• Ineffective in polar winters (no sunlight) and of limited use in summers (ice already highly reflective).
• Sudden termination can cause “termination shock” with rapid global warming.
• Potential to disrupt global weather cycles, harming food and water security.
• No global governance on costs or liability. Estimated cost: $55M/year per country (if 30 nations share).

• Technically near-impossible in remote seas like Amundsen (Antarctica).
• Extremely high costs — >$1 billion/km.
• Threatens marine circulation, fish migration, and nutrient cycles.
• Installation in harsh polar seas only possible for few months a year; requires custom-built ships.
• Risk of toxic materials leaching into ocean.

• Requires 360M tonnes of beads annually — equal to world’s plastic production.
• Major logistical and emissions challenges.
• Beads dissolve quickly, reducing effectiveness.
• Some studies show beads absorb sunlight, causing net warming.
• Costly: $500B/year for Arctic deployment; requires 100M pumps, huge energy draw.

• Flawed logic: subglacial water is constantly replenished by frictional/geothermal heating.
• Highly emissions-intensive and energy-consuming.
• Requires continuous monitoring, maintenance, and heavy infrastructure.
• Long-term sustainability questioned.

• No control over which phytoplankton species dominate, creating food chain imbalances. 
• Could harm marine biodiversity and alter global nutrient cycles.
• Needs deployment at massive, impractical scale.
• Risk of side-effects outweighs uncertain benefits.

1. Spreading finely ground basalt rock extensively on farmlands

2. Increasing the alkalinity of oceans by adding lime

3. Capturing carbon dioxide released by various industries and pumping it into abandoned subterranean mines in the form of carbonated waters

How many of the above activities are often considered and discussed for carbon capture and sequestration?

Options: (a) Only one (b) Only two (c) All three* (d) None