OCKHAM’S RAZOR & the FOREST CARBON CONUNDRUM
William Ockham was an English Franciscan friar and philosopher born in 1287 in Surrey, England. He lived only 62 years and died , it is believed, from the black plague in about 1247. He advanced and further developed Aristotle’s minimalist philosophy and gave it a moniker- “Ockham’s Razor”. Like Aristotle, William Ockham also promoted the principle of simplicity and advocated for the removal of unnecessary hypotheses- the Razor. Re-iterating the best solution is the simplest and all other hypotheses are unnecessary; the simpler solution of a problem is always preferred. This principle is often expressed as “hypotheses are not to be multiplied beyond necessity.”
Global CO2 emissions in 2024 reached a record high of 41.6 billion metric tonnes, nearly a 1% increase and consistent with an upward trend. The burning of fossil fuels alone accounted for about 37.4 billion tonnes.
Fostering sustainably managed forests on a global scale is the simplest solution to sequester and store excessive carbon emissions. It is indeed Ockham’s theory in practice. The best resolution to any problem is the simpler one. Other more complex and perhaps more costly solutions are ‘razored’ from the hypothesis and cast aside as superfluous and irrelevant.
Global forests, led by temperate forests can sequester about 16 billion tonnes of CO2 annually. Which begs the question: how much could they sequester and store in a managed forest where larger diameter, older age classes are well represented and younger age classes are managed with an appropriate species mix and early stand treatments ? If these age classes were managed across the landscape in a mosaic consistent with Protocols and Guidelines defined in the Global Forest Resources Carbon Registry and Forest Plan, does it make a substantial difference in the potential of forests to sequester and store carbon? Yes, it apparently does. The following graphic is taken from field inventory data and modelled with the globally accepted Forest Vegetation Simulator software (FVS).
The illustration supports the hypothesis that sustainably managed forests have the capacity to nearly double the carbon storage and sequestration potential of global [temperate] forests. The key strategy is a managed and balanced age class distribution across the forestscape. Younger age classes managed with early and appropriate silviculture treatments have a higher sequestration rate but a lower storage capacity. Older age classes have a greater storage capacity but a significantly lower sequestration rate. And overlying this disparity is the complex issue of gross versus net productivity.
The decline of the unmanaged forest in the graph reflects many factors. As stand structure and stocking near capacity, disturbance regimes become a significant influence on forest development. Fuels accumulations, wildfires, diseases and insects, forest succession, and climate risks become relevant risk factors. However, silviculturists manage these risks with prescriptive treatments. Likewise, the increasing productivity of the managed forest stems from building and maintaining stand structure, forest structure, and age class distribution as well as adapting forests to climate change with the application of appropriate silviculture treatments.
Figure 1. Potential carbon sequestration in a managed and unmanaged forest over an appropriate time frame.
The conundrum, the paradox, the irony of this effort to manage carbon emissions using forests as a carbon capture and storage mechanism may be the utter failure of social structures and cultures around the globe to manage forests sustainably. Which merits the $64 question: has global societies failed the profession of Forestry by not demanding anything other than a cheap 2 x 4 or has the profession of Forestry fail these global social structures by not delivering anything other than a cheap 2 x 4? It is worth recalling that the number one use of woody material around this planet is for heating- fuel for the cooking and heating fires. And then there is that.
Carbon registries typically address the issue of sustainability with the notion of ‘leakage’. Leakage is the conjecture that committing a forest to carbon will decrease the available timber to harvest for traditional forest products- lumber and plywood for building. And because of this decreased availability- this perceived ‘loss’ of timber, the lumber industry will be forced to log adjoining areas unsustainably to substitute for this loss. Addressing leakage in this manner is a subtle admission from the timber industry and resource management agencies across jurisdictions that are not now and have never promoted ‘sustainable forest management’. And then there is that.
There are three take home messages from this graphic example: firstly, we can amass huge carbon accumulations with the application of appropriate silviculture; secondly, this did not happen over-night. This was the result of a long-term commitment to a management plan, prescriptive silviculture, and the construct of forestry; and thirdly, we cannot ‘park’ a forest in a carbon project and expect it to stay healthy and productive.
Edward Mann
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