Soil Moisture

DISCLAIMER — Real Science, No Framework Bridge

Why no UTAC/CREP/AFET bridge: not only because the cited literature already provides the necessary quantitative structure -- a deliberate choice. This project's highly speculative AFET/UTAC experiments must never stand in the way of climate/ecology topics being accessible and usable to people who don't work inside that construct and aren't looking for renormalization groups. Real, checkable science, without the burden of an unproven framework. See PACKAGE_REGISTRY.md's "Why no UTAC/CREP/AFET bridge in the climate/ecology series" (2026-08-31) in the GenesisAeon workspace root for the full canonical note.

Status: Real, verified science + NO UTAC/CREP/AFET bridge

What this is

• Critical soil moisture (CSM) is a real, well-established threshold in
• land-surface hydrology: below it, evapotranspiration shifts from an
• energy-limited to a water-limited regime, which suppresses evaporative
• cooling and amplifies both drought and heatwave severity through a
• positive land-atmosphere feedback loop.
• Fu et al. (2024, Nature Communications 15, 4826): global mean CSM of
• 0.19 m³/m³, ranging from 0.12 m³/m³ (arid ecosystems) to 0.26 m³/m³
• (humid ecosystems), derived from satellite and in-situ observations.
• Qiao et al. (2023, Nature Communications 14, 4908): soil-moisture–
• atmosphere (SA) coupling contributes an estimated 0.68±0.38°C to
• end-of-21st-century global land warming under a high-emission scenario,
• with regional hotspots (Europe, North America) up to 2.4°C and a
• 10-50%+ increase in extreme-heat event probability.

What this is NOT

• Not a bistable tipping element. Unlike AMOC, the Amazon, or the
• Greenland ice sheet, critical soil moisture is not a proposed
• ir

…

soil-moisture-utac

[](https://github.com/GenesisAeon) [](https://github.com/GenesisAeon/soil-moisture-utac/actions/workflows/ci.yml) [](https://www.python.org) [](LICENSE) [](https://doi.org/10.5281/zenodo.21780601)

GenesisAeon Package 90 — real critical soil moisture threshold science. Deliberately has no UTAC/CREP/AFET bridge — see DISCLAIMER.md.

For a plain-language explanation of the same topic (German, no jargon, written for general audiences), see WHITEPAPER.md.

What's real here

• Fu et al. (2024, Nature Communications): global mean critical soil
• moisture (CSM) threshold of 0.19 m³/m³, ranging from 0.12 m³/m³ (arid)
• to 0.26 m³/m³ (humid) ecosystems.
• Qiao et al. (2023, Nature Communications): soil-moisture-atmosphere
• coupling contributes an estimated 0.68±0.38°C to end-of-century global
• land warming, with regional hotspots up to 2.4°C.
• Explicitly not framed as a bistable tipping element like AMOC or
• the Amazon — see DISCLAIMER.md.

Quickstart

bash pip install soil-moisture-utac

```python from soil_moisture_utac import is_water_limited, GLOBAL_MEAN_CSM_M3_M3

print(f"Global mean critical soil moisture: {GLOBAL_MEAN_CSM_M3_M3} m3/m3") print(f"Water-limited at 0.10 m3/m3? {is_water_limited(0.10)}") ```

Development

bash pip install -e ".[dev]" pre-commit install ruff check src tests mypy src pytest

Citation

See CITATION.cff and .zenodo.json.