
Syllabus :GS3/Environment
Context
- A new study led by University of Exeter’s Martin Siegert critically assesses five major geoengineering methods aimed at protecting Earth’s polar regions and finds them ineffective, costly, and environmentally risky.
| What is geoengineering? – Geoengineering encompasses a wide range of ideas for deliberate large-scale attempts to modify Earth’s climate. – The two broadest classes involve removing carbon dioxide from the atmosphere and increasing the amount of sunlight reflected back into space (known as “solar radiation modification”). – Five most developed concepts For the polar regions. 1. Stratospheric Aerosol Injection (SAI) is a solar radiation modification technique that involves releasing fine particles like sulphur dioxide or titanium dioxide into the stratosphere to reflect sunlight and cool the Earth, specifically targeting polar regions. 2. Sea Curtains are large, flexible, buoyant structures anchored 700–1,000 meters deep on the seafloor and rising 150–500 meters. (a). Their goal is to block warm ocean water from reaching and melting ice shelves and grounding lines, thereby slowing the flow of ice from Greenland and Antarctica into the ocean. – Sea ice management involves using glass microbeads to increase ice reflectivity and pumping seawater to thicken ice or create snow, aiming to preserve Arctic sea ice. – Basal water removal aims to slow ice flow in Antarctic and Greenland ice sheets by extracting water from beneath ice streams to increase friction. – Ocean fertilisation proposes adding nutrients like iron to polar oceans to boost phytoplankton growth, enhancing carbon dioxide absorption and storage in the deep ocean. |
Key Findings of recent study
- Stratospheric aerosol injection (SAI) : Limited effectiveness due to polar darkness, risks of sudden temperature spikes if stopped, high ongoing costs, and potential global climate disruptions.
- Sea curtains: Huge technical and logistical challenges, high costs (over $1 billion per km), and harmful impacts on marine life and ocean circulation.
- Sea ice management: Ecotoxicity risks from microbeads, impractical scale and energy demands for pumping seawater, and questionable effectiveness coupled with very high costs.
- Basal water removal: Energy-intensive, emissions-heavy, and requires constant monitoring.
- Ocean fertilisation: Uncontrolled effects on marine ecosystems and impractical large-scale deployment.
- The study concludes that these geoengineering methods fail to meet responsible climate intervention standards and may cause severe environmental harm.
Suggestions
- The study advocates for “climate-resilient development,” emphasizing decarbonisation and better ecosystem management as more effective, though challenging, solutions.
- Despite obstacles like fossil fuel dependency, high renewable infrastructure costs, political resistance, and global equity issues, reducing greenhouse gas emissions directly addresses the root cause of climate change and offers broader environmental benefits—making it the most promising path forward.
Source :TH
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