• Pohl@lemmy.world
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      10 months ago

      And they are correct. A fast growing conifer (like all trees) is made out of carbon fixed from the atmosphere. When it dies and is allowed to rot, the carbon is released back into the atmosphere. A tree is, over its life, completely carbon neutral.

      Cutting a tree and putting it in an anaerobic landfill where it cannot rot, removes carbon from the atmosphere. The tree farmer plants another fast growing tree in that spot and in a few years you repeat the process.

      It is a form of carbon sequestration. Albeit a very slow and haphazard one. If you want to use trees as part of a climate strategy, this is what it looks like. Grow > cut > bury.

      • activistPnk@slrpnk.netOPM
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        10 months ago

        I’ve heard that young trees don’t gain much. One form of greenwashing is to plant trees, take credit for planting a tree, then not tending to it to ensure it’s established over the long term. The trees end up dying before they get big enough to pay off. Many of them also get cleared deliberately to repurpose the land (and why not when the carbon credits don’t involve a followup check?). So in the context of Christmas trees, aren’t they getting cut down quite early in their life for the purpose of fitting in living rooms?

        BBC World Service keeps talking about Christmas trees today, and I just catch the end of the story but they say the farming is vastly non-organic.

        Perhaps this is crazy talk, but would it make sense to cut the top ~1—2 meters off a quite large wild pine tree to use as a Christmas tree, cover the wound with tar, and let the rest of the tree live on?

        • Pohl@lemmy.world
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          10 months ago

          There is very much a conservation of matter thing here that you have to consider. The dry weight of a tree, no matter age or size, is almost completely carbon fixed from atmospheric CO2.

          The only thing that would matter for tree age is the rate of carbon fixation is probably not linear with age/size. I’m not sure how well studied that is for the specific pine/fir species that we use in this application.

          Either way, even if you cut your grass and stored in an anaerobic env you would be doing some small amount of carbon sequestration.

          Re: greenwashing, all trees are carbon neutral over the life of the tree. If they die in a year, neutral; if they life for a century, neutral. Planting trees is not a carbon solution. You either have to bury dead trees or stop digging up millennia old dead trees (and algae). Those are the only two options. Every thing else is just for show.

          • Five@slrpnk.net
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            10 months ago

            It sounds right in theory, but you have to consider the planting and transportation costs. Plants that grow for longer absorb more carbon, and the petrol cost associated with tractor tilling, planting, spraying pesticide and fertilizer are proportionally lower compared to the volume of carbon absorbed by growth. Claiming buried evergreen trees are carbon sinks ignores all of the carbon set-up costs associated with establishing the trees. I’d believe it if we made tannenbaum out of bamboo and algae, but I’d have to see more data to believe Christmas tree growth was a carbon sink.

            Moving it from the tree farm to the city, store to home, home to waste collection, waste collection to landfill is another practical carbon release. Landfills are real-estate, also a limited resource. While material decays much more slowly, preserving carbon not the intention of landfills. Modern landfills do account for or encourage the release of decay gasses and burn them off or tap them for power. They release the carbon dioxide is slower than incinerators (the much more likely destination for used trees) but probably not on a slow enough scale to make a geological impact.

            You are correct that tree growth is carbon neutral, and something additional must be done to prevent decay and sequester the carbon. Simply growing trees to maturity and then sequestering them as bio-char on-site is more likely to result in net sequestered carbon.

          • activistPnk@slrpnk.netOPM
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            10 months ago

            Surely that must be a quite unpopular view. There are so many tree planting efforts. If that’s a sham (i.e. not carbon negative as advertised), why isn’t this getting a big spotlight? Ecosia is advertising they plant trees proportional to the number of search queries they get. And people buy into that.

      • meyotch@slrpnk.net
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        10 months ago

        That’s really all the biochar people are on about. They just get to double dip by directly sequestering the carbon in the soil and there can be long term benefits to the soil too, properly done.