Introduction
Climate engineering, also known as geoengineering, refers to deliberate, large-scale interventions in the Earth’s climate system aimed at mitigating or reversing the effects of climate change.
There are two main categories of climate engineering:
- Solar Radiation Management (SRM)
- Carbon Dioxide Removal (CDR)
Solar Radiation Management (SRM)
SRM techniques aim to reflect a small percentage of the sun’s light and heat back into space to cool the Earth.
Some proposed SRM methods include:
- Stratospheric Aerosol Injection: Introducing reflective particles (such as sulfur dioxide) into the stratosphere to reflect sunlight away from the Earth.
- Marine Cloud Brightening: Spraying seawater into the atmosphere to increase the reflectivity (albedo) of clouds.
- Space-based Reflectors: Deploying mirrors or other reflective objects in space to reflect sunlight.
- Surface Albedo Enhancement: Increasing surface reflectivity (e.g., painting roofs white or growing reflective crops).
Carbon Dioxide Removal (CDR)
CDR methods focus on removing CO₂ from the atmosphere and storing it safely.
Some CDR techniques include:
- Afforestation and Reforestation: Planting trees to absorb CO₂ through photosynthesis.
- Bioenergy with Carbon Capture and Storage (BECCS): Growing biomass for energy, capturing emitted CO₂, and storing it underground.
- Direct Air Capture: Using chemical processes to capture CO₂ directly from the air.
- Ocean Fertilization: Adding nutrients to stimulate phytoplankton growth to absorb CO₂.
- Enhanced Weathering: Spreading CO₂-absorbing minerals over large areas.
How Climate Engineering Helps in Tackling Climate Change
- Temperature Regulation: SRM provides temporary cooling by reflecting sunlight.
- CO₂ Reduction: CDR directly lowers atmospheric greenhouse gas levels.
- Complementary Approach: Supports traditional mitigation like emission cuts and renewable energy.
- Rapid Impact: Some SRM methods can deliver immediate cooling during emergencies.
- Adaptation Support: Helps ecosystems and societies adapt by stabilizing temperatures and CO₂.
Limitations and Challenges
- Unintended Consequences: May cause unpredictable side effects on climate and biodiversity.
- Moral Hazard: Could reduce urgency for reducing emissions.
- Governance and Ethics: Global cooperation is needed; raises legal and moral questions.
- Technical Feasibility: Many methods are experimental and unproven at scale.
- Public Acceptance: Skepticism about manipulating Earth’s climate may hinder adoption.
Conclusion
A balanced approach, combining traditional mitigation and carefully governed climate engineering—based on sound science and ethics—is essential for effectively addressing climate change.