I often hear science-adjacent folks stating that a tree needs to be 30 years old before it starts absorbing CO₂, usually paired with the statement that it’s therefore pointless to start planting tons of trees now for slowing climate change.

Now, as far as my understanding goes, the former statement is very obviously nonsense. As soon as a tree does photosynthesis, it takes carbon out of the air, which it uses to construct cellulose, which is what wood is made of.
Really, it seems like it would absorb most CO₂ during its initial growth.

I understand that it needs to not be hacked down + burnt, for it to actually store the carbon. But that would still mean, we can plant trees now and not-hack-them-down later.

I also understand that some CO₂ invest may be necessary for actually planting the trees, but it would surprise me, if this takes 30 years to reclaim.

So, where does this number come from and is it being interpreted correctly? Or am I missing something?

Edit: People here seem to be entirely unfamiliar with the number. It might be that I’ve always heard it from the same person over the years (e.g. in this German video).
That person is a scientist and they definitely should know the fundamentals of trees, but it was usually an offhand comment, so maybe they oversimplified.

  • @FlowVoidEnglish
    1•1 year ago

    Probably because the writer is not reporting her own original research. She is reporting work done by others, they often used metric, and any metric units were converted to common US units because the article was intended for a general American audience.

    And why isn’t there a button to restore the original metric units? Same reason why when a newspaper reports a translated quote from Macron or Putin or Xi, there is usually no button to restore the original French or Russian or Chinese: the editor decided that it wasn’t necessary for the intended audience.