New Delhi: The sea level has risen by nearly 10 mm since January 2022 to a new record high this year, much of this acceleration is due to the melting of the ice sheets, rather than thermal expansion of water, as per WMO’s provisional State of the Global Climate 2022 report.
“The past two and a half years alone account for 10 percent of the overall rise in sea level since satellite measurements started nearly 30 years ago,” said the report.
The report mentioned that Ice sheet loss in Greenland and parts of Antarctica is gathering pace and is largely irreversible and resulting acceleration in sea level rise is a major threat to billions of people in coastal regions.
Glacier retreat in high mountain areas brings the risk of long-term water scarcity in densely populated parts of the world.
“We’ve raised the red flag for the cryosphere,” WMO Deputy Secretary-General Dr Elena Manaenkova said in summarizing the latest scientific knowledge and the physical climate change signs.
“Today’s grave impacts from cryosphere loss pale, however, in comparison to what the latest science tells us would be increasingly severe and widespread impacts at higher levels of global warming,” said the statement.
Repeated interventions and presentations at the UN climate negotiations, COP27, said that meeting the goals of the Paris Agreement to keep temperature increase to 1.5°C to 2°C above pre-industrial levels will determine the fate of the Greenland and Antarctic ice sheets and the high mountain “Water Towers” of the world and the future of the large parts of the planet.
Arctic sea-ice extent was below the long-term (1981-2010) average for most of the year. The September extent was 4.87 million km2, or 1.54 million km2 below the long-term mean extent. Antarctic sea-ice extent dropped to 1.92 million km2 on 25 February, the lowest level on record and almost 1 million km2 below the long-term average.
2022 took an exceptionally heavy toll on glaciers in the European Alps, with record-shattering melt. The mountains in the Hindu-Kush region – the so-called Third Pole – have also suffered. The Greenland ice sheet lost mass for the 26th consecutive year.
In Antarctica, the ice loss is currently largely confined to the West Antarctic ice sheet which – like the Arctic – is warming more rapidly than the global average and this is one of the factors behind accelerating sea level rise.
East Antarctica is by far the world’s biggest ice sheet, containing water which is the equivalent to around 50 meters of sea level rise. And so far, the East Antarctic ice sheet has seen very little surface melting, according to Dr Chris R Stokes, a professor in Sea Level, Ice and Climate at Durham University in the United Kingdom.
“So far that ice sheet seems to be okay. East Antarctica is the huge sleeping giant we don’t want to wake up,” said Dr Stokes. “But we have been ignoring this ice sheet for too long and it’s something we need to start looking at now. History tells us that sea level rise from ice sheets can be very, very rapid,” he said.
“We are at 1.1°C now above the pre-industrial era and we are already struggling. It’s hard to imagine what’s going to happen at 1.5°C and above,” R Stokes said.