Building houses out of wood would significantly impact carbon emissions in a relatively short time scale.
The idea of planting trees, is limited in it’s application for one simple fact: What happens to the carbon in those trees once they’ve grown? It’s not going back into the ground, much of it is released back into the atmosphere when a tree dies. Basically, forests are good, but not the whole solution.
Using wood as a building material answers many carbon problems: It reduces demand for cement. The cement industry itself accounts for 8% of global CO2 production. The wood itself, built into building, acts as a reservoir for CO2. Very crudely, ~40% of the weight of wood is carbon, given a dry content of ~50% and a moisture content of ~8–25%.
Typically a wooden 150 m2 structure with weight about 15 Mg (1000 kg), therefore sequestering in the order of 9 Mg of carbon. That carbon on the other hand equated to about 33 Mg of CO2: The molecular weight of CO2 is ~3.6x higher than just carbon due to containing to oxygen atoms for each carbon atom.
Each ton of concrete, for which a 150 m2 build would typically require 80 Mg, produces ~1 Mg of CO2. Therefore, a back of the envelope calculation for CO2 saved is 80 Mg.
This equates to a net reduction 113 Mg of CO2 just building a single house out of wood.
For perspective, the per capita CO2 emissions in Portugal equate to about 5.1 Mg (amount of CO2 per person), therefore, assuming a life expectancy of 81 years, and an average occupancy of 2 building just the house you live in out of wood would reduce your lifetime CO2 footprint by about 13.5%.
Of course reducing the ecological marginal cost of house, isn’t the only upside of this equation. Other things to bear in mind with wood construction:
- The structures can last for many centuries, as proven by the many timber framed buildings in northern Europe.
House of Bethlehem dating from 1287
- Wood as building material exhibits superior thermal properties and structures can be built faster.
- Reduced costs due to quicker construction.
- Structures can still look like ‘normal’ houses, not necessarily like Scandinavian cabins.
Wood houses with a more traditional appearance
- Fire safety issues can be largely mitigates
With good forestry management it’s a no brainer.
