Carbon capture more costly than switching to renewables, researchers find

Role of Trees and Ecosystems vs Technological Capture

• Many argue “plant trees” is a form of carbon capture, but point out trees are good at uptake and often poor at long-term storage: they burn, rot, or are logged, returning CO₂.
• Counterpoints note significant carbon can be stored in soils, humus, peat, mature forest ecosystems, and even buildings/wood products; some say mature biodiverse forests may outperform plantations.
• Proposals include biomass burial (in mines, deep pits, swamps), biochar added to soils, kelp or algae farming, and enhanced rock weathering; all face scale, cost, and logistics challenges.
• Forest loss, desertification, and fire risk under warming climate are cited as reasons trees alone cannot offset ongoing fossil emissions.

Economics, Thermodynamics, and Feasibility of CCS/DAC

• A recurring “napkin math” argument: burning carbon releases energy, and any process to recapture CO₂ must at least pay that energy back plus losses, so capture is inherently expensive.
• Direct air capture (DAC) is criticized as thermodynamically and economically punishing because it must separate a dilute gas; current costs (~$1000/ton CO₂) are seen as politically impossible at scale.
• Point-source capture (from smokestacks, gas processing, cement, etc.) is viewed as more plausible, but still costly and only justified for “hard-to-abate” sectors.
• Some engineers push back on absolute impossibility claims: CO₂ can be stored as supercritical fluid in deep saline aquifers or mineralized in basalts; these formations have held fluids geologically. Others highlight leakage risks and survivor bias.

Motives, Greenwashing, and Who Pays

• Strong skepticism that CCS is being pushed mainly to prolong fossil fuel extraction (e.g., for enhanced oil recovery), capture subsidies, and avoid structural change.
• Long list of fossil externalities is discussed: subsidies, health impacts, climate damage, military costs, pollution, and land use (e.g., corn ethanol), arguing CCS adds another revenue stream to incumbents.
• Debate over whether emitters or consumers should pay, and whether carbon taxes pegged to actual removal costs could drive cleaner alternatives without banning fossil fuels outright.

Renewables, Nuclear, and System Costs

• Broad agreement that, for power generation, renewables plus storage are already cheaper or close to cheaper than fossil with CCS; CCS for electricity is thus seen as an “opportunity cost.”
• Disputes over nuclear: some claim it is essential for reliable, low-carbon baseload; others cite system-cost studies showing nuclear must get dramatically cheaper to compete with wind/solar plus flexibility.
• Grid issues (intermittency, storage, transmission) and end uses like aviation, shipping, fertilizer, and cement are flagged as domains where some form of carbon capture or synthetic fuels may still be needed.

Beyond “Either/Or”: Study Critique and Future Role of Removal

• Several commenters criticize the paper’s framing as a forced choice between 100% WWS (renewables) and heavy CCS, calling it unrealistic and policy-weak; they argue what matters is marginal cost and best mix over time.
• Widespread view: even with rapid decarbonization, existing atmospheric CO₂ likely requires some net-negative strategies (natural or engineered) later in the century; CCS should be treated as a niche, long-term cleanup tool, not a primary climate plan.