Greenland ice sheet faces irreversible melting

Context

• The massive Greenland ice sheet could be facing a point of no return, beyond which it may no longer fully regrow, permanently changing sea levels around the world, according to study.

What are the highlights of the study?

• According to the researchers, the ice sheet is seven times the area of the UK, and stores a large amount of the Earth’s frozen water.
• The effects of Greenland ice sheet melting under a range of possible temperature rises, ranging from minimal warming to worst-case scenarios.
• At current rates of melting, they said the ice sheet contributes almost one millimetre to sea level per year, accounting for around a quarter of the total increase.
• The researchers said despite seasonal periods of growth, Greenland has lost 3.5 trillion tons of ice since 2003.
• Under all future climates like the present or warmer, they found that the ice-sheet declined in size and contributed to some degree of sea-level rise.

What are the reasons?

• Global warming is considered to be the main reason behind it.
• Under scenarios in which global warming goes beyond 2 degree Celsius, there could be significant ice loss and several metres of global sea level rise to persist for tens of thousands of years.

What would be the impacts?

• In such cases, even if temperatures later return to current levels, the study showed that the Greenland ice sheet will never fully regrow once it melts beyond a critical point.
• After this point, the sea levels would permanently remain two metres higher than current levels, regardless of other contributing factors.
• Greenland would experience warmer temperatures and less snowfall.
• To avoid partially irreversible loss of the ice sheet, climate change must be reversed — not just stabilised — before we reach the critical point where the ice sheet has declined too far.