resources, as well as contributing large amounts of carbon dioxide to the atmosphere. In addition the run off from fertilisers damages water courses and kills plants and creatures, compounding existing biodiversity losses. 

Where foods are imported over longer distances – and especially so when the mode of transport includes airfreight -will consume more resources and in particular will increase the food’s carbon footprint. Imported Spanish  strawberries, out of season avocados and air freighted asparagus are a few examples of unsustainable foods. In some instances the sustainability of a product becomes questionable when it takes over land used to grow staple foods for the local population or where it involves the clearance of indigenous wild vegetation such as the clearance of tropical rainforest to grow sugar cane. 

The majority of farm land globally is used not to feed people directly but to grow food for animals intended for human consumption.  It takes 100 x more land to produce 1kg of beef than to produce the equivalent in plant based food. In terms of feeding the global population a diet with high levels of meat consumption is not sustainable.

Plants as a renewable resource are also used for making things – clothes and fabrics, paper and furniture, rubber, paints etc. As with plants brown for food, similar questions about sustainability arise. Cotton for example is a heavy user of water – water abstracted for cotton growing was the major factor causing the disappearance of the Aral Sea. The growth in demand for palm oil used in products as diverse as lipstick and margerine, has led to the clearance of vast areas of natural habitat including mangroves. Demand for paper has seen naturally biodiverse forests replaced with monoculture pine plantations. 

The sustainability of every product we use needs to be measured in terms of renewability, carbon footprint, water footprint, impact on biodiversity, impact on local populations, the working conditions for those who grow, produce or sell, transport footprint, and the ease with which at the end of its life it can be recycled or disposed. Sustainability may begin as a question about individual lifestyle but quickly becomes a question about global sustainability. 

Author: Judith Russenberger

Environmentalist and theologian, with husband and three grown up children plus one cat, living in London SW14. I enjoy running and drinking coffee - ideally with a friend or a book.

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