Quality vs. Quantity: The Consequences of Elevated CO₂ on Wood Biomaterial Properties

Synopsis Since the late 1800s, anthropogenic activities such as fossil fuel consumption and deforestation have driven up the concentration of atmospheric CO₂ around the globe by <45%. Such heightened concentrations of carbon dioxide in the atmosphere are a leading contributor to global climate change, with estimates of a 2-5? increase in global air temperature by the end of the century. While such climatic changes are mostly considered detrimental, a great deal of experimental work has shown that increased atmospheric CO₂ will actually increase growth in various plants, which may lead to increased biomass for potential harvesting or CO₂ sequestration. However, it is not clear whether this increase in growth or biomass will be beneficial to the plants, as such increases may lead to weaker plant materials. In this review, I examine our current understanding of how elevated atmospheric CO₂ caused by anthropogenic effects may influence plant material properties, focusing on potential effects on wood. For the first part of the review, I explore how aspects of wood anatomy and structure influence resistance to bending and breakage. This information is then used to review how changes in CO₂ levels may later these aspects of wood anatomy and structure in ways that have mechanical consequences. The major pattern that emerges is that the consequences of elevated CO₂ on wood properties are highly dependent on species and environment, with different tree species showing contradictory responses to atmospheric changes. In the end, I describe a couple avenues for future research into better understanding the influence of atmospheric CO₂ levels on plant biomaterial mechanics.