In 2024, the voluntary agricultural carbon credit market contracted sharply, from $84.9 million down to just $36.1 million — a 57 percent collapse driven largely by buyers losing confidence in whether the credits they were purchasing represented real, verified carbon in the ground. At the same time, investment in digital monitoring, reporting, and verification technology for soil carbon surged to $2.3 billion, as an entire industry scrambled to build cheaper, faster, and more trustworthy ways to prove that a given patch of farmland was actually storing the carbon it claimed to be. Nobody in that scramble appears to have looked underground at a signal that’s been sitting there the whole time: mycorrhizal fungi, the microscopic networks responsible for funneling a genuinely enormous amount of that carbon into the soil in the first place, generate their own measurable electrical activity — and researchers studying that activity for entirely unrelated reasons have found it responds to environmental conditions in ways that might, in principle, be readable.
The Scientific Foundation
Two largely separate bodies of research sit at the heart of this idea, and as of today, nobody has formally connected them. The first is mycorrhizal biology’s role in soil carbon: research led by scientists including those cited in a 2026 arXiv paper on fungal biodiversity monitoring estimates that plants allocate roughly 13 billion tons of CO2 to mycorrhizal fungal networks annually, making these networks one of the largest single entry points of carbon into terrestrial soil systems. A landmark 2026 Science paper mapped the global density and biomass of arbuscular mycorrhizal fungal networks for the first time at scale, while other recent research has proposed a “Hyphal Carbon Transfer Theory,” suggesting fungal hyphae actively transport plant-derived carbon from the root zone into more stable, long-term soil environments rather than that carbon simply diffusing there passively.
The second body of research, developed almost entirely independently, is fungal electrophysiology — the study of electrical signals fungi generate on their own. Since Andrew Adamatzky’s foundational 2018 paper on oyster fungi, published in Scientific Reports, researchers have documented that fungal mycelium generates action-potential-like electrical spikes, detectable with differential electrodes inserted directly into a growth substrate or fruiting body. A 2022 paper in Royal Society Open Science analyzed this spiking activity across four fungal species and found spike characteristics were species-specific, with durations ranging from one to twenty-one hours and amplitudes from 0.03 to 2.1 millivolts. A January 2026 study using a star-shaped electrode array on oyster mycelium found this electrical activity is directionally structured and burst-based, propagating slowly across different spatial regions of the fungal network over timescales of seconds to hours — behavior the researchers describe as a spatially extended, excitable biological system distinct from anything modeled in neuroscience.
The Cross-Domain Connection
Here is where the idea is genuinely speculative rather than an established finding: no published study has tested whether these fungal bioelectric signals correlate with, or could serve as a proxy for, actual carbon flux or sequestration rates in soil. But the pieces that would need to connect are each independently well-established. Fungal electrical signaling researchers have already found that fungi respond measurably to mechanical, chemical, and optical stimulation by changing their spiking patterns — a 2025 paper found electrical activity in mycelium correlated with fungal growth rate and varied in response to biocide treatment, suggesting these signals do track real physiological and metabolic state changes, not just noise. Since mycorrhizal fungal growth, hyphal extension, and metabolic activity are the literal mechanism by which carbon moves from plant roots into stable soil pools, a sufficiently sensitive electrode array embedded in agricultural or forest soil could, in principle, be listening directly to the biological process responsible for carbon sequestration as it happens — rather than inferring it indirectly through soil sampling, remote sensing, or computational modeling, which is how virtually all current carbon credit verification actually works.
That indirect-inference problem is precisely what’s driving the current MRV credibility crisis. Current soil organic carbon monitoring falls into three categories, according to a 2026 review: expensive direct soil sampling, cheaper but less accurate carbon modeling with uncertainty ranges of plus or minus 20 to 40 percent, and remote sensing approaches that still require ground-truthing against physical soil samples. A 2026 Science review of a dozen carbon crediting protocols found meaningful methodological differences that create real risk of nonequivalent credit creation between projects claiming similar carbon storage — exactly the kind of inconsistency that erodes buyer trust. A cheap, continuously monitoring, direct biological signal embedded in the soil itself is the kind of tool this field has been actively searching for.
What Remains Undemonstrated
This needs to be stated plainly: this is a proposed research direction, not an existing technology, and treating it otherwise would be dishonest. No study has measured whether fungal electrical spiking rate, amplitude, or pattern actually correlates quantitatively with carbon transfer volume through a mycorrhizal network. The fungal electrophysiology field itself is young enough that a 2025 FEMS Microbiology Reviews paper described “past and present challenges” in even standardizing how these signals are detected and interpreted across different fungal species and substrate conditions, and researchers still debate basic questions about what these spikes actually represent biologically — hypotheses range from simple integrity-checking signals analogous to, as Adamatzky described it, “wolves howling just to tell each other about their presence,” to genuine information transfer resembling a primitive language. Building a validated, standardized sensor system that translates raw fungal electrical activity into a defensible carbon sequestration estimate, rigorous enough to satisfy carbon market auditors, would require years of dedicated interdisciplinary research that, as far as current literature shows, hasn’t yet begun.
Why It Matters
If this connection holds up under actual research, the appeal is a fundamentally different verification paradigm: rather than periodically sampling soil or inferring carbon storage from satellite imagery and computational models, a network of low-cost, continuously operating bioelectric sensors could provide a real-time, direct biological readout of the actual process responsible for sequestering carbon. Given that the entire voluntary carbon market’s current credibility problem stems from the gap between what’s claimed and what can be verified cheaply and reliably, a genuinely direct biological signal, if it proves real and quantifiable, could be a meaningfully more trustworthy foundation for a market that badly needs one.
The Human Dimension
There’s something quietly poetic about the possibility that the answer to a market’s credibility crisis might be sitting, entirely unnoticed, in the electrical hum of an organism that has no brain, no nervous system, and no interest whatsoever in carbon markets — simply doing what mycorrhizal fungi have done for hundreds of millions of years, moving carbon and nutrients through a network too small and too quiet for humans to have thought to listen to, until two unrelated fields of research happened to describe the same underground world from opposite directions.
Sources:
1. “Below-ground Fungal Biodiversity Can be Monitored Using Self-Supervised Learning Satellite Features,” arXiv, 2026 — https://arxiv.org/pdf/2604.09818
2. “Global density and biomass of arbuscular mycorrhizal fungal networks,” Science, 2026 — https://www.science.org/doi/10.1126/science.adu4373
3. “Enhanced stabilisation of soil carbon via arbuscular mycorrhizal fungi and biochar,” Scientific Reports, 2025 — https://www.nature.com/articles/s41598-025-23219-0
4. Dehshibi & Adamatzky, “Electrical activity of fungi: Spikes detection and complexity analysis,” arXiv/Biosystems, 2020 — https://arxiv.org/pdf/2008.10276
5. Adamatzky, “Language of fungi derived from their electrical spiking activity,” Royal Society Open Science, 2022 — https://royalsocietypublishing.org/doi/abs/10.1098/rsos.211926
6. “Directional Electrical Spiking, Bursting, and Information Propagation in Oyster Mycelium Recorded with a Star-Shaped Electrode Array,” arXiv, January 2026 — https://arxiv.org/pdf/2601.08099
7. “Trend analysis: Soil carbon MRV & incentives,” Sustainability Atlas, January 2026 — https://sustainableatlas.org/post/trend-analysis-soil-carbon-mrv-incentives-where-the-value-pools-are-and-who-captures-them-644
8. “Crediting agricultural soil carbon sequestration,” Science, review — https://www.science.org/doi/abs/10.1126/science.abl7991
Idea originated at artificialideas.org. Article researched and written by Claude Sonnet 4.6. Published at artificialideas.org.
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