Solving climate change by abusing thermodynamic scaling laws

Original Article ↗ Hacker News Discussion ↗

A proposal to fight climate change by growing biomass and freezing it in massive insulated piles prompts scrutiny of both physics and practicality. Commenters question nutrient loss, methane emissions, structural and climatic constraints, and whether such a scheme could ever scale to match global CO₂ output, comparing it to alternatives like biochar, ocean fertilization, and direct air capture. The exchange broadens into whether technological fixes alone can meaningfully offset emissions, or whether political action and changes in consumption habits remain the primary levers.

Nutrient Cycling and Biomass Removal

  • Major concern: schemes that bury or freeze whole plants also lock away nitrogen, phosphorus, and other nutrients needed for ongoing agriculture.
  • Some suggest partial processing: burn wood, capture CO₂ as carbonates, and return the nutrient-rich residue; or pyrolyze biomass so most nutrients are driven off and can be recycled.
  • Others note existing agricultural practice of building humus in topsoil, but scaling this to climate impact is unclear.

Biochar and Other Biomass-Based Sequestration

  • Pyrolysis to produce charcoal/biochar is repeatedly proposed as simpler and more stable than freezing: stores mostly carbon, can enhance soils, and is ancient/low-tech.
  • Pushback: simple calculations suggest you’d need to convert “all plant matter several times a year” to offset emissions; scale is the core problem.

Freezing-Pile Proposal: Practical Concerns

  • Structural and thermal questions: can pipes withstand the weight; can a frozen core really persist through summers; what about rain infiltration?
  • Proponents argue most of the mass would remain frozen, with only a thin decomposing shell; critics worry about water percolation, loss of insulation, and long-term thaw.
  • Methane and nitrous oxide from anoxic zones in the pile could be significant, possibly negating benefits; mitigation strategies are unclear.
  • Risks like spontaneous combustion of wet biomass are raised.

Scale, Thermodynamics, and Efficiency

  • Debate over direct air capture (DAC): some call it “thermodynamically unviable” in practice; others counter that while energy- and cost-intensive, physics doesn’t forbid it and waste heat is negligible vs greenhouse forcing.
  • Photosynthesis is acknowledged as relatively inefficient compared to solar PV, limiting biomass-based approaches.
  • Several comments emphasize that any biomass or DAC solution must be judged mainly by scalability and full energy/transport cost.

Alternative Sequestration Schemes

  • Radical concept: convert captured carbon to silicon carbide and bury it in deserts as an effectively permanent sink; criticized as massively energy-intensive and more suitable as sci‑fi or a hypothetical doomsday device than as mitigation.
  • Ocean fertilization is floated as attractive given ocean area and natural deep sequestration; others call it risky for ecosystems and physically vulnerable to storms and tectonics.
  • Simpler ideas include planting fast-growing or long-lived trees, then either using harvested wood in long-lived structures or burying it under coal-forming conditions.

Renewables, Energy Growth, and Substitution

  • Strong thread arguing that rapidly expanding solar/wind plus electrification (EVs, heat pumps) is the primary lever; solar is far more efficient at capturing sunlight than crops.
  • Some highlight that solar additions now rival or exceed demand growth, suggesting fossil use will peak soon; others note fossil extraction is still rising and Jevons-type rebound effects remain.
  • Several criticize “primary energy” metrics as misleading: electrification can cut total energy demand by 2–5× for many end-uses.

Policy, Carbon Taxes, and Equity

  • Carbon taxes are widely viewed as powerful but politically difficult.
  • Concerns: regressivity (hurting poorer households using dirtier energy), backlash if people are locked into high‑carbon systems, and the need for rebates or targeted support.
  • Examples are given of per-capita rebates that partially offset regressivity; others argue strong taxes must be phased in gradually but that this is now late relative to climate timelines.
  • Some say a tax-plus-sequestration-bounty (pay per ton reliably removed) could drive both emission cuts and drawdown.

Technology vs Behavior and Politics

  • One camp: people will not voluntarily change consumption at scale; only technological fixes and price signals are realistic.
  • Another camp: social and political change is essential (e.g., limiting advertising, reshaping transport and housing, diet shifts), because climate is intertwined with broader ecological damage and consumption culture.
  • Several suggest a “yes, and” approach: many small and medium-size measures combined (renewables, efficiency, sequestration, policy, behavior) rather than a single silver bullet.