SYDNEY, 22 Feb 2023:
Stronger El Niño climate patterns in the future could accelerate an “irreversible” thaw of Antarctica’s ice shelves and ice sheets, Australian scientists reported yesterday.
El Niño and La Niña are climate patterns in the Pacific Ocean which respectively cause warmer and colder conditions and form the El Niño Southern Oscillation (ENSO) cycle. They can have a global impact on weather, wildfires, ecosystems and economies.
After analysing 31 climate models, research by Australian government agency Commonwealth Scientific and Industrial Research Organisation (CSIRO) concluded that an increase in the variability of ENSO leads to reduced warming near the surface, but accelerated warming of deeper ocean waters.
“Climate change is expected to increase the magnitude of ENSO, making both El Niño and La Niña stronger,” said lead author Wenju Cai in a CSIRO statement.
“This new research shows that stronger El Niño may speed up warming of deep waters in the Antarctic shelf, making ice shelves and ice sheets melt faster.”
However, the modelling in this research, published in the scientific journal Nature Climate Change, pointed out an increase in ENSO variability slows down the intensity of the westerly winds along the shelf – and as a result, the upward movement of deeper, warmer waters is reduced.
“Warming around the edges of floating sea ice is slowed during this process, slowing down the melting of sea ice near the surface,” Cai said.
Ariaan Purich, co-author from Monash University, said the effects of increased ENSO variability go beyond extreme weather risks.
“This could have broad implications for the global climate system, so continuing to understand how ENSO will respond to climate change is a critical area of climate research.”
Meanwhile, the International Energy Agency (IEA) yesterday demanded global methane emissions be slashed after a 2022 rise despite soaring energy prices making actions to reduce them “cheaper than ever.”
Methane emissions from the energy sector reached almost 135 million tonnes last year – up from 2021 and slightly below the 2019 record – despite globally high energy prices, security of supply concerns and economic uncertainty, IEA’s annual report said.
The energy sector is responsible for about 40% of all methane emissions attributed to human activity, second only to agriculture.
“Methane emissions from oil and gas alone could be reduced by 75% with existing technologies, highlighting a lack of industry action on an issue that is often very cheap to address,” IEA said.
It would take less than 3% of the revenues of oil and gas companies around the world in 2022 to make the investments necessary to achieve such a drastic cut, the document stressed.
Approximately 260 billion cubic metres of methane are lost to the atmosphere each year in oil and gas operations, and three-quarters of that amount could be retained and brought to market using known techniques and technologies, the IEA said.
“Our new Global Methane Tracker shows that some progress is being made but that emissions are still far too high and not falling fast enough – especially as methane cuts are among the cheapest options to limit near-term global warming. There is just no excuse,” said IEA executive director Fatih Birol.
One of the main greenhouse gases, methane is responsible for around 30% of the increase in global temperatures since the beginning of the Industrial Revolution, said the report.
The report also highlighted satellites as useful for detecting methane super-emitting events, of which there were more than 500 last year at oil and gas facilities and another 100 at coal mines.
The Global Methane Pledge, launched in November 2021 at the COP26 Climate Change Conference, has around 150 participants that have collectively committed to reduce methane emissions from human activities by 30% by 2030.
Contributing countries currently account for 55% of total methane emissions from human activities and about 45% of methane from fossil fuel operations.
“It will be critical for participants to formulate pragmatic strategies and measures to reduce their own emissions, and to engage with countries that have not yet joined the pledge,” the IEA said.
– EFE