The Seaweed Solution and the ‘Silverbuckshot’ Approach

Kelp Drying King Island

A recent Catalyst show on ABC TV featured Tim Flannery of the Climate Council put forward a ‘silver bullet’ solution to climate change. Cultivating fast growing seaweeds would draw down the CO2 in the atmosphere thus mitigating greenhouse enhanced global warming. Flannery wrote about this in his Atmosphere of Hope (Text, Melbourne, 2015) when he said:

“Seaweed is hugely productive, outstripping the fastest growing land-based crops many times over in its rate of growth and CO2 absorption. Globally, the potential scale of seaweed farming is 600 times greater than any other method of cultivating algae… One study asserted that seaweed farming could produce 12 gigatonnes per year of biomethane, while storing 19 gigatonnes of CO2 per year directly from biogas production, plus up to 34 gigatonnes per year from carbon capture of the biomethane combustion exhaust gas. All of this would come from seaweed ‘forests’ covering and area equal to 9 per cent of the world’s ocean surface.” (p.41)

In the TV show Flannery emphasized the carbon captured by the seaweed dropping to the deep ocean floor where it would be permanently stored. He also outlined many of the problems facing such a massive project such as the problem of nutrients required for seaweed growth in the open ocean.

Personally although the optimism associated with Flannery is a breath of fresh air I have a problem with concentrating on a single solution – the ‘silver bullet’.  Washington and Cook in their Climate Change Denial (Earthscan, London, 2011) talked of the ‘silver buckshot approach’. They noted:

“Climate change also impacts on almost everything we do – whether it’s water use, food production, forestry, house building or industry. If we accept the reality of the problem how do we go about solving it? Hume refers to what have been called ‘wicked’ problems, a term derived from cultural theory. Wicked problems have no simple solution…Rather than just one ‘silver bullet’ to solve the problem he suggests silver buckshot. No single solution is sufficient (Pittock 2009). The silver buckshot are the multiple solutions one applies to the problem. We agree that solving climate change – and the underlying environmental crisis it is a symptom of – will require several different approaches, a number of ‘silver buckshot’. (p.119)

The ‘silver buckshot’ solutions are manifold. I prefer options that can be implemented immediately in our currently hostile political environment like planting trees or installing rooftop solar. Many other possible ‘silver buckshot’ have been suggested by organisations such as Beyond Zero Emissions. Carbon sinks including soil carbon, fast growing trees, mangroves, biochar, CO2 absorbing cement (recently proposed by BZE) are among the suggestions. Some of these were mentioned on the Catalyst program.

There is a need to work simultaneously on a wide range of solutions some of which will be far more successful than others. On the other hand applying a ‘silver bullet’ like Flannery’s seaweed solution, whilst ignoring the CO2 we keep putting into the atmosphere with our coal-fired generators, cars and forestry operations is a recipe for disaster.