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Comment by tomsyouruncle | Hacker News Reader

Maybe the concern others are expressing here can be thought of as the risk of double counting of carbon.

If I run an industrial plant that's currently fuelled by burning waste lignin from the paper industry, and I decide to stop that and install some solar panels instead, it seems reasonable for me to claim that change is carbon negative (i.e. I've reduced carbon emissions).

Now if CarbonCrusher comes along and buys the lignin I no longer need, uses it to build a road, and claims the same carbon saving as I did, we end up double counting.

Which of us is wrong?

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This is a very fair question. We need to be mindful going forward in how we communicate. We can say that our Scope 3 emissions are negative, but scope 1 we are slightly positive (but still much lower than competition) Just to clarify; we go from 7-10kg CO2 positive for traditional methods, to 5 kg negative in two steps; Step one is we reduce emissions from transport, extraction etc because we have a better Crusher which recycles the road better, which takes us to just above 1kg pr m2 - massive savings already from the traditional method, and this could be counted mostly in Scope 1 or 2, some of it in 3 (reduced extraction). The remaining ca -6 kg is the effect of lignin - here debated in the thread and that we are saying is carbon negative. This is a scope 3 effect.

Thanks for pointing out! We are still a young company and need to work on our Scope 1-3 accounting :)

Thanks a lot for adding these details about scoping[0]. I’ve definitely learned something there.

So my scope 1 emissions can be your scope 3 emissions if I emit carbon to make something that I sell to you… but the “real” emissions are always _somebody’s_ scope 1. Interesting stuff!

[0]: https://www.carbontrust.com/resources/briefing-what-are-scop...

You're switching contexts.

When you switched from burning lignin to solar, you reduced your carbon usage.

However, what happened to the lignin that you stopped using?

If it was burned somewhere else, the total carbon usage remained the same even though you changed your usage.

If it was stockpiled and is now decomposing over three years, the carbon usage was time-shifted and will be back where it was in three years. (However, total carbon usage will be reduced the first and second year.)

This is supposedly a usage of lignin that results in no release, so it actually is carbon-negative (assuming that the processing doesn't use more carbon), regardless of what other folks think that they did. That said, it's probably actually just time-shifted, albeit on a long time-scale.

Note that both coal and diamonds are actually time-shifted carbon usage, on the scale of millions of years.

This is exactly my point (the after 3 years if it decomposed you are just time shifting) which is why I asked how long the roads take to decompose and what they translate into. Sooner or later that lignon in the road will become C02. But is that in 10 years? 100? If its time shifting it only by 15 years or so then its NOT reducing the total carbon to the atmosphere, just temporarily storing it. No different than putting the lignin in a warehouse for 15 years before burning it. So to call that carbon negative is just... bad math at best.

> When you switched from burning lignin to solar, you reduced your carbon usage. However, what happened to the lignin that you stopped using?

In my scenario, CarbonCruncher bought the lignin I stopped using and made a road out of it. Crucially, in doing so they claim to have a negative carbon impact because they'd trapped that carbon in the ground. But I already claimed that impact when I stopped buying and burning it myself and switched to a zero-emission energy source.

So my (genuine) question remains: we can't _both_ claim the benefit, so who's right?

What's the relevance of "claim"?

Thousands of people get "best grandma" coffee mugs each year. Logically, only one of them actually is, but who cares and why?

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