New Delhi: Sea ice levels around Antarctica are at least four times more likely to reach a record low in 2023 due to climate change, new research has revealed.
In July 2023, Antarctic sea ice extent during winter fell to its lowest level since satellite records began in late 1978, about 2.5 million square kilometers below normal.
Researchers led by the British Antarctic Survey (BAS) are investigating the possibility of such a significant reduction in sea ice and the role of climate change in making this event more likely to occur.
Using climate datasets and models, the team found that reaching historic lows in Antarctic oceans would happen only once in more than 2,000 years, or would be "extremely unlikely" without climate change, making the event four times more likely. It will be done. It became more. Global climate model data from the Coupled Model Intercompariso Project Phase 6, or CMIP6, was used for the analysis.“This is the first time this large set of climate models has been used to explore how much sea ice loss was actually likely to occur in 2023. We only have 45 years of satellite measurements of sea ice that allow us to estimate the extent of sea ice. This makes it extremely difficult to evaluate changes in the range. "This is where climate models come into their own," said Rachel Diamond, BAS, lead author of the study published in the journal Geophysical Research Letters.
“According to the models, the record-breaking minimum sea ice extent without climate change would be similar to a 2000-year event.This tells us that the situation was very extreme — anything less than one in 100 is considered exceptionally unlikely, Diamond said.
By 2015, sea ice had experienced a sharp decline after decades of steady growth, making the sudden decline even more surprising, the researchers said.
He explained that satellite records of Antarctic sea ice began in late 1978 and between then and 2015, Antarctic sea ice extent increased slightly and steadily. In 2017, Antarctic sea ice reached a record low, and sea ice remained relatively low for several years thereafter. He said, there is a limit.Researchers also looked at how likely sea ice, which has fallen to record-low levels, is to recover.
The authors found that after such a massive loss of sea ice, not all of the sea ice around Antarctica recovered – even after 20 years. This adds model evidence to existing observational evidence that sea ice reduction over the past few years may indicate permanent regime change in the Southern Ocean and its ecosystems.
Study co-author Lewis Syme, BAS, said, "Antarctic sea ice reduction over 20 years will have profound impacts on local and global climate and unique Southern Ocean ecosystems, including whales and penguins."
In July 2023, Antarctic sea ice extent during winter fell to its lowest level since satellite records began in late 1978, about 2.5 million square kilometers below normal.
Researchers led by the British Antarctic Survey (BAS) are investigating the possibility of such a significant reduction in sea ice and the role of climate change in making this event more likely to occur.
Using climate datasets and models, the team found that reaching historic lows in Antarctic oceans would happen only once in more than 2,000 years, or would be "extremely unlikely" without climate change, making the event four times more likely. It will be done. It became more. Global climate model data from the Coupled Model Intercompariso Project Phase 6, or CMIP6, was used for the analysis.“This is the first time this large set of climate models has been used to explore how much sea ice loss was actually likely to occur in 2023. We only have 45 years of satellite measurements of sea ice that allow us to estimate the extent of sea ice. This makes it extremely difficult to evaluate changes in the range. "This is where climate models come into their own," said Rachel Diamond, BAS, lead author of the study published in the journal Geophysical Research Letters.
“According to the models, the record-breaking minimum sea ice extent without climate change would be similar to a 2000-year event.This tells us that the situation was very extreme — anything less than one in 100 is considered exceptionally unlikely, Diamond said.
By 2015, sea ice had experienced a sharp decline after decades of steady growth, making the sudden decline even more surprising, the researchers said.
He explained that satellite records of Antarctic sea ice began in late 1978 and between then and 2015, Antarctic sea ice extent increased slightly and steadily. In 2017, Antarctic sea ice reached a record low, and sea ice remained relatively low for several years thereafter. He said, there is a limit.Researchers also looked at how likely sea ice, which has fallen to record-low levels, is to recover.
The authors found that after such a massive loss of sea ice, not all of the sea ice around Antarctica recovered – even after 20 years. This adds model evidence to existing observational evidence that sea ice reduction over the past few years may indicate permanent regime change in the Southern Ocean and its ecosystems.
Study co-author Lewis Syme, BAS, said, "Antarctic sea ice reduction over 20 years will have profound impacts on local and global climate and unique Southern Ocean ecosystems, including whales and penguins."
