Microblog Memes

The only carbon sequestration that makes any sense is small-scale, on-site or local (so you can avoid transport) biochar production via retort.

--> Biochar if you're not familiar is similar to charcoal, it's a form of "carbon black" that is elemental (isn't going to decompose or oxidize and contribute to climate change) and when added to soil helps plants (by acting as a sponge for water, nutrients, bacteria) while sequestering carbon for millennia in the soil.

For example, a landscaping company that burns it's waste to fuel a biochar retort and then using the resulting biochar to amend the soil used in the landscaping operations. (Think in cycles)

--> A biochar retort is form of furnace or fire pit that uses the flammable gasses produced by pyrolizing organic materials to fuel itself.

--> Pyrolysis is decomposition of organic material with high heat and no oxygen. It produces gases like methane which are burned in the retort producing particulates, CO2 and water (and that carbon does go back into the cycle) and leaves behind large amounts of elemental carbon black that is not going to contribute to climate change.

Sequestration by millions of backyard gardeners and little landscaping companies doing a little is better than trying to do it on a large scale because the large scale requires (as you note) resources. Hundreds of engineers and architects and workers driving to work for years so they can design and build a large device made of metal (that had to be mined, smelted, and shipped) and likely has an accompanying parking lot and office building would take years to break even sequestering as much carbon as it took to design and build it.

Sequestration as I describe here doesn't require much. For example, I make biochar using coffee cans in my fire pit .

Q: But won't burning some of the waste in the retort to heat the biochar contribute to climate change?

A: Any carbon in landscaping wastes, unless sequestered, is going to decompose into carbon dioxide (e.g. composting). Burning doesn't add any extra carbon, it's just that burning is a faster reaction than composting (but both burning and composting are part of the short term carbon cycle, biochar is not) . But because this burning is done to fuel pyrolysis it's part of an efficient process.

The real danger from burning the waste is particulate pollution, but that could be controlled with common scrubbers tech.