Ed Doddridge

Extreme lows in sea ice induce many changes in the physical, ecological, and societal systems of Antarctica and the Southern Ocean.

A study explores the consequences of years with low sea ice in Antarctica, including declining krill populations, warming seas, increased ice-shelf calving, and reduced access for researchers. In PNAS Nexus: academic.oup.com/pnasnexus/ar...

A line graph showing Antarctic sea ice extent anomalies for each year since 1979. The red line, which shows 2025, has just nosedived and is near the grey line for 2024.

😳
So much for the hope that 2025 might be a little less extreme.
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The impacts of extreme lows in Antarctic summer sea ice are confronting. Read all about it in our new paper just out in @pnasnexus.org

Around 250 million years ago, Earth was near-lifeless and locked in a hothouse state. Now scientists know why The answer confirms scientists’ suspicion that when our planet’s climate crosses certain ‘tipping points’, truly catastrophic ecological collapse can follow.

The speed of change that led to previous mass excitations is terrifyingly slow compared to modern change 😳
"In the case of the Permian–Triassic mass extinction, plants were unable to respond on as rapid a time scale as 1,000 to 10,000 years. This resulted in a large extinction event."

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Antarctic summer sea ice is at record lows. Here’s how it will harm the planet – and us New research explores the wide-ranging consequences of record low summer sea ice in Antarctica. From more ocean warming to extra icebergs, it’s bad news we must hear.

More info in @theconversation.com here: theconversation.com/antarctic-su...

A schematic showing many parts of the Antarctic climate system and ecosystems. Losing summer sea ice impacts pretty much all them.

The environment and ecosystems around Antarctica are a complex tapestry of interconnected systems. We've tried our best to think about all the ways that losing summer sea ice will impact our climate, ecosystems, and society. The answers we found were confronting.

The RSV Nuyina (and icebreaker) resupplying an Antarctic base using the sea ice as a platform.

Even humans use the sea ice as a platform. This photo shows the Australian icebreaker, the RSV Nuyina, parked in the ice for a resupply mission. Less summertime sea ice will make it increasingly difficult to resupply Antarctic bases like this. 📸 Jared McGhie (AAD)

Adelie penguins part way through their annual moult on a piece of sea ice.

Lots of the wildlife around Antarctica depends on sea ice. These Adelie penguins are sheltering on a piece of sea ice while they moult and replace all their feathers. Low sea ice will make it harder to find shelter and expose them to predators.

More icebergs means the ice shelves are losing mass faster, but even more importantly, our climate models don't include this affect, so we're probably underestimating how fast the sea level will rise in the future 🌊

A wave crashing into an Antarctic ice shelf. These waves damage the ice shelf causing more icebergs to break off.

Sea ice also protects the Antarctic margins from wave damage. We found twice as many icebergs break off in summers with low sea ice. 📸: Pete Harmsen (AAD)

A map of the temperature anomaly during a summer with extreme sea ice loss. The colour bar maxes out at 1.5°C.

Sea ice reflects sunlight back into space. Taking it away causes the ocean to warm. Taking away lots of it, causes the ocean to warm a LOT. (Figure from Supplementary Information)

Impacts of Antarctic summer sea-ice extremes Abstract. Antarctic sea ice plays many crucial roles in the physical environments and ecosystems of Antarctica and the Southern Ocean. In this study, we sy

Q: What happens when we lose Antarctic sea ice in the summer?
A: Bad things. A short 🧵
New research out today: academic.oup.com/pnasnexus/ar...

What's Antarctic sea ice ever done for us? Quite a lot! It cools the ocean, protects ice shelves, supports an irreplaceable ecosystem. Oh, and helps the ocean absorb $180 billion of carbon per year. Hopefully we can figure this out whilst there still is some summer sea ice...
doi.org/10.1093/pnas...

Could we live with a nuclear-armed Iran? Reluctantly, yes Both Israel and the US claim a nuclear-armed Iran would pose an existential threat. It wouldn’t. Here’s why.

"The claim an Iranian nuclear bomb would pose an existential threat to Israel or the United States and justifies unilateral, preventive military attacks makes no sense."

A screenshot from the Nature Anthropocene briefing showing a picture of a shark above a quote from David Shiffman. Helpfully there is a clarification in parentheses at the end of the quote saying that it is not a picture of David Shiffman.

Love the caption clarification in this week’s Nature Anthropocene briefing.
I definitely thought it was a picture of @whysharksmatter.bsky.social 🤪

IMAS / AAPP sea-ice researcher @edoddridge.bsky.social has been awarded the prestigious Dr Peter Smith Medal by The Royal Society of Tasmania, in recognition of his outstanding research on sea-ice changes around Antarctica.
✨Read more: tinyurl.com/5n93seke
📸 Credit Bernard Pryor OAM. @utas.edu.au

Royal Society of Tasmania medal for sea-ice researcher - AAPP AAPP researcher wins prestigious award

🌊 AAPP physical oceanographer @edoddridge.bsky.social @utas.edu.au has received a prestigious Royal Society of Tasmania medal for his outstanding research on sea-ice changes around #Antarctica.

🏅 aappartnership.org.au/royal-societ...

Looks like we’re heading for another very low sea ice winter around Antarctica
🌊 🧊 😔

Antarctica has its own ‘shield’ against warm water – but this could now be under threat The Antarctic Slope Current shields Antarctica from warm waters. But new research shows meltwater is speeding up the current, which could make it more unstable.

A little-known ocean current surrounds Antarctica & shields it from warm water further north. Once a steadfast guardian of the icy continent, the Antarctic Slope Current is being transformed by the ice it protects. And it's putting the continent’s last line of defence at risk tinyurl.com/y36mwfje

The course includes contributions from so many amazing researchers at UTAS and covers a huge range of topics including the science and philosophy of climate change.

Saturdays - ABC listen Exploring what's happening in your community, garden and lifestyle.

Have you heard about @utas.edu.au's new climate course?

I had a great chat with Mel Bush on Australian Broadcasting Corporation (ABC) Radio Hobart on Saturday about the course. You can check it out here (interview starts at 2:44:24)

A faster current could be more unstable, with eddies transporting warm water towards Antarctica faster, melting the ice even more, and accelerating sea level rise.

We found that the current will speed up by ~50% in the coming decades. This could be a problem because
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New research shows that the melting of the very ice it protects will substantially change this current.
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Antarctica has its own ‘shield’ against warm water – but this could now be under threat The Antarctic Slope Current shields Antarctica from warm waters. But new research shows meltwater is speeding up the current, which could make it more unstable.

There’s a current that flows along the edge of Antarctica. It helps keep the warm water away from the ice, slowing down sea level.
What will happen to it as the world warms? 🌡️ 🌊 🧊
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RSV Nuyina returning to Hobart after nearly seven weeks at sea.

Welcome home!

If you live on this planet, then this course is for you!

I learnt so much while helping create the course 🤯

A close up photo of small brown mushroom things growing in green moss and other stuff (don’t @ me - I’m not a biologist!).

Found some stunning autumn fungi over Easter.

“But the consequences of losing so much sea ice are hardly limited to the poles. One of the clearest global ramifications is a reduction in the amount of solar radiation reflected from Earth back into space.”