Balancing GHG reduction with increasing export value

NZAGRC's summary of options for GHG reduction.
Under half of the required reduction of global greenhouse gas (GHG) emissions from agriculture can be achieved with current options, a new international study suggests. New Zealand scientists are in the forefront of looking at other mitigation technologies and also how to balance reducing emissions while achieving the Government’s goal of doubling the value of New Zealand’s food exports by 2020.
A recent visit to the New Zealand Agricultural Greenhouse Gas Research Centre (NZAGRC) in Palmerston North led to a fascinating meeting on the complex topic with NZAGRC director Dr Harry Clark and Pastoral Greenhouse Gas Research Consortium (PGgRC) manager Mark Aspin.
Clark and Aspin pointed to a newly released international paper – Reducing emissions from agriculture to meet the 2°C targetpublished in Global Change Biology  – which estimates that GHG emissions from agriculture need to be reduced by one gigatonne [one billion tonnes] per year by 2030 to help achieve the goals set at December’s global climate change conference in Paris. That conference confirmed a long-term goal of limiting warming from climate change to well below 2°C.
The report’s panel of 33 international authors, including one New Zealander Dr Andy Reisinger who is also deputy-director of the NZAGRC, argue that focusing emissions reductions only on sectors such as energy and transport (where emissions will need to be reduced to close to zero well before the end of the century) would be insufficient to meet the temperature goal set by the new climate agreement. They say that agriculture must also play its part, proposing that the global institutions concerned with agriculture and food security set a sectoral emissions target for agriculture linked to the 2°C warming limit. Yet their detailed analysis revealed a major gap between existing mitigation options for the agriculture sector and the reductions needed: currently and readily available interventions would only deliver between 21 to 40 percent of the mitigation required.
Dr Harry Clark, NZAGRC
Dr Harry Clark, NZAGRC director: But for the 100 countries that have indicated in their national climate change targets that they would like to reduce emissions from agriculture, few have a clear plan for how to achieve this or how much they can achieve, he says. “Increasing the adoption of best practices for efficient and productive farm systems is a key element, but these alone are not enough.”
 “It will take much more coordinated efforts between national and global institutions concerned with agriculture and food security to make the progress that is needed,” he says. “New technologies are needed, hence where we come in.”

The NZAGRC – a partnership between New Zealand’s leading research providers and the PGgRC – is part of the Global Research Alliance (GRA), set up by New Zealand in 2009 and spearheaded by this country, which brings scientists and climate experts together to find ways to grow more food without increasing greenhouse gas emissions. Members include countries in South America, North America, Europe, China and Japan.

The Government-funded Centre is celebrating its recent receipt of an additional spend of $20 million over the next four years in Budget 2016, adding to the $45.8 million over 10 years initially put up by Government in 2009 in the Primary Growth Partnership. The new funding will be used to progress international GRA research through proof-of-concept to pilot studies and commercialisation and support international initiatives that address mitigation of emissions from livestock.

NZAGRC is working with the Food and Agriculture Organisation (FAO) in a United Nations sponsored project to identify regionally tailored ways of reducing GHG emissions from key livestock emissions from key livestock systems through increasing productivity and efficiency. Current focus areas are the southern cone of South America, East and West Africa and South Asia. An extension of this approach is planned to South-East Asia.

Clark, who is also co-chair of the GRA’s Livestock Research Group, says that the international study supports the approach that New Zealand has adopted for reducing agricultural GHG emissions. Improvements in production efficiency are a crucial component of reducing agricultural greenhouse gas emissions but they are not enough on their own, given the increasing global population and associated demand for food. So the NZAGRC and the PGgRc have focused on the development of new technologies that can make a large contribution to reducing overall emissions from agriculture.

“New Zealand, in a partnership between government, science and industry, is at the forefront of developing such new technologies. If successfully developed and implemented, these technologies will have global as well as local impact and would make the type of contribution the authors point out is needed for the world to achieve the target it set in Paris,” he says.

Finding ways to mitigate agricultural emissions

There are three options to reduce emissions, according to Clark: buy carbon units on the international market, which potentially moves the problem to another country; constrain production “which nobody wants”; or to mitigate emissions, which is the path New Zealand is going down. Another big challenge, says Clark and Aspin, is how to reduce emissions from a sector “when it is a massive part of your economy and of the emissions profile and you’re trying to increase that sector’s size in terms of value.”

While finding ways to eliminate emissions of carbon dioxide (CO2) is a global priority, this is primarily in the areas of waste, industrial process and transport that affect the general population, including farming families. New Zealand is in the unique position in the world of having 49 percent of its GHG emissions coming from agriculture. The majority of these are from methane (CH4), with its relatively short 12 year life in the atmosphere (compared to 1,000 years for CO2) but which traps 84 times more heat than carbon dioxide over the first two decades it is released into the air, followed by nitrous oxide (N2O). All are subjects of research workstreams for NZAGRC/PGgRC.

The PGgRC has been working on the issue for the past 14 years, since its establishment in 2002 by a number of interested parties, including AgResearch, Beef + Lamb NZ and DEEResearch, along with DairyNZ amongst others. The focus of the Consortium, together with NZAGRC, are six research streams – feed and nutrition, animal genetics and breeding, rumen modification, manure and fertiliser management, increasing soil carbon content, animal health – and an integrated farm systems programme (see right).

Mark Aspin, PGgRC.
Mark Aspin, PGgRC.

New Zealand primary sector’s main contribution to the CO2 reduction effort, through NZAGRC/PGgRC work, is in exploring ways to store it through expanding and maintaining forestry plantations. Work is also going into soil carbon sinks but, as a relatively new agricultural country, it has been discovered that New Zealand’s soils are already carbon rich and may not have much potential to store more of it, says Aspin. Work is also underway with industry groups on ways to reduce nitrous oxide and on nitrate leaching.

For methane, the aim for emissions is to stabilise and reduce rather than eliminate them, explains Clark, who says bringing methane down to zero would not be desirable for an animal, as it is part of the necessary natural biological process. Methane emissions per unit of product, such as per kg of meat, have already been going down in this country because of production efficiencies gained by New Zealand’s sheep, beef and dairy farmers using best practice, but these are already factored in to any forecast, so new technology is needed. The Centre has four current methane-focused projects: low methane animals; a new methane vaccine; methane inhibitors; and low methane feeds.

Genetic traits have been found for low methane producing animals, but these need to be combined in animals which also have all the desirable traits a meat producer might want, and researchers believe they will have “a relatively small impact over a long time,” says Aspin. He adds other work has found the opportunity to make a big impact with feeds is also small with no methane reducing advantages found from pasture crops such as ryegrasses, though some brassicas have been found to produce less methane.

David Pacheco, one of the AgResearch scientists, in the analysing room at the New Zealand Ruminant Methane Measurement Centre.
David Pacheco, one of the team of NZAGRC/AgResearch scientists, in the analysing room at the New Zealand Ruminant Methane Measurement Centre.

Most promising prospects

The most promising prospects for methane mitigation are narrowing in on the methane vaccine and the methane inhibitors. While there is a Swiss inhibitor already available on the market, it has limited effectiveness in New Zealand pasture-fed conditions. Although technically challenging, several suitable inhibitor compounds have been found to work here and seemingly have little effect on the animals’ general wellbeing. Similarly, the technical challenge for the vaccine is how to make it work across multiple species. Efforts are being made to take it one step further.

Animal trials for both are ongoing at the New Zealand Ruminant Measurement Centre in Palmerston North by NZAGRC’s Dr Peter Janssen’s team of scientists. Over 5,000 sheep and just under 400 cattle have been measured since the Centre was opened in April 2011.

Great effort is made to ensure the animals – 24 sheep and four cattle are in the current programme  –are healthy and happy so they keep on eating and ruminating – and, most importantly, emitting. While sheep have been the focus of the trials to date, as they are smaller and the gut bacteria are similar for all ruminants, work is now moving towards cattle. The animals are trained to enter into specially designed clear-sided crates – respiration chambers – that allow them to stand or lie-down, eat and to see their fellow flock members, over a couple of days.

“This gives us the opportunity to check everything that emits out of the animals,” says Janssen. The team monitors what and how much the animal has eaten and samples beforehand the air from the room that is piped into the crate. Another air sample is taken from the back of the chamber every five seconds to be sent through pipes to the analysing technology in an adjoining room, which produces a reading every four minutes for each animal for all gases.

Results have been promising. Unless there is some proof of concept breakthrough earlier, however, these are still some seven to 10 years away from commercialisation, Aspin believes, as work will be required with the commercialising company on manufacturing residue studies and so on.

But, if the results are as promising as the early trials, the final products could be – quite literally – world-changing.



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