[GWSG] Corporate pledges; time's up; earth's vital signs; soil C unstable; biochar C stable; soil C sort of stable=C conundrum

[Tilley, Al]

1. “At least a fifth of the world’s 2,000 largest public companies have now made some kind of ‘net zero’ pledge to cancel out their carbon emissions.” Some have made real progress in reducing emissions, though others are at best deferring action and at worst engaging in subterfuge. The urgency of the problem is such that stringent regulation is necessary. https://www.theguardian.com/environment/2021/jul/26/climate-crisis-green-light

2.  How many years until we must act on climate? Four scientists say in a few paragraphs each why the answer is zero. https://www.theguardian.com/commentisfree/2021/jul/28/climate-crisis-zero-fossil-fuels-environment

3. A new report on 31 of the planet’s vital signs indicates that 18 are setting alarming records. https://phys.org/news/2021-07-earth-vital-worsening-humanity-impact.html

4. Soil figures in many carbon sequestration proposals. No-till agriculture and regenerative agriculture in general have been thought to develop carbon-rich humus, fixing atmospheric carbon in fairly stable isolation. In the past ten years humus has been found to readily yield its carbon to microbial activity so efficient that, says the article, no form of carbon in the soil can be assumed to be stable for more than a few years. https://www.quantamagazine.org/a-soil-science-revolution-upends-plans-to-fight-climate-change-20210727/?mc_cid=d13e8c2acf&mc_eid=4a3ab8e4b5

5. Biochar is made by incinerating organic material under low oxygen. It is often said to have great persistence in soil, which it renders more fertile (by acting as a microbe hotel), and to increase carbon fixation. The Wikipedia article suggest why many people are enthusiastic about its potential as a carbon sequestration technology. The article does not identify any successful programs since pre-European contact Amazonian agriculture.  https://en.wikipedia.org/wiki/Biochar

6. A 2015 metastudy found that biochar can persist on a centennial scale and has a positive effect on carbon sequestration. The Wikipedia article claims millennial scales of stability for biochar.  https://onlinelibrary.wiley.com/doi/full/10.1111/gcbb.12266
Is biochar an exception to the claim in item 4 that no form of carbon is stable for more than a few years? If so, is it stable for (at best) a few centuries, as the 2015 article concludes, or for thousands of years, as the references in the Wikipedia article claim? If only centuries, how do we account for the 10% of the Amazon which has been rendered more fertile through biochar buried long before? Perhaps some member of our list will be able to clarify the issue.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.unf.edu/pipermail/gwsg/attachments/20210728/b83f0e5d/attachment.html>