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Comment by BrainVirus | Hacker News Reader

>Plants use the atmosphere carbon to grow and that carbon is then released when the plants die and is decomposed.

Plants do not melt into thin air when they decompose. They compost, become part of the soil, feed bacteria, fungi and other plants. Some of these processes release various gases, but it's nowhere near 100% conversion. If it was, there would be no fossil fuels to begin with.

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Yes, but most plants we currently have are in a pretty much 100% cycle, that is, why the biosphere is so stable. Take the Amazon region, the top soil layer is like 50cm. There is no deposit of carbon into the ground going on and its one of the most lush growing regions. To have a net carbon capture, the decay of dead plant material needs to be cut down by at least an order of magnitude. The article names options for that.

Note: from what I read, our fossil fuels come not from a constant process but from certain times in the past where the natural cycling of e.g. wood was way less than 100% which created concentrated deposits of carbon. Which makes sense if you consider how concentrated they are, if it was a truly steady process, they would be much more spread out.

Fossil fuels largely come from the Carboniferous period. The reason for this is that during this period the trees which covered the planet's surface did not decompose, and became buried in thick layers, which became coal seams. Whatever the reason, we know that the carbon cycle was not so much of a cycle at this point--the fixed carbon was retained and not recycled back into the atmosphere, resulting in the accumulation of vast quantities of carbon.

In the current environment, breakdown is rapid and carbon is rapidly recycled. Accumulation is minimal and while some longer-term storage can occur in places such as peat bogs, these are not stable long-term stores--they can easily burn if they dry out.

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