Mass timber’s pitch has always had two halves. The first half, that wood stores carbon and steel and cement emit it, is solid. The second half, that there will be enough wood, is the one nobody stress-tests.
Reuters reported on Sept. 9 that global wood demand is projected to grow 37% by 2050, and that roughly 6.88 million hectares of forest have already been lost this year.
Where the losses are coming from
Agriculture is still the main driver of permanent deforestation. Wildfire accounted for about 30% of tree cover loss and logging roughly 25%. Those shares matter for construction, because only one of them responds to procurement decisions.
A specifier choosing certified glulam over a steel frame does nothing about soy expansion or a fire season in British Columbia. What that specifier does affect is whether demand growth gets met from managed working forests or from marginal supply nobody is tracking.
The substitution argument, honestly stated
Reuters notes the 37% figure could go higher if wood displaces more steel and cement in buildings as a climate strategy. That’s the uncomfortable version of the mass timber thesis: the better it works, the more pressure it puts on the resource.
This doesn’t make mass timber a bad idea. Life cycle work keeps showing meaningful embodied carbon reductions, and recent structural analysis has found steel accounting for 19% of a building’s mass and 64% of its embodied carbon. The numbers favor wood where wood works.
It does mean the industry should stop treating supply as infinite and certification as proof. FSC or PEFC on a submittal tells you a chain of custody exists. It doesn’t tell you whether regional harvest is running above growth.
What to actually ask a supplier
Where is the fiber from, at the region level, not the country level. What’s the growth-to-drain ratio in that region. Is the mill sourcing from plantations, managed natural forest or salvage. Salvage volumes from fire-killed timber are rising and are genuinely additional, at least until the standing dead runs out.
Those are answerable questions. Most projects never ask them, and the ones that do tend to get better wood.