(Image: CH4 Global/Zennie/Private Media)

This is part one in a series about searching for solutions to the climate emergency. Read parts two, three, and four.

The UN’s COP27 climate summit opened with dire footage of 71 climate-induced disasters in the year to date and — just in case that didn’t hit home — a declaration from UN Secretary-General António Guterres that the world is on a “highway to climate hell”.

As global governments continue to drag their feet on climate action, in the coming days Crikey will chronicle Australians using climate science that is leagues ahead, ready for uptake, and ripe for scale.

First stop: seaweed science.

In 2020, global seaweed production from aquaculture (land and sea farms) topped 35 million tonnes. Most of this comes from South-East Asia, with China and Indonesia the two biggest players.

Australia’s contribution is close to zero, but we enter the market with new weeds, cutting-edge science, and a pot of $8.1 million of federal government funding to help shore up the budding industry.

What’s Australia’s edge?

Add 50 grams of Australia’s cow-friendly red seaweed — Asparagopsis — to a bale of hay and it eliminates methane production by 99%. Doing so also increases the cattles’ energy productivity by 10-20%. That means fewer emissions and less food required for a cow to perform its daily duties (produce milk or become meat).

The CSIRO has estimated that sneaking seaweed into the feed of 10% of global livestock producers is akin to removing 100 million cars off the roads and (courtesy of better powered livestock) could feed an additional 23 million people.

Let’s digest this.

Standard practice inside a cow’s (one, two, three, fourth) stomach is to break down material and release it as energy. But by doing so, the gut’s internal operators bind hydrogen molecules to carbon molecules, creating a perfect recipe for methane.

Propelled through burps, ruminant cattle account for about 6% of Australia’s total greenhouse gas emissions. Open the floor to all livestock and that jumps to 10%.

But a ”squash ball”-sized batch of seaweed is enough to neutralise that. Adam Main, general manager of Australia’s first commercial seaweed supplier CH4 Global, said add seaweed into the feed mix and “their system fails” (in a good way).

“That means the carbon remains, the hydrogen remains, and the cow then uses the other things in its stomach to build them into other functional energy chains,” he says.

CH4Global is one of only three seaweed growers licensed by the CSIRO as part of FutureFeed (a seaweed supply chain established in 2020) to sell and supply the salty supplement to cattle producers. It’s been operating for three years, but only started sales this year.

Seaweed farming 101

Australia’s small but fast-growing seaweed industry is both land and sea-borne. Offshore it’s a similar game to mussel farming. It requires “ropes and floats” and not much else, says Main, who calls it “a self-sufficient crop”.

“While the seaweed’s in the water, it basically uses all the free things that are available in the marine space. It sucks up sunshine, nitrogen from the environment, and carbon,” he says.

Nitrogen is a common (and toxic) byproduct of fish farming. The nitrogen, carbon and sunshine feeders in CH4 Global’s farms grow as much as 20 metres in depth before they’re harvested using a “top-cut” technique that encourages regrowth. The seaweed snips are done manually from a boat, but Main anticipates the process will be totally automated in a few years. Divers still play a part but contending with great white sharks in South Australia is an occupational health and safety issue that Main says is best avoided by keeping people out of the water.

Once harvested, the seaweed is sedated with low light and a cold snap: “You’ve got to get it cool and keep it in the dark. And the seaweed effectively goes to sleep.”

From there, it’s out of the freezer and into the dryer. No different to freeze-dried strawberries or coffee.

Scaling up seaweed production

On land, aquaculture giant Tassal is pairing seaweed in its prawn ponds to boost water filtration. The trial is part of research at the University of the Sunshine Coast’s seaweed research group (the same team that revealed red seaweed could neutralise ruminating livestock) to expand the remit of Australia’s seaweed industry. Having “a Tassal” on board for research and development is seen as a win for an industry that “still doesn’t really exist”.

“We’re hoping to find other potential applications for the same seaweed so if we end up with a whole lot of Asparagopsis farmers in the country, they’re not just reliant on it for methane,” UniSC ecologist Professor Nick Paul says.

Pitching forward, CH4 Global is looking to ramp up its land-based operations as ocean environments are set to become increasingly volatile with the impacts of climate change. Temperature rises and increasing storm and swell surges are better managed on land.

“All of a sudden there’s a real proposition for us to be able to locate more systems on land in the region,” says Main. “Keep farming going, but in a very different way.”