Volcanoes can affect climate

Volcanic CO₂ vs Human Emissions

• Multiple comments stress that volcanoes emit far less CO₂ than humans.
• One cites estimates that humans emit ~100× more CO₂ annually than all volcanoes combined.
• The 1991 Mount Pinatubo eruption is mentioned: ~0.05 GT CO₂, roughly equal to ~12 hours of current human emissions.
• Explanation that subducted carbonates (e.g., limestone) are a volcanic CO₂ source.
• Some initially assume “large eruptions must dominate,” but others counter that even very large eruptions are small next to ongoing human output.

Volcano-Induced Cooling and Historical Impacts

• Mount Tambora’s 1815 eruption and the “Year Without a Summer” are cited: rapid global cooling, crop failures, and famine.
• Krakatoa and Tambora are used as examples of why deliberately triggering major eruptions is likely a bad idea.
• Comments note that volcanoes can cool for months–years via aerosols, while their CO₂ impact is comparatively minor and long-term.

Sulfur, Aerosols, and Geoengineering Proposals

• Discussion of stratospheric aerosol injection and “volcanic winter” as a template for solar geoengineering.
• Ideas include sulfur cannons (as in fiction), extra sulfur in jet fuel, marine cloud brightening, and ship emissions as de facto “sulfur sprayers.”
• Some argue stratospheric injection gives strong cooling with less acid rain than tropospheric sulfur.

Risks, Uncertainties, and Ethical Concerns

• Concerns: crop losses from reduced sunlight, acid rain, ocean acidification compounding CO₂ effects, ozone impacts, regional weather disruption.
• Debate over how well volcanic analogs generalize: some say sulfur physics is well understood; others say complex climate feedbacks make extrapolation risky.
• A key worry: sulfates are short-lived, so stopping injections after delaying decarbonization could cause rapid “catch‑up” warming.
• Counterpoint: short lifetime is seen as a safety feature—if harmful, effects decay in 1–2 years.
• Fears of “cowboy geoengineering” by states or billionaires, with no global governance.

Climate Policy, Decarbonization, and Activism

• Strong theme: geoengineering cannot substitute for drastic CO₂ reduction; at best it buys time.
• Debate over whether temporary cooling is valuable (to bridge generational and technological transitions) or just postpones inevitable crises.
• Skepticism that global economic restructuring will occur before major catastrophes in rich countries.
• Side discussion on nuclear vs renewables, China’s trajectory, and the limited effectiveness of current activism and offsets (e.g., tree planting).

Miscellaneous

• Brief curiosity about underwater volcano climate impacts (left unanswered/unclear).
• Thread includes humor framing volcanoes as “exhaust ports/pipes” and sarcastic “news at 11” reactions.