Lecture Notes: The Eruption of Mount Tambora and Geoengineering

Mount Tambora Eruption (1815)

Date: April 10, 1815
Location: Present-day Indonesia
Event: Largest eruption in recorded history
Immediate Impact:
- Sulfurous plumes and ash clouds
- Sun obscured for nearly a year
Consequences:
- "Year without a Summer" (1816)
- Global cooler temperatures
- Agricultural havoc and famines in the Northern Hemisphere
- Epidemics and bleak artistic expressions

Definition: Deliberate, large-scale interventions in Earth’s systems to mitigate climate change
Types of Geoengineering:
- Solar Radiation Management (SRM):
  - Block sunlight from reaching Earth
  - Large-scale proposals (e.g., volcanic plumes, giant sunshades)
  - Smaller-scale projects (e.g., enlarging marine clouds, white reflective surfaces)

Volcanic Eruptions as Natural Experiments:
- Examples:
  - 1991 Pinatubo Eruption
  - 1883 Krakatoa Eruption
- Effects: Temporary global cooling (~0.5°C)
Risks of Geoengineering:
- Unpredictable Climate Effects:
  - Impact on precipitation and extreme weather
- Potential Global Disasters:
  - Cross-border consequences, such as crop failures
- Incomplete Solutions:
  - Only address temperature, not greenhouse gas levels
  - Risk of "super warming" if stopped prematurely

Small-Scale Experiments:
- Example: Enhancing marine clouds to protect the Great Barrier Reef
Priority of Actions:
- Reducing emissions and removing CO2 should come first
Future of Geoengineering:
- Potential last-resort measure
- Need for preparedness against unauthorized geoengineering
Unintended Geoengineering:
- Climate change driven by fossil fuel emissions
- Urgent need to curb emissions to prevent permanent climate alterations

Geoengineering carries significant risks and uncertainties.
Priority should remain on reducing emissions and CO2 removal.
Continued research is crucial to understanding and potentially controlling geoengineering effects.