A post on the Point of Order blog today reports on concerns about the contribution of methane to climate change and to the research in New Zealand and Australia to find ways of reducing methane emissions in farm animals…
A warning bell sounded for New Zealand farmers when The Economist – in an editorial last week headed “It is not all about the CO2” – argued that carbon dioxide is by far the most important driver of climate change, but methane matters too.
The final sentence of the editorial reads, ominously:
“Methane should be given priority on the COP26 climate summit this November”.
NZ may fight its corner vigorously at the Glasgow summit, but the risk is that delegates there will seize on the thesis advanced by The Economist that methane is a more powerful greenhouse gas than carbon dioxide, and decide to target it harshly.
“Reduce methane emissions and you soon reduce methane levels; reduce methane levels and you reduce global warming”, says The Economist.
With NZ’s greenhouse gas emissions comprising about 49% methane, this country could be savaged by climate change warriors, while other countries could follow the European Union in contemplating a tariff regime, or what it calls a carbon border adjustment mechanism (CBAM), in which the price of imports reflect their carbon content. Such a mechanism, if adopted broadly, could severely penalise NZ agriculture exports.
So the search has begun for solutions to the problem of agricultural methane emissions.
A small group of New Zealanders see the answer in a variety of seaweed called Asparagopsis that reduces the amount of methane cows burp into the atmosphere. Nelson’s Cawthron Institute is running a one-year research project, with $100,000 in government funding, to look at Asparagopsis’s preferred growing conditions.
The Provincial Growth Fund earlier awarded $500,000 to a company, CH4 Global, which aims to grow and process the seaweed in NZ and South Australia. Both are working with Australian teams at research organisation CSIRO and James Cook University, who discovered that the fluffy native algae could reduce the amount of methane let off by farm animals.
On the face of it, the research looks promising. Studies in both the lab and on live animals have found supplementing the diet of sheep and dairy cows with 1-3% of dried seaweed can reduce their methane emissions by 60-90%. But behind those numbers lie logistical, food safety and animal health questions.
Dr Michael Lakeman, chief science officer of CH4 Global, speaks enthusiastically about the work with the seaweed. He says if you fed each of NZ’s dairy cows a tiny amount of it each day, this seaweed would remove as much greenhouse gas emissions as by converting every vehicle on our roads to electric power.
Unlike humans, sheep and cattle can digest cellulose in plants. The first of their four stomachs – the oxygen-starved rumen – contains an army of micro-organisms that help ferment the feed, reducing it to smaller molecules that the animal can then turn into energy.
Among the microbes are methanogens, which like to hang out in oxygen-free spots.
They combine fermentation by-product hydrogen with carbon dioxide, to produce methane and water. The methane, or CH4, is released when the animal burps.
Unlike most microbes in the gut, scientists’ best guess is that methanogens are not essential to digestion, so if you could reduce their activity, you could reduce methane emissions without affecting the animal’s growth and health.
In the case of Asparagopsis, scientists have worked out that bromoform – a chemical found in many seaweeds – inhibits the methanogens, reducing methane release.
Dr Lakeman says results of their work have been promising. They show that a tiny amount of Asparagopsis in the feed of beef cattle cut methane emissions by 98%, while leaving no residues in the meat.
These cattle also gained weight 50% faster than those that didn’t have seaweed in their feed.
“Results like this encourage us that Asparagopsis can be a game-changer for NZ’s livestock industries, even as we acknowledge there are still challenges to be overcome before that potential is realised”.
The research being undertaken into the seaweed looks likely to come into sharp focus if COP26 leads to action on methane. NZ has a chance to do things differently, providing the research produces the answers envisioned by people like Dr Lakeman.
Dairy and meat that comes without a climate footprint will command a premium price.
Source: Point of Order