James Corbett, of the University of Delaware, is an authority on ship emissions.
He calculates a worldwide death toll of about 64,000 a year, of which 27,000 are in Europe.
For decades, the IMO has rebuffed calls to clean up ship pollution.
As a result, while it has long since been illegal to belch black, sulphur-laden smoke from power-station chimneys or lorry exhausts, shipping has kept its licence to pollute. IMO rules allow ships to burn fuel containing up to 4.5 per cent sulphur.
Ships are as big a contributor to global warming as aircraft – but have had much less attention from environmentalists.
Each is a quarter of a mile long and can carry up to 14,000 full-size containers on their regular routes from China to Europe.
And, even then, it will depend on a final ‘feasibility review’ in 2018.
In the meantime, according to Corbett’s figures, nearly one million more people will die.
Thanks to the IMO’s rules, the largest ships can each emit as much as 5,000 tons of sulphur in a year – the same as 50million typical cars, each emitting an average of 100 grams of sulphur a year.
With an estimated 800million cars driving around the planet, that means 16 super-ships can emit as much sulphur as the world fleet of cars.