The carbon cycle of wood

Wood is a renewable and versatile raw material. At the end of their first life cycle, wood and wood products can be:

• Reused
• Recycled
• Used as a source of energy containing neutral carbon

The production of wood products and by-products generates very little waste, because almost all these products are used as a raw material or as a source of energy. Wood residues, splinters and sawdust are used at production sites to produce heat and energy and, outside them to produce panels and/or paper. Moreover, there is an increasing interest in this source of energy to feed power stations using biomasses.

The boost to recycling

It has been estimated that wood consumption in Europe amounts to 160 million tons. 15 million tons are recycled every year, a quantity that tends to increase over time, also thanks to the divestment of underground dumps for rejected wood. A further boost to recycling will be given by European regulations on package waste, which will require the presence of 15% of recycled product in all packages. The forest industry considers recycling as an integral part of the production process carried out according to sustainability principles. For example, the ratio of sawdust in the production of chipboard panels has changed from 1/3 (1970) to over 3/4 today.

Thermal efficiency

The use of wood to build highly thermally efficient buildings offers several advantages, also in terms of control of costs, compared to the use of bricks or alternative materials. Moreover, triple glazing windows can be produced more easily with wooden frames and wooden floors give better heat insulation compared to concrete ones. In 2002, the European Energy Performance of Buildings Directive (EPBD) introduced regulations on energy efficiency for residential and non-residential, new and already existing buildings. Wood will favour therefore the energy efficiency of the buildings of the future. It is really sustainable and inexpensive. Taking into account the increasing importance of building technologies with a high energetic efficiency, it is evident that wood will play an increasingly important role in the future.

Energetic factors

The energy used to extract or produce a material or a product is called “incorporated energy”. In general, the higher the incorporated energy, the higher the relevant CO2 emissions. Compared to the high emissions and incorporated energy of alternative materials such as steel, concrete, aluminium and plastic, wood is characterized by a low content of incorporated energy and CO2 negative emissions, thanks to the "carbon sink" effect. Even when materials such as steel or aluminium are recycled, the process requires a high consumption of energy.