Geoengineering in Polar Regions: A Critical Examination

Geoengineering, a topic of heated debate, is explored in a recent study led by Martin Siegert from the University of Exeter. The study, published in Frontiers in Science on September 9, critically evaluates five proposed geoengineering methods for polar regions, highlighting potential environmental and logistical challenges.

Proposed Geoengineering Methods

• Stratospheric Aerosol Injection (SAI):
  • Involves releasing aerosols like sulfur dioxide to reflect sunlight and cool the Earth's surface.
  • Challenges include ineffectiveness in polar winters and potential for "termination shocks" if stopped abruptly.
  • Estimated cost is $55 million annually per country for 30 countries.
• Sea Curtains/Sea Walls:
  • Proposes using buoyant structures to block warm ocean water from ice sheets.
  • Technical challenges include deep-sea installation and potential marine life disruption.
  • Cost exceeds $1 billion per kilometer.
• Sea Ice Management:
  • Involves scattering glass microbeads to increase ice reflectivity.
  • Concerns about ecotoxicity and potential warming effects of the microbeads.
  • Requires 360 million tonnes of beads annually, equaling global plastic production.
• Basal Water Removal:
  • Aims to slow ice movement by removing water from beneath glaciers.
  • Identified as emissions-intensive and requiring constant monitoring.
• Ocean Fertilisation:
  • Involves adding nutrients to promote phytoplankton growth, drawing CO2 from the atmosphere.
  • Uncertainty in species dominance and potential disruption of local ecosystems.

Critique of Geoengineering Approaches

The study underscores that these geoengineering strategies pose significant environmental risks and are fraught with logistical and financial challenges. The potential consequences include negative effects on marine ecosystems, high implementation costs, and limited effectiveness.

Alternative Approaches to Climate Change

• Decarbonisation:
  • Considered the most promising approach to address climate change directly by reducing greenhouse gas emissions.
  • Challenges include reliance on fossil fuels, political resistance, and supply chain issues for renewable energy infrastructure.
• Protected Areas:
  • While useful, they can displace communities and strain resources, potentially reducing ecosystem resilience.

The study concludes that sustainable climate-resilient development, emphasizing decarbonisation and better maintenance of ecosystems, is crucial for mitigating climate change effectively.