Increasingly, we’re being made aware of how the fuels we use affect the environment, particularly with regard to causing global warming by the increase of carbon dioxide (CO2) and other ‘greenhouse’ gases in the atmosphere.

Most greenhouse gases are created by the use of fossil fuels like oil, coal, natural gas and propane. Burning such fuels produces CO2 from the ancient carbon they contain that was, until their extraction, locked up within the earth. The CO2 released into the atmosphere, where its concentration – and the resulting problem of global warming – is increasing. However, burning wood does not contribute to global warming because the process is part of the carbon / CO2 cycle in the same way that naturally decaying trees are. Carbon dioxide is taken in from the atmosphere by trees as they grow and becomes locked up in their wood (approximately half the weight of dry wood is carbon, derived from the air). It is later released when the tree dies and decays – or when it is burnt. Of course, sustainable use of wood requires that trees are replanted – and, in the current circumstances, we should be planting many more trees than we are cutting.

Image courtesy of NZ Wood
For more information check out the NZ Wood Website

Globally, we will worsen the present ecological imbalance if the world’s total forest area continues to be reduced. Disastrously, in many regions clear-felling without replanting remains the common practice. Whilst we must campaign to conserve the remaining forests of the world, and for the introduction of sustainable forestry and the efficient use of fuel wood, what we do in our own locality – and our own homes – is also of prime importance.

Wood from properly managed forests is a sustainable, renewable and environmentally acceptable fuel. It can be locally produced (and even home-grown), reducing the need for extensive transportation. It can replace fossil fuels for heating, thereby reducing their consumption and having an immediate environmental benefit. Efficiently burnt in appropriate appliances, it is generally non-polluting – once lit and warmed up, a good wood burner at optimum performance should not produce smoke (which comprises harmful particulates).

Solar power from the sun, wind power, and wood energy are renewable resources, meaning they can be used forever without depleting the earth. “Using renewable energy is like living off the interest earned by the earth’s assets, and never touching its savings.” (www.woodheat.org)

Aside from the issues of ecology and sustainability, wood as fuel can be extremely economical. Every year in the UK alone there are millions of tonnes of wood literally thrown away. Forestry thinning and timber wastes from industry and construction are usually discarded as ‘rubbish’. All this can be salvaged for fuel wood, and when burnt will add no more CO2 to the atmosphere than it would have done anyway by decaying.

If fuel wood does need to be purchased, its price compares favourably with other less-desirable fuels, particularly if bulk supplies can be obtained. The main problem with using wood for fuel is that it needs a suitable storage space and some hard work put in as preparation. However, all that cutting and chopping will help to keep you fit and healthy. It is wise to use the spring and summer months to build up an adequate stock of cut wood to get you through the following winter – ideally, freshly cut wood should be split and stacked to dry for 6 to 12 months before use.

For fuel wood to be used at maximum efficiency for heating requires a properly-designed, installed and maintained wood-burning stove set within an insulated building. It should be of the correct size for the location and its needs. Firewood should be dry, seasoned and cut to an appropriate size. For efficient heating and to protect the environment, it is recommended that wood that is wet, ‘green’, treated, painted or re-manufactured (e.g. hardboard, plywood, MDF, etc) is not burnt. Driftwood taken from seashores will contain salt: burning it will release harmful toxins and may also cause corrosion of the stove. Coal, plastics and household waste should not be burnt in a wood-stove.

Most hardwoods are excellent fuels, with Black Wattle, Ti-tree and Eucalypts being especially recommended. Willow and Poplar are also very good. Dense hardwoods are great for sustaining an established fire, while fast-burning softwoods (such as Totara, Pine and Macrocarpa) are used when building a fire to quickly establish efficient combustion temperatures. If planting new trees specifically for fuel production, a mixture of species is best. Fast growers will give the quickest return, whilst slower growing species tend to give the better quality fuel woods.

Existing unmanaged woodland can be brought into sustainable production with thinning and improvement, but this must be sympathetic to existing and potential wildlife. The general plan would be to first extract dead, dying and dangerous trees (whilst remembering that some dead and dying wood is essential in a balanced and varied wildlife habitat). Damaged and diseased trees should then be taken, followed by those that are weak, misshapen or crowded. Unsuitable or undesirable species and badly positioned trees should then be removed.

Once the woodland has been thinned, it should improve with better light penetration and less competition for the remaining trees. New plantings can be made using selected species and by encouraging naturally sown seedlings. A well managed, coppiced woodland will act as a carbon sink’ (taking CO, from the atmosphere), provide a habitat for wildlife and provide fuel for many centuries. It will also be a beautiful enhancement to the local environment.

On an industrial scale, wood can be used to produce bio-fuels suitable as alternatives to oil and petrol. Wood waste can also be processed into a pelletized solid fuel.

Fossil fuels are finite and their use jeopardises the ability of our planet to continue to maintain life. Wood is a natural, renewable resource and is the fuel for a future – invest in it by planting trees today.