I am extremely appreciative of David Atkins’ effort to delve into the complicated area of forest carbon in this piece at TreeSource. I actually asked several scientists if they knew of a paper that outlined the different assumptions and conclusions, and discussed the area of disagreements.. maybe someone out there knows of one? Otherwise, you have to wonder why that would not be the most important kind of paper to write..Here are the areas of disagreement, here is why, and here is what we need to do to find out more. If we are going to use science in policy, wouldn’t that be the most important kind of investigation to conduct?
It’s not the universities’ job though, here’s what Acting Dean Davis of OSU says:
“Researchers often explore extremes of a subject on purpose, to help define the edges of our understanding; or other studies might only examine one aspect of an issue which in reality does not occur in a vacuum. It is important to look at the whole array of research results around a subject rather than using those of a single study or publication as a conclusion to a field of study.”
That might be difficult for policy makers to do unassisted, and I wouldn’t blame them for throwing up their hands at what appears to be an arena of scientist gladiators.
I think it falls to government to address these policy questions, through research designed as Peter Gluckman describes here.
But how could researchers come to such wildly different conclusions on the carbon effect of wood products? This led me to a series of interviews and multiple other sources to sort through a rabbit warren of questionable assumptions and conclusions in the OSU researchers’ paper.
Make assumptions with care
Did the scientific process break down in the review – or lack of review – given this paper and its assumptions and conclusions?
The problems that surfaced in the Law paper include:
* The quote used by Oregon Wild can’t be found in the references cited.
* The calculation used to justify doubling forest rotations assumes no leakage. Leakage is a carbon accounting term referring to the potential that if you delay cutting trees in one area, others might be cut somewhere else to replace the gap in wood production, reducing the supposed carbon benefit.
* The paper underestimates the amount of wildfire in the past and chose not to model increases in the amount of fire in the future driven by climate change.
* It assumes a 50-year half-life for buildings instead of the minimum 75 years the ASTM standard calls for, which reduces the researchers’ estimate of the carbon stored in buildings.
* It assumes a decline of substitution benefits, which other LCA scientists consider as permanent.
* It models just one species of insect to account for tree mortality when there are a variety of insect and diseases which impact forest carbon capture and storage. And the insect mortality modeled was unrealistic.
* The OSU scientists assumed wood energy production is for electricity production only. However, the most common energy systems in the wood products manufacturing sector are combined heat and power (CHP) or straight heat energy production (drying lumber or heat for processing energy) where the efficiency is often two to three times as great and thus provides much larger fossil fuel offsets than the modeling allows.
* The researchers claim to conduct a Life Cycle Assessment (LCA), but fail to use the international standards for conducting such analyses, without explaining this difference in methods.
* The peer reviewers did not include an LCA expert.
* The claimed significance of substantial carbon savings from delaying harvest and the large emission numbers from the forest products sector are undermined by all of the above.
I think the pros and cons of the different assumptions might be an interesting conversation to have on this blog. And we could perhaps use this blog, if scientists were interested, as a forum for extended peer review.