If one ice sheet hits the ocean, sea levels could rise by 58 metres in our lifetime

It came out in September. The ABC had some coverage, but it seemed to miss some essential points.

Here is what the new science tells us and how it is different from the older science.

The older science tells us that the amount of sea ice in Antarctica is shrinking, but not as badly as in the Arctic. Sea ice expands and contracts quite quickly according to air and sea temperature. So, a gradual reduction in sea ice will mean a gradual and comparatively small rise in sea levels.

This science should be moderately alarming, but the misinformationists in the fossil fuel industry can bat away public fears by saying not much is happening here and it will not happen in your lifetime, so carry on as usual.

This is standard stuff from fossil misinformationists: climate change is not happening, but if it is happening it is part of natural geologic forces and has nothing to do with human-generated carbon, and even if it is caused by human-generated carbon we can develop technologies to capture the carbon and safely store it away.

In short, they base their facts on their desired conclusion that they can continue to make profits from the emission of carbon until ecosystems and economies collapse. When it is too late.

Coming back to Antarctica, earlier science suggested that sea-ice contraction could be reversed if temperatures came down a bit. As it happens, sea ice is an important reflector of solar rays (and heat). Without the sea ice you have dark ocean which absorbs the rays and increases the heat of the ocean. Nonetheless, it is still a probably reversible process.

Enter the new research. This is about the eastern Antarctic ice sheet. Hitherto, this has given climate scientists much less cause for concern. This is because the eastern ice sheet has built up over land. It is anchored.

Unlike sea ice it is not vulnerable to warmer water melting it.

Picture the land mass and a big thick ice sheet over it. The sea nibbles at the edge and even if the sea is a bit warmer it does not melt much ice. This is not like sea ice, where the warmer water is all around it, melting it quickly. So, hitherto scientists have taken some climate solace in the fact that so much ice is safely tied up in the eastern Antarctic ice sheet (more than 60 per cent of the world's freshwater) and so will give us more time to slow and reverse the warming of the planet.

Enter the new research. Remove the image of a lump of land mass. Rather picture that the land mass has been forced down by the weight of the ice - heavier at the middle of the land mass and lighter at the edge.

The new science tells us that much of the eastern Antarctic ice sheet is grounded below sea level. So, once the warmer sea waters get under it, the whole sheet becomes unstable and can slide into the ocean.

And even if temperatures are made to fall, the tipping point would have been reached - the warmer sea would have run under the massive ice-sheet, undermining it and making its slide into the ocean inevitable.

And once the ice sheet slides into the ocean, there is no putting it back, even if all carbon emissions ended that day. The ice sheet holds enough water to raise sea levels by 58 metres. Even if only half of it breaks off, it will be just a waiting game over just a few years for the ice to melt and for us to watch every coastal city on earth to be inundated. In our lifetime.

Once the ice sheet hits the ocean, it is the end of civilisation as we know it.

The ice cannot be put back.

The greater the potential damage the more you should do about it, even if you think the risk is small. This is why people go to a lot of effort to make their houses less exposed to bushfires and cyclones.

It may be that some billionaires might imagine they could set up doomsday retreats to avoid death, injury, and discomfort. They are dreaming.

In those circumstances money means nothing and the profit-driven selfishness that drives unnecessarily extending the use of fossil fuel will be brushed aside by the maniac selfishness of those on a desperate if doomed survival mission.

Scientists must change stop their subdued, cautious approach to reporting climate change. It is understandable because scientists do not want to cause panic or unnecessary alarm. But the approach has just given the fossil industry endless free kicks. It is time for alarm and measured panic.

Scientists should stop being scared of publishing scary material in a scary way. It is time to tell people the reality of the biggest security, economic, and existential threat to humans on earth.

As the year draws to a close, it is perhaps worth mentioning the atmospheric research at the Mauna Loa Observatory in Hawaii which samples air away from local pollution that might skew results.

Atmospheric carbon hit (I would like to hope peaked) at a record 429 parts per million in 2024 up from 417 in 2020 - in years that the world was supposed to making efforts to reduce carbon, not allow it to rise.

In 1958 it was just 318ppm. The Mauna Loa Observatory's data puts the lie to any idea that humans are not on a trajectory of self-immolation.

It is mirrored by the CSIRO's 50 years of data from the appropriately named Cape Grim, again away from local pollution.

That said, the Cape Grim data can at least let us end the year on a note of optimism. It is reporting that the amount of ozone-destroying chlorofluorocarbons is falling. World action under the 1987 Montreal Protocol has saved the planet from life-threatening runaway UV radiation due to depleting to ozone level.

If selfish, profit-obsessed people are side-lined, it could also happen with carbon. Happy New Year.