By Michael McCarthy, environment correspondent

The depletion of the Earth’s oxygen through burning fossil fuels might be a greater threat than increased carbon dioxide causing global warming, yet it is largely unheeded, a leading physicist said last night.

About sixteen billion tonnes of oxygen are being used up every year, and this might bring catastrophe, especially to parts of the ocean, which might be ‘asphyxiated’ long before the supply of the oxygen has gone, Professor Freeman Dyson said. “ It is possible that the depletion of oxygen in the ocean presents an even more serious longterm threat to the global ecology than the build-up of carbon dioxide in the atmosphere, ” he said.

“Reducing oxygen by 50 percent will cause more drastic damage to more species than increasing carbon dioxide by 50 percent. A doubling of CO2 would be for you majority of species a tolerable insult; a reduction of oxygen in the ocean to zero would be a total catastrophe.’

Professor Dyson, professor of natural sciences at the institute of advanced study at Princeton, said he was surprised that the general public all over the world was not clamouring to know how fast we were using up the oxygen.

Pointing out that eight tonnes of oxygen are used up for every three tonnes of coal, oil or gas burned, Professor Dyson called on the international scientific community to begin a programme of accurately measuring the depletion rate of oxygen. He said that the rate was at present thought to be 13 parts per million per year, and although accurate measurement was not easy, it should be possible with modern instruments.

Professor Dyson said that the biggest effects of oxygen depletion were likely to be found in the oceans because there was a much smaller amount than in the atmosphere and effects of depletion were consequently greater. ‘Catastrophe may come to parts of the ocean long before the oxygen reservoir is exhausted. The Pacific Ocean is already seriously depleted. It contains 50 percent of the Planet’s water but only 40 percent of the dissolved oxygen.’

So long as we are not measuring the rate of depletion year by year, we have no basis for guessing how soon the asphyxiation of large parts of the Pacific Ocean might begin. For this reason a programme of measurement of the oceanic oxygen fluxes is urgently necessary.’

НЕДОСТАТОК КИСЛОРОДА - СЕРЬЗНАЯ ЭКОЛОГИЧЕСКАЯ

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Oxygen Depletion a ‘Serious Threat to Global Ecology’

by Michael McCarthy

Изложено мнение проф. Дайсона из Принстонского института перспективных исследований о необходимости непрерывного контроля за содержанием кислорода (СК) в атмосфере Земли и особенно в океанах, где

СК существенно меньше. чем в атмосфере, Вызывает тревогу состояние Тихого океана, в водах которого СК уменьшилось до 40% от нормы. При отсутствии программы контроля невозможно предсказать скорость убывания СК и предупредить умирание жизни в океане.

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