Recent studies have cast doubt on the effectiveness and safety of geoengineering methods aimed at protecting polar regions. A team led by Professor Martin Siegert from the University of Exeter evaluated five prominent geoengineering techniques and found them lacking in responsibility, feasibility, and environmental safety. The findings show risks and costs, urging a rethink of such interventions in favour of sustainable climate solutions.
Stratospheric Aerosol Injection (SAI)
SAI involves releasing aerosols into the upper atmosphere to reflect sunlight and cool the Earth. However, polar winters lack sunlight, making this approach ineffective for half the year. Polar ice already reflects much sunlight, so additional aerosols add little benefit. Sudden cessation of SAI could cause rapid temperature spikes, known as termination shocks. Continuous operation is essential but costly and legally complex. Moreover, SAI risks disrupting global weather patterns, affecting food and national security.
Sea Curtains and Sea Walls
These involve installing underwater barriers to block warm ocean currents from melting polar ice. Engineering such structures in deep, remote, and hostile polar seas is technically daunting and expensive. The barriers could disrupt marine ecosystems and nutrient cycles. Marine life movement may be impeded. Costs could exceed a billion dollars per kilometre. The environmental consequences and uncertain impact on sea level rise make this option questionable.
Sea Ice Management with Glass Microbeads
Sprinkling reflective glass microbeads over sea ice aims to increase reflectivity and thickness. Yet, the beads may dissolve quickly or absorb sunlight, causing net warming. The scale required is enormous—comparable to global plastic production—posing logistical and environmental challenges. Ecotoxicity risks to marine organisms, especially zooplankton, remain unclear. Economic viability is low compared to emission reduction and adaptation strategies.
Basal Water Removal
Removing subglacial water to slow glacier movement intends to reduce ice loss and sea level rise. However, this is an energy-intensive, emissions-heavy process needing constant maintenance. The technique is unproven at scale and may not meaningfully slow glacial flow. Its feasibility and environmental sustainability are highly doubtful.
Ocean Fertilisation
Adding nutrients like iron to polar oceans to stimulate phytoplankton growth aims to increase CO2 absorption. Yet, it risks altering marine food webs unpredictably. Dominant species might consume excessive nutrients, disrupting ecosystems and nutrient flow to other regions. Large-scale deployment is uncertain and potentially harmful.
Beyond Geoengineering – Sustainable Climate Solutions
The study emphasises climate-resilient development as a better path. Decarbonisation and improved conservation are key. However, protected areas sometimes alienate local communities and disrupt traditional ecological knowledge. Fossil fuel dependence remains high globally, complicating transitions to renewables. Political resistance, financial costs, and mineral supply constraints pose further challenges. Despite these, reducing greenhouse gas emissions directly tackles climate change causes and offers long-term benefits for environment and society.
Questions for UPSC:
- Critically analyse the environmental and geopolitical challenges posed by geoengineering technologies in climate change mitigation.
- Explain the concept of climate-resilient development and discuss its importance in global climate policy with suitable examples.
- What are the major barriers to global decarbonisation? How do these affect developing countries differently than industrialised nations?
- With suitable examples, underline the role of traditional ecological knowledge in conservation and its impact on local communities and biodiversity.
