Global Warming Solution
Hopes Dampened
By Toby Murcott
BBC News Science
Experiments carried out from a submarine three kilometres under the ocean have poured cold water on one of the more ambitious schemes for dealing with global warming.
The idea was to store the carbon dioxide produced by the burning of fossil fuels under the ocean, stopping it from getting into the atmosphere and adding to the greenhouse effect.
In theory this would have reduced the rate of global warming, but now a report in the journal Science suggests that putting the idea into practice may not be so simple.
Carbon dioxide in the atmosphere acts like a blanket over the Earth, trapping heat in, causing the planet to heat up.
The gas is released into the air from burning fossil fuels, so the obvious answer is to cut down on their use.
The idea of storing the carbon dioxide out of harm's way deep in the oceans is a more radical proposal.
The high pressures and low temperatures on the sea bed should force the carbon dioxide to form a type of solid known as gas hydrate, which should remain safely locked away and not reach the air.
To test this, researchers from the Monterey Bay Aquarium Research Institute in the United States took flasks of carbon dioxide down to the sea floor in a submarine, and then watched what happened.
The gas did react with the seawater to form hydrates, but these expanded rapidly and started to dissolve.
As a result the researchers concluded that it is unlikely that large amounts of carbon dioxide would remain in an undersea store for any length of time.
This is disappointing for those who hoped it might offer a long term solution for gas disposal.
However, the carbon dioxide might remain in the depths for a few decades, by which time technology might offer another solution to the problem of storing it.