In early February 2024, global sea ice cover dropped to 15.76 million sq km, breaking the previous record low of 15.93 million sq km set in early 2023.

• Data Source: Analysis by the BBC using records from the U.S. National Snow and Ice Data Center (NSIDC).

What is Sea Ice?

• Sea ice is floating ice found in polar regions.
• It expands in winter and melts in summer, but some portion remains throughout the year.
• It is different from icebergs, glaciers, ice sheets, and ice shelves, which originate on land.
• Why is Sea Ice Important?
  • It helps cool the planet by trapping heat in the ocean and preventing it from warming the air above.
  • A decline in sea ice cover can lead to higher global temperatures and severe environmental consequences.
  • Ecosystem and biodiversity: Sea ice offers habitat for marine species and supports survival of organisms such as algae. 
  • Economic activities: sea ice affects distribution and abundance of fish populations, as it provides shelter for fish larvae and offers protection from predators (such as seals and polar bears) and harsh environments. 
    • It ultimately affects commercial fishing. 
  • Resource extraction: The retreat of sea ice has opened the way for extracting oil and gas from inaccessible areas. 

Trends in the Arctic and Antarctic Sea Ice

Arctic Sea Ice

• The Arctic ice cover is at its lowest recorded extent for this time of year.
• Since the late 1970s, an average of 77,800 sq km of Arctic ice has been lost annually.
• Between 1981-2010, Arctic ice shrank by 12.2% per decade (September minimum levels, as per NASA).
• In recent years, warmer ocean temperatures and delayed freezing have worsened the decline.

Antarctic Sea Ice

• The Antarctic initially showed a slight increase in sea ice cover until 2015.
• However, between 2014-2017, the Antarctic lost 2 million sq km of ice—four times the size of Spain.
• The 2023 Antarctic sea ice extent was 2 million sq km below normal levels, marking a historic low.
• Even in 2024, Antarctic sea ice was 1.55 million sq km below the 1981-2010 average maximum extent.

Reasons for the Decline

• Rising Air and Ocean Temperatures
  • Warmer air and ocean temperatures have delayed freezing and increased melting.
  • In the Arctic, Hudson Bay experienced late freezing due to unusually warm waters.
  • In the Antarctic, warmer air has melted the edges of ice shelves, accelerating ice loss.
• Stronger Winds and Storms
  • Antarctic ice is thinner and more mobile due to its oceanic surroundings, making it vulnerable to ice-breaking winds.
  • Storms in the Arctic Barents and Bering Seas have further broken apart ice.
• Increased Freshwater from Melting Ice
  • Melting ice introduces freshwater into the ocean, disrupting salinity balance and reducing ice formation.

Consequences of Sea Ice Loss

• Increased Global Warming
  • Less ice means more ocean water absorbs solar heat, leading to higher temperatures.
  • Polar regions are warming faster than the rest of the world due to this effect.
• Disruption of Ocean Circulation
  • The inflow of freshwater from melting ice slows down ocean currents, impacting global climate patterns.
  • This can destabilize ice shelves, disrupt the marine food chain, and alter weather systems.