Last month, New Zealand scientists came together for an emergency summit on one of the most alarming developments yet observed on our planet.
The Southern Ocean was suddenly missing about 20 per cent of the sea ice that’d normally be covering it – equivalent to an area roughly 10 times the size of New Zealand.
This record low - observed for the second year running – has led some experts to suggest we’ve now crossed a tipping point, where this seasonally swelling and shrinking apron of ice around Antarctica won’t ever regrow to its former extent.
It’s not the only
thing telling scientists something is wrong in what remains an under-studied, yet critically important, part of our world.
A staggering 150 billion tonnes of Antarctica’s land ice is now annually entering the Southern Ocean, which itself is becoming stormier, warmer, higher and increasingly deoxygenated.
An ocean that’s long sucked up a large chunk of the carbon dioxide we’ve pumped into the atmosphere – essentially helping save us from ourselves – is growing more acidic as it struggles to keep up with our rate of climate pollution.
That affects the delicate balance of marine life, meaning “more seaweed and less kina, paua and pipis on our beaches”, as one scientist put it.
This year, we learned melting ice is also putting Antarctica’s globally important deep currents on a path to potential collapse.
Cold water near the North and South poles normally sinks to the bottom of the ocean and is carried around the world by currents but this “overturning” process is predicted to slow by 40 per cent in the next 30 years.
That would isolate the deepest, coldest layer of water at the bottom of the world’s oceans, massively reducing their cooling effect and exposing the world to the full impact of increasing greenhouse gas emissions.
For New Zealanders, the impact will be even more of the changes we are already seeing - increasingly powerful storms, higher seas and more flooding.
New Zealand climate scientists say the top priority - apart from more much-needed research in Antarctica and the Southern Ocean - is an urgent global move away from fossil fuels, especially new oil and gas drilling, to save the planet while we still can.
Read Herald science reporter Jamie Morton’s full story below
