Southern Irony

Carbon sequestration, o’ the irony…

Giant icebergs are carving off the polar ice caps as globally warming accelerates. We have all heard of this and it is a very bad thing.

Some good news though; researchers have discovered that as these giant icebergs melt they release trapped iron into the iron deficient waters of the high latitudes.

This iron acts as a fertilizer for photoplankton which thrives, consumes carbon dioxide and then dies, sinking to the ocean bottom thereby trapping the carbon dioxide.

Apparently this effect contributes up to 20% of all the carbon buried in the Southern Ocean, which itself contributes about 10% of the global total.

We aren’t talking about a lot of dissolved iron here by the way. Bugger all.

Here’s the calcs…

The concentration of dissolved iron in icebergs is highly variable and between 4-600 nM (source: http://bit.ly/1TTNRHf)

The total global ice melt is around 742 cubic kilometres per year (source: http://bit.ly/1Zs7n4k) much of which isn’t from icebergs, but I’ll use this number as a worst case scenario.

Taking the median of iron concentration and working through the maths, this equates to 125,140 tonnes of iron released from all ice melt, per year, globally.

Now I’d just like to point out that the largest ocean tanker  in service has a gross tonnage of 234,006 tonnes (source: http://bit.ly/1RL0Hs6)

Get to it, fuckers!