Using seaweed to reduce livestock emissions and mitigate climate change

By Nigel Little, General Manager New Zealand, CH4 Global

CH4 Global is leveraging proven science and technology to convert AsparagopsisAmarta, a native New Zealand seaweed, into a feed supplement that reduces methane produced by cows, sheep and other ruminant animals by up to 90%.

Due to naturally occurring bacteria in their gut, cattle and sheep burp methane. In New Zealand, the agriculture sector accounted for 48.2% of the country’s total greenhouse gas (GHG) emissions in 2019 with 75% of those emissions coming from methane. The dairy sector alone accounted for 22.4% of New Zealand’s total emissions, making it the biggest single contributor to GHG emissions – even larger than the transport sector at 19.7%.

According to the Intergovernmental Panel on Climate Change, methane is 86 times more potent than CO2 at warming the atmosphere over a 20 year period. Over time this multiplier drops, as methane breaks down into CO2 and water, but in the short-term methane has an oversized impact on global warming and its reduction has an outsized benefit in reducing CO2 equivalent emissions.

Most of the decarbonisation platforms developed so far (wind, solar, carbon capture, electric cars etc) will not achieve significant impact on GHG levels by 2030 because they cannot be scaled up fast enough. It is important that investment in those platforms is maintained, but their impacts will be 20–50 years from now and we need to act faster than that. Asparagopsis fills this gap, delivering significant GHG reductions within 10–20 years.

Ruminants in some parts of the world have been eating seaweed as part of their diet for centuries. Anecdotal evidence suggests these animals thrive (increased body weight, better health), and scientific trials published over the past 10 years have shown that supplementing less than 1% of their regular feed (100g) with Asparagopsis results in up to a 90% reduction of methane emissions. The most recent studies, using high quality Asparagopsis, have demonstrated that doses as low as 25–50g per day cause even higher reductions in methane.

"Asparagopsis fills the delivery gap of the current platforms and delivers significant GHG reductions within 10–20 years."

Nigel Little, CH4 Global

Many other seaweeds have been studied, but the best results are produced by Asparagopsis. There are two known species, one of which (Asparagopsis Armata), is native to New Zealand. While there are over 9 million hectares of seaweeds grown globally, there is little seaweed farmed in New Zealand and Asparagopsis isn’t farmed at scale anywhere in the world.

In March 2021, CH4 Global signed the world’s first license agreement for the sale and distribution of Asparagopsis with the IP holding company Future Feed Pty Ltd. The licenses cover sales and distribution in the New Zealand and Australian markets.

CH4 Global is collaborating with the globally recognised aquaculture science organisations at NIWA, University of Otago and SARDI (South Australia), to develop systems to commercially farm Asparagopsis at scale. As part of this work, they are looking at the co-culturing benefits of Asparagopsis in absorbing nutrient waste from adjacent mussel and salmon farms, thereby improving the ecosystem of these coastal environments. CH4 Global aims to become the world’s first scale supplier of Asparagopsis – using a native New Zealand seaweed and leveraging the ideal growing conditions of our unique coastline.

CH4 Global’s immediate ambition is to reduce methane emissions from the New Zealand dairy industry by 15% by 2030 (consistent with the target set by the Climate Change Commission) solely through the supply of Asparagopsis. To achieve this target, CH4 Global estimates that it will need access to nearly 10% of all currently consented coastal water space in New Zealand. Some of this will be achieved through variations to existing consents but new resource consents will be needed. MinterEllisonRuddWatts is working with CH4 Global on a strategy to achieve this ambition.

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