Mount Teide Volcano Context

• Canary Islands home to Mount Teide, world's largest active volcanoes
• Capable of spewing tens of millions cubic meters lava per eruption
• Contains basalt rock potentially useful for climate intervention
• Destroying volcano would cause catastrophic ecological fallout

Natural Rock Weathering Process

• Rainwater + atmospheric CO2 = weak acid attacking silicate minerals
• Silicates present in 90%+ of Earth's exposed rock
• Acid reaction converts dissolved CO2 to bicarbonate
• Bicarbonate flows to ocean where marine creatures use for shells
• Dead shells sink to seafloor, trapping CO2 for millennia
• Process impacts Earth's climate over millions of years
  • Warm/wet conditions: weathering speeds up, reduces greenhouse warming
  • Cold/dry conditions: weathering slows, builds atmospheric CO2

Enhanced Rock Weathering Strategy

• Two key factors determine weathering pace:
  • Rock type exposed to weather
  • Amount of rock exposed
• High-temperature silicates weather faster (deep mantle rocks, volcanic basalt)
• Mountain formation limits rock exposure
• Solution: harvest fast-weathering rock, crush, spread for accelerated weathering
• Leverages existing mining/processing technology
• Agricultural communities know volcanic rocks improve crop yield
• Farmlands ideal dispersal sites

Implementation Challenges

• Requires global deployment for meaningful impact
• Measurement difficulties:
  • Rock weathering runs through entire global water cycle
  • Open system with countless variables
  • Precise impact measurement nearly impossible
• Logistical challenges:
  • Massive ecological/engineering challenge to quarry, crush, transport, spread rock
  • Energy sources must be clean to maintain net carbon benefit
• Potential side effects:
  • Quarried rocks may contain dangerous heavy metals/unknown elements
  • Unpredictable impacts on Earth's natural systems at scale

Projected Impact

• Simulations show global program spreading 10 tons basalt dust per hectare of global farmland
• Could sequester 200+ gigatons CO2 over 75-year period
• Remarkable figures for cheap, practical approach