Talk:Soil carbon sponge

toned down carbon sink sales pitch

This is about a recent edit. I toned it down because, for one, Walter Jehne sees the carbon sink role an accessory to the ecohydrology role of the soil carbon sponge. But beyond that, an over-the-top sales pitch risks misrepresenting the current status of the science: researchers are identifying a growing number of mechanisms that result in the faster release of soil carbon as CO₂, but these naturally occurring processes are not accommodated in Earth System Models (ESMs). This started with Ponomarenko (2000) pointing out that charcoal dominates the SOM in some black soils but there is no way to accommodate that scenario in current models. It picked up steam with Lehmann's 2015 article in Nature debunking the presence of polysaccharides thought to be a sink of resistant soil carbon resulting from humification. A Soil Science Revolution upends plans to fight climate change is a good introduction to the shifting understanding. A lot of folks are playing catchup with these changes. Paleorthid (talk) 21:39, 21 March 2022 (UTC)

Is this article accepted knowledge?

"Soil carbon sponge" is Walter Jehne's phrase. Is he in fact a climatologist - source? Is he in fact a microbiologist, or (though he so describes himself) a scientist? Jehne's early-career thesis on woodland soils is or was available online, and he co-authored Walker, J.W., Thompson, C.H. and Jehne, W. (1983) "Soil weathering stage, vegetation succession, and canopy dieback": Pacific Science 37, 471–481, as a CSIRO (Aus) staffer, but left CSIRO the following year after 15 years, see https://www.abc.net.au/news/2017-11-30/interview-with-walter-jehne/9206054. He co-authored an apparently not-peer-reviewed discussion paper "METHANE Sources, Sinks and Uncertainties": Peter Bruce-Iri, Max Purnell, Walter Jehne, Thorsten Arnold, Alfred Harris October 2021. This reads as a polemic against the New Zealand government's livestock methane reduction proposals. His 2018 paper "Regenerate Earth" reads like an opinion paper or lecture and is not primary or secondary research, a scientific paper or a literature review or synthesis. Other publications and videos suggest that he is a possibly professional advocate for a set of claims and beliefs about soils, agriculture, carbon and the climate, that may run counter to accepted knowledge. This source https://mullooninstitute.org/team-member/walter-jehne/ states, "In 2017 he took part in an invitation-only United Nations Food and Agriculture Organization conference in Paris aimed at bringing soil into the next Intergovernmental Panel on Climate Change (IPCC) report." However, neither the name Jehne nor the phrase "soil carbon sponge" currently appears in any of the IPCC's many 1000s of published pages according to a site-specific Google search of ipcc.ch. The central thesis of Jehne's "Regenerate Earth" publication is that the world community can, should and must "Draw down up to 20 billion tonnes of carbon annually back into our soils" via photosynthesis. Is this currently supported by accepted knowledge? One of the article's sources - Melillo, Jerry; Gribkoff, Elizabeth (2021). "Soil-Based Carbon Sequestration" - states, citing a 2019 scientific paper, "Scientists have estimated that soils—mostly, agricultural ones—could sequester over a billion additional tons of carbon each year." This is not 20 billion. See also https://en.wikipedia.org/wiki/Regenerative_agriculture#Criticism. Jehne appears to be associated with a number of advocacy organisations. He appears in over 100 YouTube videos from the past ten years as a presenter. This and other Web evidence suggest that his principal recent occupation, or part of it, is that of advocate and international public speaker. The only more-or-less independent source, i.e. outside of advocacy organisations, on "soil carbon sponge" that I have found is "Rainwater Harvesting for Drylands and Beyond, Volume 2" by Brad Lancaster, which is not a scientific publication but a popular-style 'how-to' book by a practitioner and influencer, and cites works by Jehne as sources. It is important that articles relevant to climate policy and actions are reliable and accurate. It is arguable that the Soil_carbon_sponge article does not meet Wikipedia's standards. Should it be deleted? AdNico (talk) 15:46, 28 October 2025 (UTC)