black-carbon-albedo-utac

GenesisAeon Package 105 — black carbon / light-absorbing-particle albedo feedback on glaciers. A new lens on the P99–P104 series: atmospheric deposition physics, not water balance, geophysics, or governance. Deliberately has no UTAC/CREP/AFET bridge — see DISCLAIMER.md.

The core idea

Soot and other light-absorbing particles deposited on snow/ice reduce albedo, increase absorbed solar radiation, and directly accelerate melt — a mechanism independent of, and additional to, greenhouse-gas warming. It's also a positive feedback: as darkened ice melts, the black carbon within it concentrates at the surface exactly where melt is already happening, further darkening it.

A deliberate, honest contrast to this ecosystem's aerosol-masking-utac: there, aerosols mask warming globally (a cooling effect, from reduced shipping-fuel sulfate). Here, aerosols deposited on the cryosphere accelerate melt locally (a warming effect, from black carbon). Same broad class of atmospheric particles, opposite climate role depending on where they end up.

What's real here

• Kang, Zhang, Qian & Wang (2020, Earth-Science Reviews) — the foundational synthesis review of the mechanism: BC concentrations in glacier ablation-zone aged snow/ice are commonly 1–3 orders of magnitude higher than in accumulation-zone fresh snow, as the darkening/melt/re-concentration cycle self-reinforces.
• Li et al. (2017, Science of the Total Environment) — a real, measured case: light-absorbing impurities enhanced summer melt on the Xiao Dongkemadi Glacier, central Tibetan Plateau, by ~15% (2014–2015 field seasons).
• Yang, Kang, Chen et al. (2025, Communications Earth & Environment) — a real, decade-long (2007–2016), plateau-wide study separating BC's direct effect (albedo → melt, +7.5%) from its indirect effect (BC-suppressed precipitation → +6.1% additional mass loss), against a total observed solid-water-storage decline of 33.7% — explicitly not the same number as BC's own combined contribution (13.6 percentage points, about 40% of the total decline). See bc_attributable_fraction_of_total_decline().

Quickstart

pip install black-carbon-albedo-utac

from black_carbon_albedo_utac import (
    is_positive_feedback,
    ablation_zone_enrichment_range,
    XIAO_DONGKEMADI_2017,
    TIBETAN_PLATEAU_2025,
    bc_total_effect_pct,
    bc_attributable_fraction_of_total_decline,
)

print(is_positive_feedback())              # True
print(ablation_zone_enrichment_range())    # (1, 3)
print(XIAO_DONGKEMADI_2017.melt_enhancement_pct)  # 15.0
print(TIBETAN_PLATEAU_2025.total_storage_decline_pct)  # 33.7
print(bc_total_effect_pct())               # 13.6 -- NOT the 33.7% total
print(bc_attributable_fraction_of_total_decline())  # ~0.40

Development

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

Citation

See CITATION.cff and .zenodo.json.