Official Luthiers Forum!

Some thoughts on an early Monday morning after I returned from an earth science conference in which much was made of deforestation and carbon emissions (rightfully so). During one session of this conference, lumber use (i.e. logging) got a very bad rap when it came to carbon emissions, because (as is well known) trees remove CO2 from the atmosphere - and add oxygen - as long as they are alive. But I decided to do some research of my own this morning to check their numbers when it came to logging.

To start:
Total global forest cover = 3,869,455,000 hectars or 3.87e+13 square meters as of year 2000 (http://www.mongabay.com/general_tables.htm)
Annual forest growth = 500 grams/square meter on average (http://www.rff.org/documents/RFF-DP-97-37.pdf)
When multiplied by global forest cover, annual forest growth = 1.94e+16 grams/yr.

Annual global deforestation = 7,317,000 hectars or 7.32e+10 square meters annually during 1990-2005 (http://rainforests.mongabay.com/deforestation.html)
Average growing forest density is 800 grams/square meter so:
Annual global deforestation = 5.85e+14 grams/yr.

Average annual global lumber harvest = 53 grams/m2 (http://www.rff.org/documents/RFF-DP-97-37.pdf).
When multiplied by the rate of deforestation we get:
Annual lumber harvest = 3.88e+12 grams/year.
This assumes that lumber is harvested uniformly from all areas that are being deforested - so it is probably an overestimate of the amount of timber that is being converted into lumber, because hauling logs from forest to sawmill requires roads (but agricultural deforestation does not).

OK - (drum roll) - so the annual production of lumber (3.88e+12 grams/year) is 0.66% of the total mass of forest that is being cut down on a yearly basis. And this is probably an overestimate. This means that something like 99% of the world's forests are cleared for agriculture or ranching - meaning, the wood is burned.

Interestingly, the proportion of forest cleared by logging (estimated above) is at least 10-20X less than estimated by one environmental group (http://rainforests.mongabay.com/0803.htm).

Burning of wood releases ~1000 kg of CO2 per cubic meter (dry). So for each guitar you make (1-2 board feet per instrument) you keep 3-6 kilograms of CO2 out of the atmosphere (so please do not burn your guitars when you're done with them!).

Commentary welcome.

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The member formerly known as erikbojerik....

Eric,

Very interesting results.

I think if you looked for the "Major Culprit" in the "Developed world" -- it would be pulp wood.... Not sure where Plywood, OSB, and the like roll out... but I don't think they are considered with lumber. Trees harvested for paper products and such. In the "3rd World" -- much of the wood is harvested for Firewood for cooking and heating or cleared for Agriculture... and it truly is a shame to see what happens. They just cut the trees, pile them up, and burn them.

You are right... especially here in the USA -- Many trees are cleared for building and landscaping and never even lumbered. Mills aren't interested in "Yard wood" and Developers aren't interested in fooling with Loggers... so they just plow up the trees and burn them or send them to the dump.

In the end, I think we still "Net" forestry growth rather than depletion because of active replanting and plantation efforts... The trouble is that the trees I want for tops, Backs, and Necks are Big and Clear -- meaning Old Growth... or possibly Second growth after logging that happened 200 years ago.

Thanks

John

I believe the Sohngen et al. paper lumps both "lumber" and "paper" utilization into their term which they call "harvest". So the numbers should include both.

Yeah - my numbers are global averages, but when you break it down by individual continents things get more variable.

In North America there is indeed net growth of forest cover, due mainly I think to smart management. Not so in Central/South America and Africa where slash & burn dominates.

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The member formerly known as erikbojerik....