The carbon from the trees is now not in the atmosphere, it's in the wood components, and won't be in the atmosphere until the wood components reach end of life and are burned/rotted/whatever.

So yes, carbon has been removed from the atmosphere. I don't understand the objection.

If X amount of carbon was in the trees, X amount of carbon is now in the building materials (at best). There's no further removal of carbon from the atmosphere by this alone. And all of the future carbon the trees would have sequestered is now not going to be sequestered by those trees. So more likely carbon positive than negative.

> The space the trees were in will now have more trees grown in them.

That's an assumption. And even if it were true, those trees would take years to begin to sequester the same amount of carbon that the previously existing trees did. And even then, it's not obvious that those new trees would sequester more carbon than the previous trees would have had they been allowed to continue growing.

Plus if you're going to say that building with blocks is carbon negative, you're going to have to talk about how those trees get turned into blocks, and how the overall process including that, is somehow carbon negative.

It sounds like you might be making a stock vs flow error here. Or I could be misunderstanding you.

> And even then, it's not obvious that those new trees would sequester more carbon than the previous trees would have had they been allowed to continue growing.

1. Trees slow as they grow (after a certain point).

2. Commercial tree farms exist to grow trees. If they weren't growing trees for consumption, something else would be done with that land.

Yes, for example let the natural vegetation take over, increase biodiversity, and sequester more carbon thanks to the increased biodiversity and better soil than fucking tree farms.

- A lot of the time plantations are planted on less productive farmland. - Not all plantations will naturally regenerate quickly back to native vegetation.

- Those trees were planted for a reason and a lot of plantations are planted on degraded farmland or scrubland.

It's a very safe assumption

And we’re already doing this for centuries - using wood for making buildings - so we’re merely continuing the status quo, not magically putting more carbon away suddenly.

You're ignoring material waste. This process doesn't consume 100% of the tree; only a portion of the tree's carbon is sequestered into the building. The rest is rotting.

> The space the trees were in will now have more trees grown in them.

Trees are renewable, but it's not quite "copy&paste". Further, the harvesting of the trees was certain to be carbon intensive.

So, on the whole, you can trust this process IS NOT CARBON NEGATIVE.

What it may be is LESS CARBON INTENSIVE than a traditional process. They are VERY FAR from crossing the neutral line and yet are trying to claim carbon negative? That's pretty brash.

Does the objection make more sense now?

> You're ignoring material waste. This process doesn't consume 100% of the tree; only a portion of the tree's carbon is sequestered into the building. The rest is rotting.

It's ply. Apart from the root system, it's quite close to 100% indeed.

> Trees are renewable, but it's not quite "copy&paste". Further, the harvesting of the trees was certain to be carbon intensive.

Tree harvesting is pretty much fine. Transport is what pollutes the most here. The new growing trees are carbon sinks. It's not a question of renewability. It's just that you used to have CO2 in the air and now it's a house. Processing will mostly use electricity so it depends of how your local electricity is produced of course.

> They are VERY FAR from crossing the neutral line

They are probably not very far. It's not an heavily mechanised project. Assembly is mostly done by hand. Considering the amount they sequester, being neutral is not that far fetched.

I disagree on your accounting (largely because the house is torn down one day and further a CNC throws wood dust everywhere and this project requires one front and center), but none of that matters. Carbon negative is a strong claim that requires strong evidence. Of which, none has been offered.

Is it, though? Because operations I've been to use every last available ounce of the tree. Trunk and limbs are sawn, small limbs, branches, bark, and offcuts are ground for biomass heating. Yes, it's burnt, but releasing no more carbon than it captured in its lifecycle and to provide a tangible end result that would otherwise be achieved with fossil fuels.

Root stumps rot, yes, but providing a breeding ground for insects and hence birds and small mammals and hence predators. They also fix soil beneficial bacteria and fungi, and having spent all their energy breaking up the soil and then breaking down they prepare the best soil bed for the new tree to take its place and sequester more carbon.

It's not the perfect process, by any means, but wood as a building material is infinitely more sustainable than concrete, gypsum and stone.

Cool, show me the part where any of that means this company has a right to claim carbon negative?

Onus isn't on me here.

I just pointed out that your emotional response that backs your argument isn't necessarily reflective of what actually happens.

But I mean, if we want anything to be carbon negative we need to capture carbon from the atmosphere and put it somewhere; e.g. reclaiming land for forests or putting carbon back into the ground where we got it from, but putting carbon in constructions as part of the solution, why not? For dealing with climate change, the important part is getting it out of the atmosphere.

I'm not sure what "upfront" means here, but it makes sense if talking about overall net CO2 usage. The amount of CO2 in the atmosphere after building would be 17T less than before the tree started growing. Ie the tree absorbs 17T more during its growth than is emitted during harvesting, transport and construction. Whereas an equivalent brick building puts 30T more into the atmosphere than the (unharvested) tree absorbs.

1) The wood the house is built with will not be there forever, some day the house will be torn down and the wood burned or rotten

2) Cutting down trees and planting new ones is not a good way of carbon sequestration. Otherwise, why not cut down all trees and just plant new ones? Bam, carbon negative, climate problem solved.

People need to understand that trees should not be seen as a renewable resource in the context of climate change. Not for building, not for burning as fuel.

Another thing worth considering is that building small houses uses a lot of land, land which might have had forests. That needs to be considered too.

This carbon negative claim taken to the extreme would mean, that we should just cut down all trees and plant new ones. I think you can see why this is ridiculous?