Cop26 climate change summit: Changes to the world's oceans should worry us all – Scotsman comment

33 days to Cop26: For obvious reasons, the focus of discussions about global warming is usually on its effects on land.

However, rising temperatures are having a major impact on the world’s oceans.

The recent Intergovernmental Panel on Climate Change report said average sea levels have been rising, not steadily, but at an increasing rate – with the figure for 2006 to 2018 nearly three times that recorded between 1901 to 1971.

Levels of carbon dioxide, which results in greater acidity that threatens shellfish in particular, have been going up, while the amount of oxygen has been falling.

An earlier special IPCC oceans report said the seas had taken up more than 90 per cent of the climate system’s excess heat. “Since 1993, the rate of ocean warming has more than doubled... Marine heatwaves have very likely doubled in frequency since 1982 and are increasing in intensity...,” it said.

So if the recent heatwaves in Australia, Europe and America have been causing alarm, we should realise similar events are happening in the marine world, with devastating consequences for species such as coral.

Oceans cover 71 per cent of the Earth’s surface and have a major impact on the climate – Scotland’s relatively balmy conditions at such a high latitude being an example of what a warm current can do. Unfortunately for us, one climate change-related effect is that the main Atlantic current is weakening with an abrupt collapse this century not expected but also not ruled out.

The world's oceans have absorbed more than 90 per cent of the excess heat in the climate system (Picture: Brian Bielmann/AFP via Getty Images)

What is known about the world beneath the waves confirms how radically we have changed planet Earth. And what we don’t know is unlikely to bring good news.

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