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Comment by quixoticelixer- | Hacker News Reader

> Today's cost of atmospheric carbon capture is several hundred dollars / ton.

For stuff like direct air capture, not for afforestation.

Same issue of "honesty" with afforestation-based credits. A ton of carbon removed during the growth of a new tree is not equivalent to a ton of carbon already removed today.

However, as these types of projects actually do remove carbon, one could probably compute an adjustment factor and purchase additional credits to achieve an "honest" offset.

That's assuming the afforestation is even helpful and not one of the various examples of incentives for planting trees leading to work that's actually doing more harm than good.

Out of all the nebulous carbon offset schemes that exist today, afforestation seems to be one of the least scammy options if ones adjusts for the fact that "future value" != "present value". Even the uncertainty of the long-term success of afforestation projects can be statistically modelled and incorporated into an adjustment factor. However, nobody is going to willingly do that, so even those types of offsets will remain dishonest.

Absent regulation, carbon offsets are a race to the bottom in producing the cheapest "offset" just hovering above the threshold of "fraudulent".

Direct air capture with long-term sequestration, performed prior to the sale of a carbon credit, is the only scheme that is remotely close to being fully honest.

I am very dubious that afforestation won’t be logged or burned at some future date, which I assume is what you refer to as the “long term success” of these.

From what I’ve seen people tend to be happy to take the money and they just burn it next year.

That's an interesting comment. I hadn't really ever considered that afforestation might be a bad thing - always just assumed "more trees = good". In what sort of examples would it be a bad thing? Trying to create forests in places that naturally weren't forests in the past?

Right. For instance, one story I read concerned disturbing grasslands in order to plant more trees — foolhardy because grasslands themselves are excellent carbon sinks and the trees would take a long time to be comparable. Others concerned trees being planted with little possibility of survival. I believe the first was in China and the second in Turkey if anyone wants to dig through news archives and try and find these stories again.

Obviously the problem here is people just setting “trees planted” as the metric because it’s easy to count and creating perverse incentives.

Factor in that the carbon is only captured so long as the forest survives. If the forest burns or the trees fall and rot, the carbon is returned to the atmosphere unless and until new trees grow.

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