So... is the use of wood sustainable?

In recent years we have published numerous articles related to wood . From addressing the trends of its use , the possibilities of raw wood , the different types of boards , curved wood , its finishes , to its innovations in tall building structures or its behavior in the face of fire , the topic always generates a lot of repercussion . Specifically, the structures of Cross Laminated Wood (CLT)They have emerged as a highly efficient solution, in addition to presenting other thermal, seismic and even sensory benefits to the occupants, being pointed out by specialists as the concrete of the future . But when we post articles on social media, we always come across comments from our readers concerned about the impact of cutting down trees for all these uses. At the same time that we are betting on wood as the great building material of the future, we ask ourselves: is it possible to continue using wood? To what extent is it really sustainable?

Such concerns are not far-fetched. The wood comes from trees that grow in forests. Therefore, the use of wood is associated with deforestation, which not only destroys ecosystems and habitats, but also triggers the dreaded climate changes. According to a report by the WWF ( World Wide Fund for Nature ) [1], it is estimated that the amount of wood extracted in the world will triple by the year 2050. The demand for wood and paper tends to grow with the increase in population and income in developing countries, as well as increasing the use of wood to make biofuels, pharmaceuticals, plastics, cosmetics, consumer electronics and textiles.

The State of the World's Forests 2020 Report [2] states that since 1990, approximately 420 million hectares of forests have been lost due to conversion to other land uses, although the rate of deforestation has decreased in recent years. three decades. Between 2015 and 2020, the rate of deforestation was estimated at 10 million hectares per year, up from 16 million hectares per year in the 1990s. The area of ​​primary forest worldwide has decreased by more than 80 million hectares since 1990. More than 100 million hectares of forests are negatively affected by forest fires, pests, diseases, droughts due to invasive species and adverse climatic events. According to WWFIn 2019, the tropics lost about 30 tree soccer fields per minute.

The main cause of deforestation is the expansion of agriculture and livestock. Forest fires have been increasing in frequency and intensity in recent years. Unsustainable logging also causes degradation. Yes, it seems like an extremely bleak and disturbing scenario. In the case of civil construction, it is always important to keep in mind that to build, we almost always need to destroy. Every feature and decision in the project represents some kind of impact on the environmentAnd understanding where we can make the least impact is vital to real long-term sustainability. In this sense, wood is definitely a suitable material. Although it seems almost contradictory, the best scenario would be if we built more buildings of wood than of concrete, brick, aluminum and steel.

First, wood is a renewable material, if certain care was taken during its extraction. This means that, unlike non-renewable resources such as oil, coal, stones or other natural resources, the forest can continue to grow normally even if some trees are cut down. If sustainable forest management is carried out and trees are planted frequently, we may have wood available forever.

When plants photosynthesize, they remove CO2 from the atmosphere and store it in wood. This is what we call "carbon sequestration". The sequestration rate is highest during the young and vigorous growth of the plant. Therefore, growing forests are a sustainable way to reduce the greenhouse effect, even more than old forests (obviously, keeping old forests intact whenever possible is interesting to maintain ecological balance). As Think Wood noted , active forest management or forest thinning mitigates wildfires, reduces carbon emissions, replenishes waterways in the area, expands wildlife habitat, and creates jobs in rural areas.

Another positive characteristic of wood is its low embodied energy , which refers to the sum of the impact of all greenhouse gas emissions attributed to a material throughout its life cycle. Unlike steel or concrete, for example, wood requires a minimal amount of energy-based processing.

A comprehensive academic study , summarized in this text , indicates that replacing other building materials with wood could save 14% to 31% of global carbon dioxide emissions and 12% to 19% of global fuel consumption fossils.

But you have to be careful. If forests start to harvest faster than they are replenished with new trees, there is a real possibility that we will have a serious wood shortage. As architects, it is essential that we seek the origin of all the materials with which we work. The designer must be the first to realize that not only the quality and costs of the materials are important, but also where they come from and how they are exploited. Another advantage of wood is that many species can be reused if they are recovered and separated from other wastes. Other waste can also be collected and used to make particle board and other modern composite products.

When the demand for new wood is higher, one way to ensure that the source is safe is through certification stamps. The most traditional is the Forest Stewardship Council (FSC), an independent non-profit organization that promotes responsible forest management around the world. Certified wood comes from sustainably managed forests, preventing damage to ecosystems, watersheds, wildlife, and the trees themselves. The certified wood has the FSC seal to facilitate its location. More than 380 million acres of forest are FSC certified worldwide. According to WWF , around 30% of world forest production is certified, and around 13% percent by FSC.

The challenges of the contemporary world in relation to the exploitation and excessive consumption of resources have forced us to rethink many crystallized truths. And, answering the question in the title. Wood can be extremely sustainable and an incredible building material, provided it is explored and treated in a conscious and respectful way.

[1] Wood as a Sustainable Building Material. Journal Forest Products. September 2009, Vol. 59, No. 9.

[2] Food and Agriculture Organization of the United Nations. The State of the World's Forests 2020.