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The Third Way

Could large-scale seaweed farming be key to combating climate change? Could large-scale seaweed farming be key to combating climate change? Badins
09 Dec
Combating climate change requires humanity to consider various available options – could so-called ‘third way’ technologies potentially make the difference?

As the world starts to wrap up proceeding at the UN COP21 climate change conference in Paris, we – hopefully – draw ever nearer to a final agreement on keeping anthropogenic post-industrial temperature rise below the infamous 2°C threshold. And yet, thanks to years of truly determined feet-dragging, few experts expect such an agreement to be, by itself, remotely ambitious enough to prevent climate change occurring on a significant scale.

‘A global agreement is absolutely essential,’ says Tim Flannery, renowned scientist, explorer, conservationist, and Chief Councillor of the Climate Council, an independent non-profit organisation that provides expert advice to the Australian public on climate change. ‘A decade ago, if we’d acted earlier, it might have been sufficient. It’s no longer sufficient, we’re at the tail end – I hope – of a decade of worst-case scenario emissions growth. There’s enough gas in the air now to warm the temperature by 1.5°C. So, we need the “third way” now, to get us below that 2°C threshold.’

Third way technologies either enhance existing self-regulatory mechanisms, or mimic them

Flannery’s latest book, Atmosphere of Hope: Solutions to the Climate Crisis, presents a clear and concise explanation of our current climate change-driven trajectories, as well as offering a variety of strategies and technologies that could potentially be utilised to curb the impact of greenhouse emissions in the atmosphere. After addressing, first, emission-reduction efforts – such as those being negotiated at COP21 – and second, large and unpredictable geo-engineering endeavours, he coins the term ‘third way technologies’. These, he explains, are proposals based upon the planet’s natural processes which could potentially help limit the impact of climate change by drawing carbon dioxide back out of the atmosphere.

‘What we need to do is strengthen Earth’s system of self-regulation,’ explains Flannery. ‘Third way technologies either enhance existing self-regulatory mechanisms, or mimic them. If any of the technologies that I’ve talked about in the book fail to do that, we should consider them as geo-engineering.’

He divides the various proposals into two camps; the biological and the chemical options. ‘The energy source of biological pathways is the sun, the capture mechanism is plants, or living green matter of some kind, and they’re the most well established of the approaches,’ he explains. ‘But they’re also – at least the land-based ones – quite limited in scale, in relation to the problem we’re trying to solve. If you go offshore, into the water, you’re getting much more scale, but the unknowns grow as fast as the opportunities.’

Some key biological technologies include:

  • Trees – Reafforestation, or forest restoration, already takes place and is relatively cheap. However, Flannery describes the necessary scale of reafforestation as ‘staggering’ – with the example of an area the size of Australia required in order to draw down 50 years worth of carbon dioxide.
  • Biochar – Converting plant matter into ‘biochar’, a mineralised form of carbon, which can be easily stored underground, or mixed in with soil. However, it is a technology still in its infancy.
  • Wood chemistry – Returning to wood products for the manufacture of biofuels and plastics, as opposed to current petrochemical-intensive methods, could result in significantly reduced carbon dioxide production.
  • Seaweed – Fast-growing and highly CO2-absorbant, seaweed could produce enough biomethane to cover our entire energy needs, whilst simultaneously removing carbon dioxide from the atmosphere. It would, however, require as much as nine per cent of the entire ocean surface to be covered in seaweed in order to achieve this.

biocharCould biochar become an effective way of storing excess carbon? (Image: Full Circle Biochar)

‘The chemical technologies,’ Flannery says, ‘are characterised by needing some human energy source to run them. At the moment we have a very brown energy system on the planet – we burn fossil fuels to create energy – so it’s questionable to what extent we can use brown energy to draw CO2 out of the atmosphere.’ Nevertheless, in the event of a large-scale transition to low-carbon energy production, he remains confident that these ‘chemical’ technologies could have a major role to play.

Some key chemical technologies include:

  • Carbon-negative concretes – Using concrete which draws in carbon dioxide over time in new infrastructure projects. However, the technology hasn’t yet been tested over a long-enough time period to prove a reliable and risk-free alternative to regular concrete.
  • Silicate rocks – Mining and grinding up these rocks, which form at mid-ocean ridges, would stimulate the absorption of carbon dioxide as part of the process of decay.
  • Atmospheric CO2 plastics/carbon fibre – Replacing current manufacturing processes with ones which draw carbon dioxide directly out of the atmosphere, they are already considerably cheaper than the normal cost of production of, for example, carbon fibre.

Flannery’s previous books include Here on Earth as well as The Weather Makers – which Richard Branson credits as his inspiration for setting up the $25million Virgin Earth Challenge, an innovation prize to reward solutions for curbing atmospheric carbon dioxide. As a panelist for the challenge, Flannery claims that reviewing the thousands of submitted applications, ‘fundamentally altered [my] perception about how we might respond to the climate crisis’.

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