• Project ‘could turn back clock’ on carbon dioxide
• Guardian conference will select top 10 climate ideas
Putting lime into the oceans could stop or even reverse the accumulation of CO2 in the atmosphere, according to proposals unveiled at a conference on climate change solutions in Manchester today.
According to its advocates, the same technique could help fix one of the most dangerous side effects of man-made CO2 emissions: rising ocean acidity.
The project, known as Cquestrate, is the brainchild of Tim Kruger, a former management consultant. “This is an idea that can not only stop the clock on carbon dioxide, it can turn it back,” he said, although he conceded that tipping large quantities of lime into the sea would currently be illegal.
The oceans are a key part of the natural carbon cycle, in which carbon dioxide is circulated between the land, seas and atmosphere. About half of the CO2 released into the air by humans each year is soaked up by the oceans. This helps slow the rate of global warming but increases ocean acidity, posing a potentially disastrous threat to marine ecosystems.
Kruger’s scheme aims to boost the ability of the oceans to absorb CO2 but to do so in a way that helps reduce rather than increase ocean acidity. This is achieved by converting limestone into lime, in a process similar to those used in the cement industry, and adding the lime to seawater.
The lime reacts with CO2 dissolved in the water, converting it into bicarbonate ions, thereby decreasing the acidity of the water and enabling the oceans to absorb more CO2 from the air, so reducing global warming.
Kruger said: “It’s essential that we reduce our emissions, but that may not be enough. We need a plan B to actually reduce the amount of CO2 in the atmosphere. We need to research such concepts now – not just the science but also the legal, ethical and governance considerations.”
Kruger’s plan was one of 20 innovative schemes proposed at the Manchester Report, a two-day search for the best ideas to tackle climate change staged by the Guardian as part of the Manchester International Festival.
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Duncan Clark, The Guardian, 6 July 2009. Full article.