There is An Earthly Chance that the world will come to realize that permanent sequestration of atmospheric carbon rests on the utilization of a plentiful natural resource – trees. Some fundamental facts about the importance of lumber as a construction material must first be understood before that realization can take place. First of all, we must understand that construction with concrete, steel and aluminum – unlike lumber – has a devastating impact on our carbon footprint. Roughly 40% of the burning of fossil fuels in the US and probably the rest of the world is due to construction with concrete, steel and aluminum. Secondly, we must get past the notion that skyscrapers and large buildings must be built with steel, concrete and aluminum. Large buildings can be constructed mostly with wood, such as the 70-story skyscraper to be built in Japan.[1] Wood has many advantages over concrete, aluminum and steel.
- Believe it or not, wood possesses greater tensile strength[2] than even steel.
- Being a relatively lightweight building material, wood outperforms even steel when it comes to breaking length (or self-support length)[3]. Simply put, it can support its own weight better, which allows for larger spaces and fewer necessary supports in some building designs.
- Electrical and heat resistance – Wood has a natural resistance to electrical conduction when dried to optimal moisture content levels (usually between 7%-12% for most wood species). Its strength and dimensions are also not significantly affected by heat, providing stability to the finished building and even safety implications for certain fire situations.
- Sound absorption – Wood’s acoustic properties make it ideal for minimizing echo in living or office spaces. Wood absorbs sound, rather than reflecting or amplifying it, and can help significantly reduce noise levels for additional comfort. Noise pollution is minimized.
- Beauty. With the wide variety of species available, wood presents an incredible range of aesthetic options, as well as providing varied mechanical, acoustic, thermal properties along with others that can be selected based on the need of the building project.
- Unlike concrete or metals, wood is a building material that can be grown and regrown through natural processes and through replanting and forestry management programs. Select harvesting and other practices allow growth to continue while larger trees are harvested. This is the basis of essentially permanent sequestration.
- When compared to building materials like steel or concrete, the life cycle of wood has a far lower overall impact on the environment than its counterparts and as a result, also costs significantly less to produce. Wastewater production and environmental impact are also significantly lower in wood manufacturing processes, particularly when compared to steel.
- Wood Emits Lower Volatile Organic Compounds. As a natural building material, wood emits significantly lower volatile organic compounds (VOCs) and carbon dioxide off-gasses than aluminum, steel, concrete and plastics (Figure 20). This is not, however, necessarily true of engineered wood products or composite wood products. Wood’s lower VOC impact is of particular benefit to homes and offices that are occupied on a daily basis. In fact, wood out-gasses natural organic compounds that relax people–it’s not just the warmth of wood’s color that creates such an inviting effect.
- Wood Enhances Energy Efficiency. Wood has a higher insulation rating than either steel or plastic because of its natural cellular structure. This means that homes and buildings require less energy to maintain heating and cooling, plus wood can help regulate humidity levels to a small degree. Hardwood floor installed over a wood subfloor may provide the same insulation value as a 22-inch concrete floor.[4] This insulating effect translates into lower energy costs, which is likely to translate to less burning of fossil fuels.
- Wood Is Biodegradable. One of the biggest challenges of many building materials, including concrete, metal, and plastics, is that when they are discarded, they take an impossibly long time to decompose. When exposed to natural climate conditions, wood will break down much more quickly and actually replenish the soil in the process. Wood can be recycled to extend its lifetime considerably before it decomposes and its carbon returns to the air.
The most difficult realization for many people, from the standpoint of Climate Change, is that only younger trees sequester carbon efficiently because of their rapid growth rate. Older trees do not sequester carbon efficiently due to their slow growth rate and in fact for many species, older trees release more carbon into the atmosphere than they sequester. Of course, some old growth forests are beautiful and may house vital ecosystems, and thus they must be preserved. However, if we are interested in effective and essentially permanent sequestration of atmospheric carbon, we must come to realize that the harvesting of older trees, accompanied of course by immediate planting of young and rapidly-growing younger trees, must be the objective. Deforestation also allows for intelligent forestry and the clearing of old dead wood and prevention of massive forest fires, which of course is in no one’s interests, especially that of climatologists.
One cubic yard of lumber is approximately equal to one ton of atmospheric carbon. The average home that is built with lumber requires about 17 cubic yards of wood, and thus it sequesters about 17 tons of carbon from the atmosphere, essentially permanently, because in 100-200 years if the house is torn down, the wood can be recycled into other products. The one thousand gigatons[5] of excess atmospheric CO2 that has been calculated to be the amount that would need to be sequestered to get us back to preindustrial levels,[6] calculates to about 60 billion homes that must be built to sequester it all. To offset those mind-boggling statistics, remember that huge buildings like skyscrapers and office buildings will be constructed as well.
There is An Earthly Chance that people will come to realize that sequestration into wood is relatively permanent, whereas sequestration into regenerative agriculture is limited at some point since the rate of carbon emitted into the atmosphere will eventually equal the rate of sequestration (see Figure below). Sequestration through wood-based construction suffers from no such limitation and is essentially infinite. There is An Earthly Chance that a thousand billion tons of carbon sequestration, that would likely eliminate all excess carbon in the atmosphere, will happen with regenerative agriculture within decades, and that’s then end of the story. However, there is An Earthly Chance that a thousand billion tons of carbon sequestration that would likely eliminate all excess carbon in the atmosphere will also happen when the world shifts away from polluting steel, aluminum and concrete to wood-based construction. The only downside to the lumber solution is that would take much longer, perhaps doable within this century. The upside to the lumber solution is that it is an essentially permanent (see diagram above) and it is unlimited.
All four technologies presented here that present the only possible solution to climate change, all provide marvelous health promoting outcomes for human beings and all earthly life. In an article published in the Journal of Environmental Quality[1], “biosolids”[2] were found to be superior to wood chips (WC), compost (COM), aerated compost tea (ACT) or a nitrogen plus potassium fertilizer (NK), for improving three typical urban soils and tree sapling growth. Thus, the nutrient-rich organic materials derived from our treated sewage sludge is a soil-enhancing nutrient for trees. The use of “biosolids” to enhance the rate of tree growth, not only helps to rapidly lock away carbon for centuries as trees are converted into lumber, but it also sequesters waste molecules which are harmful to humans, including heavy metals (arsenic, lead, mercury, cadmium and aluminum), pharmaceutical toxins (e.g., Prozac™ and other pharmaceutical metabolites), and other toxins (including radioactive toxins)[3] which are excreted by humans and turned into “biosolids.” These toxins could make their way back into drinking water and food, but there is An Earthly Chance that our waste toxins will safely be sequestered somewhere else, as they would be for centuries into lumber construction materials.
[1] Scharenbroch BC et. al. (2013) Biochar and Biosolids Increase Tree Growth and Improve Soil Quality for Urban Landscapes, J. Environ. Qual.
[2] Biosolids are the nutrient-rich organic materials from the treatment of sewage sludge.
[3] https://en.wikipedia.org/wiki/Radioactive_waste
[1] https://www.youtube.com/watch?v=B9EVnY6LqQ8
[2] the resistance of a material to breaking under tension
[3] that length of material hung vertically at which it will break through its own weight.
[4]http://www.bugwood.org/intensive/wood_s_advantage.html
[5] A gigaton is one billion tons
[6] Estimates vary of course, as no one can calculate this with any degree of accuracy.