Picture an island with 15,000 people on it and a sea that is climbing by about a metre over the next hundred years. Now picture the bill for keeping the water out.
Alexander Osadchiev is an oceanologist, a Doctor of Physical and Mathematical Sciences and a leading researcher at the Shirshov Institute of Oceanology of the Russian Academy of Sciences. He thinks the metre itself is the easy part. The hard part is who pays.
Two things push the sea up, and he says their contributions are almost equal. One is extra water arriving from the land-based ice of Antarctica and Greenland. The other is plain heating: the top two kilometres of the ocean warm up, and warm water takes more room, the way a heated pen stretches a little. Floating sea ice adds nothing, because Archimedes' principle makes it displace exactly as much water as it will become when it melts.
The pace is slow, and that matters most. If the sea rose a metre a year, he says, it would be a catastrophe and humanity would be forced to solve it. A metre in a hundred years is a different kind of problem. "With our technology" it can simply be built against.
Rich places already do this kind of building. Dubai piles up sand into palm-shaped islands. Japan, where land is expensive, makes new ground from fill. St Petersburg has its own defences. Put up coastal barriers, and, in his words, nothing floods. You could raise them three metres if you wished. For New York or the Maldives it is a question of money and nothing else.
Here the story turns. Poor countries, and especially those with long, low coastlines, will suffer badly. They have no money for it, and he says they never will. A small island with 15,000 residents would need someone to chip in. Otherwise it has no resources.
His own verdict is unsoftened:
If you think about it sensibly, 15,000 people want a huge amount of money so their island isn't flooded. Well, sorry, move. Well, a cruel but, unfortunately, unavoidable reality.
Если там здраво посудить, 15 тысяч человек хотят огромные деньги, чтобы их остров не затопило. Извините, переселитесь. Жестокая, но, к сожалению, неизбежная реальность.
— Alexander Osadchiev, Gleb Solomin Podcast, 33:08
He calls it a cruel but, unfortunately, unavoidable reality. He does not pretend otherwise.
Do the sums and the logic is hard to dodge. A World Bank report from 2024 puts adaptation for Tuvalu alone at roughly US$1 billion in present-value terms, for half a metre of sea rise by the period 2070–2100. That is about twenty years of the country's entire GDP. Nobody in the report's arithmetic has that sitting in a drawer.
The wealthy are not untouched. A study in Scientific Reports in 2024 found that a high-end scenario would cost the EU and UK 1.26% of GDP, €871.8 billion, with some coastal regions losing between 9.56% and 20.84%. But those are regions inside countries that can draw on a national budget.
Osadchiev also wants the argument kept in numbers. People in a debate say "more" and "less" because they have not looked at the figures, he says, and the one who sounds surer wins. Here the figure is one metre, over a century. For some coasts that is a construction schedule. For an island of 15,000 it is a date by which everyone leaves.
