In a letter to the journal Nature, James Lovelock, author of the Gaia Theory, and Chris Rapley, director of the Science Museum, have proposed using vertical pipes in the ocean to help marine plantlife absorb more carbon dioxide.

The pipes, which they suggest could be 100 to 200 metres long and 10 metres in diameter, would use wave movement to pump colder, nutrient-rich water to the ocean surface to fertilise algae in the surface waters.

These plants would consume carbon dioxide through photosynthesis and could also produce chemicals that help to cool the climate through cloud formation.

In their letter to Nature, the scientists said: “Measurements of the climate system show that the Earth is fast becoming a hotter planet than anything yet experienced by humans.

“Processes that would normally regulate climate are being driven to amplify warming.

“Such feedbacks, as well as the inertia of the Earth system — and that of our response — make it doubtful that any of the well-intentioned technical or social schemes for carbon dieting will restore the status quo.

“What is needed is a fundamental cure.”

They added: “The removal of 500 gigatonnes of carbon dioxide from the air by human endeavour is beyond our current technological capability.

“If we can’t heal the planet directly, we may be able to help the planet heal itself.”

The technology is already being developed by American firm Atmocean, using pipes 200 to 300 metres long and three meters wide.

Company bosses say the pipes could sequester an additional two billion tons of carbon per year on the ocean floor and stabilise carbon dioxide levels in the atmosphere below 550 parts per million.

They believe the process will be helped by zooplankton species which consume algae and excrete pellets containing carbon dioxide that rapidly sink to the seabed.

Their research suggests that the pipes, which bring cooler water to the ocean’s surface, could also reduce the intensity of hurricanes.

Kate Martin

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