Greenhouse gases and sea levels record in 2021, confirms international report – India Education | Latest Education News | World Education News

Records have been broken again in 2021 with the highest greenhouse gases, ocean heat and global sea levels on record, the latest State of the climate report confirms.

The report is an international, peer-reviewed, annual summary of significant global climate changes and events, says Dr. Kyle Clem, senior lecturer in climate science at Te Herenga Waka—Victoria University of Wellington.

Dr Clem is the editor of the report’s Antarctica and Southern Ocean chapter, which shows that 2021 has been another year of extremes in the region.

Huge and rapid fluctuations in sea ice cover have been observed, with new record daily cover in October and December, he says.

“Sea ice extent started well below average in January and February 2021. It then increased rapidly in March and remained above average for much of the fall and winter. winter, with near-record daily sea ice in August. Then, as rapidly as it rose, it rapidly declined in September and October, dropping to new daily highs.

These fluctuations are alarming, because the Antarctic sea ice is a crucial part of the Earth’s climate system, says Dr Clem.

On the ice sheet, Antarctica has been losing around 140 gigatonnes (billion tonnes) of ice mass per year since 2003.

“Most of this mass loss comes from West Antarctica in the South Pacific, where warm ocean water is melting protective ice shelves from below. In 2021, this trend has continued, with large mass losses and thinning of glaciers in the West Antarctic region A continent-wide net mass loss of 50 gigatonnes was observed, adding about 0.14 mm to the global sea level rise.

However, Dr Clem says the total loss of ice mass in 2021 was below the long-term trend, as there have been significant surface mass gains from heavy snow accumulations in other parts of the region. Antarctica, linked to an unusually high number of extreme weather events that caused large landfills. of snow on the mainland in October and December.

“These heavy precipitation events, which occur sporadically as mid-latitude atmospheric rivers are guided towards Antarctica, are likely to become more intense in a warming atmosphere that can hold more moisture.

“2021 has shown that the interplay between extreme precipitation events and melting – both governed by warming – is an important factor affecting Antarctica’s annual contribution to sea level rise.”

At other extremes, the entire Antarctic Peninsula experienced a very warm year, along with huge sea ice cover deficits along the coast, and Esperanza Station tied for its hottest year. hottest ever recorded.

Inside, the South Pole experienced its coldest winter (April to September) on record.

“This record cold over the interior was linked to a stronger than normal polar vortex (a belt of westerly winds circulating around Antarctica that traps cold air over the continent), coupled with favorable local conditions which improved cooling during the long polar night.These conditions included light surface winds and clearer skies allowing heat to escape.

Dr Clem says the record winter has not significantly affected the long-term warming trend at the South Pole and that this region continues to warm more than twice as fast as the global average.

2021 also saw the second longest-lived ozone hole on record.

“The Antarctic ozone hole, which occurs between late August and November, is still a prominent feature of the southern polar region. It remains a key driver of Southern Hemisphere weather and climate during the summer, including mid-latitude regions such as New Zealand where it influences the north-south location of summer storms.

However, the 2021 ozone hole has shown signs of “healing”, due to the decrease in the amounts of ozone-depleting substances in the atmosphere, says Dr Clem.

“The 2021 ozone hole, although long-lived, had a slow growth rate and its size and minimum ozone concentration values ​​were less severe than those observed in the early 2000s, when the ozone hole ozone was at its strongest.”

The state of the climate in 2021 is led by American scientists National Environmental Information Centers and published by the Bulletin of the American Meteorological Society. More than 530 scientists from 60 counties contribute to the publication.

Comments are closed.