Larvatus Prodeo

Geoengineering – that is, deliberately doing things to modify the Earth’s climate – is something that’s come up a couple of times on LP. There’s a (sort-of) new proposal doing the rounds in a very preliminary form – dumping lime into the ocean, increasing the capacity of the ocean to absorb CO2. The idea is not actually new, but a guy called Tim Kruger has received some funding from Shell to investigate it further. Interestingly, he’s conducting the investigation in an open source manner, keeping all the information gained in the public domain.

To get the lime, you need to heat limestone, which releases a molecule of CO2 in the process. However, the lime, when added to the ocean, will increase the ocean’s ability to absorb CO2 by two molecules, so the process appears to be a net win even without directly sequestering the process CO2. But they’re also looking at sequestering that too. The heat source for heating the limestone is also under investigation – Shell’s interest is in using stranded natural gas, but Kruger is also examining alternatives like solar furnaces. As you might gather, this is all very preliminary; the discussions on the project website haven’t – to my knowledge – revealed any showstoppers yet.

It’s of course impossible to predict at this stage whether this proposal is technically, environmentally, or economically feasible. You have to wonder about the consequences of dumping billions of tonnes of lime into the world’s oceans. But, like all of these proposals, I also know that the alternative of not geoengineering isn’t looking great either.