Jun 2, 2024 05:28 PM
(This post was last modified: Jun 2, 2024 05:28 PM by C C.)
The return of the ozone crisis: Why Earth’s atmospheric hole poses a huge threat (again)
https://www.sciencefocus.com/nature/ozon...nvironment
EXCERPTS: In 1987, two years after the Antarctic study was published, world leaders signed an international treaty at a summit in Montreal to phase out those ozone-depleting chemicals. It was an agreement known as the Montreal Protocol and is still considered to be the most successful environmental treaty in history.
Now, four decades on, research has shown that human activity risks putting that global achievement in jeopardy. While the ozone layer hasn’t fully healed yet, it is now on the right path.
[...] The latest setback has been revealed by scientists who have been keeping a close eye on the hole in the ozone layer that still appears every year over Antarctica.
[...] The reason for this extended period of potentially deadly ozone loss is simple: climate change. Catastrophic global warming-fuelled wildfires in Australia, between 2019 and 2020, released clouds of particles into the atmosphere that drove more of the ozone-eating reactions that have historically done so much damage.
Somewhat ironically, there are some proposed climate-cooling experiments – so-called geoengineering techniques – that propose ‘making clouds’ by releasing sulphate particles into the upper atmosphere. This would also deplete ozone, so, as Robinson put it: “It’s a bad idea.” (MORE - missing details)
PAPER: https://onlinelibrary.wiley.com/doi/full.../gcb.17283
Tonga’s volcanic eruption could cause unusual weather for the rest of the decade, new study shows
https://theconversation.com/tongas-volca...ows-231074
EXCERPTS: Hunga Tonga-Hunga Ha’apai (Hunga Tonga for short) erupted on January 15 2022 in the Pacific Kingdom of Tonga. It created a tsunami which triggered warnings across the entire Pacific basin, and sent sound waves around the globe multiple times.
A new study published in the Journal of Climate explores the climate impacts of this eruption.
Our findings show the volcano can explain last year’s extraordinarily large ozone hole, as well as the much wetter than expected summer of 2024. The eruption could have lingering effects on our winter weather for years to come.
[...] Because it was an underwater volcano, Hunga Tonga produced little smoke, but a lot of water vapour: 100–150 million tonnes, or the equivalent of 60,000 Olympic swimming pools. The enormous heat of the eruption transformed huge amounts of sea water into steam, which then shot high into the atmosphere with the force of the eruption.
All that water ended up in the stratosphere: a layer of the atmosphere between about 15 and 40 kilometres above the surface, which produces neither clouds nor rain because it is too dry.
Water vapour in the stratosphere has two main effects. One, it helps in the chemical reactions which destroy the ozone layer, and two, it is a very potent greenhouse gas.
There is no precedent in our observations of volcanic eruptions to know what all that water would do to our climate, and for how long. This is because the only way to measure water vapour in the entire stratosphere is via satellites. These only exist since 1979, and there hasn’t been an eruption similar to Hunga Tonga in that time... (MORE - missing details)
https://www.sciencefocus.com/nature/ozon...nvironment
EXCERPTS: In 1987, two years after the Antarctic study was published, world leaders signed an international treaty at a summit in Montreal to phase out those ozone-depleting chemicals. It was an agreement known as the Montreal Protocol and is still considered to be the most successful environmental treaty in history.
Now, four decades on, research has shown that human activity risks putting that global achievement in jeopardy. While the ozone layer hasn’t fully healed yet, it is now on the right path.
[...] The latest setback has been revealed by scientists who have been keeping a close eye on the hole in the ozone layer that still appears every year over Antarctica.
[...] The reason for this extended period of potentially deadly ozone loss is simple: climate change. Catastrophic global warming-fuelled wildfires in Australia, between 2019 and 2020, released clouds of particles into the atmosphere that drove more of the ozone-eating reactions that have historically done so much damage.
Somewhat ironically, there are some proposed climate-cooling experiments – so-called geoengineering techniques – that propose ‘making clouds’ by releasing sulphate particles into the upper atmosphere. This would also deplete ozone, so, as Robinson put it: “It’s a bad idea.” (MORE - missing details)
PAPER: https://onlinelibrary.wiley.com/doi/full.../gcb.17283
Tonga’s volcanic eruption could cause unusual weather for the rest of the decade, new study shows
https://theconversation.com/tongas-volca...ows-231074
EXCERPTS: Hunga Tonga-Hunga Ha’apai (Hunga Tonga for short) erupted on January 15 2022 in the Pacific Kingdom of Tonga. It created a tsunami which triggered warnings across the entire Pacific basin, and sent sound waves around the globe multiple times.
A new study published in the Journal of Climate explores the climate impacts of this eruption.
Our findings show the volcano can explain last year’s extraordinarily large ozone hole, as well as the much wetter than expected summer of 2024. The eruption could have lingering effects on our winter weather for years to come.
[...] Because it was an underwater volcano, Hunga Tonga produced little smoke, but a lot of water vapour: 100–150 million tonnes, or the equivalent of 60,000 Olympic swimming pools. The enormous heat of the eruption transformed huge amounts of sea water into steam, which then shot high into the atmosphere with the force of the eruption.
All that water ended up in the stratosphere: a layer of the atmosphere between about 15 and 40 kilometres above the surface, which produces neither clouds nor rain because it is too dry.
Water vapour in the stratosphere has two main effects. One, it helps in the chemical reactions which destroy the ozone layer, and two, it is a very potent greenhouse gas.
There is no precedent in our observations of volcanic eruptions to know what all that water would do to our climate, and for how long. This is because the only way to measure water vapour in the entire stratosphere is via satellites. These only exist since 1979, and there hasn’t been an eruption similar to Hunga Tonga in that time... (MORE - missing details)