Big stakes but the science can't be rushed

01:43, Jan 31 2009

Methanobrievibacter ruminantium is a microbe in big trouble. It has been fingered by scientists as responsible for producing methane, a particularly damaging greenhouse gas, in the guts of ruminant animals - cattle, sheep, deer and the like.

Thus M. ruminantium, and its ilk, was to blame for belching about 24.1 million tonnes of CO2 equivalents into New Zealand's atmosphere in 2006, the latest year figures are available. That's 31% of this country's total greenhouse gas emissions - the biggest single category in our emissions profile and a fraction bigger than transport and energy put together.

The humble microbe's chances of an unmolested future are therefore slim.

Fortunately for M. ruminantium, scientists think they are 10 years away from inhibiting its methane-producing activities. Unfortunately for farmers, the longer it takes, the more it's going to cost them.

According to Sunday Star-Times estimates, when farming enters the emissions trading scheme in January 2013 farmers are looking at a collective liability for belched methane emissions of about $36 million each year until 2018, assuming a carbon price of $15 a tonne. At $50 a tonne, the potential liability is about $120m.

After 2018, the potential liability increases so that by 2030 the annual costs from belched methane alone are in the order of $360m-$1.2 billion.


The costs for nitrous oxide emissions and energy use are extra.

This, of course, assumes nothing is done to reduce farms' emissions profile over that time - hence the importance of finding a way to inhibit the activities of M. ruminantium.

So how much is being spent on research into ruminant methane mitigation?

The government is contributing $2.5m a year to the Pastoral Greenhouse Gas Research Consortium (PGGRC) - that's 0.34% of its research budget for 2008/09. Industry contributes the same amount.

Is that enough? PGGRC manager Mark Aspin said about 25 people were currently working on methane-related research in New Zealand.

"I think the nature of science is if you had dream resources and plenty of capability you could bring a lot more skills and capability to bear," he told the Star-Times.

"I suppose the short answer is no, there are not enough people, but in the sense of what we're doing it does make us tightly focused and we're being very painstaking about how we approach the whole issue, so it's not all bad."

In Australia the government has announced federal funding of $A46.2m ($56m) over four years to pay for climate change research. Expressions of interest for project funding closed on Friday.

Ian Johnsson, general manager of Livestock Production Innovation at Meat & Livestock Australia, said further funding would come from industry and state governments, and "within that, reducing emissions from livestock is the highest priority for funding".

Asked if he thought enough New Zealand government resource was devoted to methane research, science minister Pete Hodgson gave the following reply: "In my view the research is still at its early stages. There are many promising leads. It is also my personal view that the research is now at a stage where further investment is likely to be productive. It is most likely that further funding will come through the government's Fast Forward: New Zealand initiative which is being established now."

This probably means yes.

It's not enough for Frank Brenmuhl, chairman of Federated Farmers's dairy section. While acknowledging there is a limit to the amount of money that can be usefully spent on methane research - there are only so many scientists in the field - he is still frustrated that livestock farmers have few options to reduce their emissions.

"I did the numbers," he said. "If I have a 350-cow farm, my options are to buy another 40ha and plant it in forestry. Or I could drop my cow numbers to 225 and plant 25% of my farm in forestry. How long until we have no dairy industry?"

As a result, the work of Aspin's team assumes extra significance.

"We still believe we can do it," said Aspin. "But we don't underestimate the challenge we've got. It's a highly interactive ecology that's occurring there. Removing the methanogens or inhibiting them so they don't create methane is one side of it. If we manage to do that we've also got to do something about the hydrogen which is a natural product of the fermentation and degrading of the plant material."

Methanogens like M. ruminantium, you see, turn hydrogen into methane in the animal rumen, allowing further breakdown of plant material.

It is one of numerous different microbes, bacteria, protozoa and fungi that combine to digest animal forage, a combination that varies from cows to sheep, from pasture to pasture and even within different individuals of the same breed on the same pasture.

There have been some efforts to look at whether changes to the forage could cut methane emissions, but this appears to be a less promising field.

Aspin said scientists had been working on that for a year or two "but it's very difficult to find the constituents of a forage that lead to high and low methane. We're just in the process of completing some science that will help us to better identify that."

Even if it can be done, any benefits may not accrue to all farmers, he said.

"Because we've got animals that extensively graze as opposed to getting hard feed or grains and meals, that challenges us. Except for the dairy industry, where you see them twice a day so there's every chance you could feed them a diet as such, sheep and beef industries are grazing the hills so there are some challenges in that area."

The New Zealand dairy industry also has a competitive advantage in its pasture grazing which could be weakened by using other feeds.

Ultimately, there could be an extra payoff from the methane research, because methane production causes an estimated loss to ruminant animals of 2-15% of gross energy intake. It's possible, therefore, that methane research could lead to more animals able to graze on a given amount of land, for example, but Aspin was careful to avoid over-enthusiasm on that score.

"The nature of the science is quite focused on interfering and inhibiting the methanogen and finding solutions to that. When we've finally done that, that's when we'll start to discover what the run-on effects of that is in the rumen."

Sunday Star Times