New Zealand lamb and beef’s greenhouse gas (GHG) emissions intensity is falling as production efficiencies make gains.
The biennial NZ Agricultural Greenhouse Gas Mitigation Conference was held in Palmerston North at the end of March. This brought together 11 speakers – climate change and livestock scientists, domestic and international policy specialists, representatives from the red meat and dairy sector and economists – to focus on what recent progress has been made.
According to the information presented to the 157 delegates over the day, New Zealand sheepmeat and, to a lesser extent, traditional beef production is doing relatively well.
Accurately measuring the carbon footprint throughout the whole of a food product life cycle, in an internationally agreed scheme, has been taxing the minds of scientists internationally. The debate has moved beyond food miles and the carbon labelling that had been proposed by British retailers to encompass other environmental impacts, explained AgResearch principal scientist Dr Stewart Ledgard. The EU is proposing the introduction of a European Product Environmental Footprint (PEF) within the next year or so, to which products such as New Zealand meat would be subjected, he added
For that reason, interest in Life Cycle Analysis (LCA) which follows a product’s life cycle from “cradle to grave”, including feed and energy inputs, is being rejuvenated.
According to Ledgard, LCA analysis has demonstrated that New Zealand lamb has a lower footprint across the whole chain, when compared to other international studies – 5-8 kgs of carbon dioxide equivalents (CO2eq) per kg liveweight versus 5-33 kgs/ CO2eq.
Studies comparing New Zealand lamb with British (Williams et al, 2008) and French product (Gac et al, 2014) [see figure right] found very favourable results for pasture-raised New Zealand lamb. The total carbon footprint for the New Zealand product was lower than both the British and French lamb raised on grass and French lamb housed for at least part of the year and fed with crops.
Further research by Ledgard in 2014 followed New Zealand lamb from birth to consumption in British homes, showing it had a total carbon footprint of 19 kg CO2eq/kg of meat. It was found the majority of this (80 percent) happened behind the farm gate, around 10 percent was accounted for at the consumption end in retailing, cooking and waste, about seven percent in transport (the majority of this was incurred in ocean shipping with smaller amounts for domestic transport in NZ and the UK), round two percent by the processor (fuel, waste water, electricity and other overheads).
The UN’s Food & Agriculture Organisation (FAO), for which Ledgard led a Technical Advisory Group of the Livestock Environmental Assessment and Performance (LEAP) partnership on developing guidelines for estimating GHG emissions from small ruminant supply chains, has done work on GHG emissions from beef that shows the product’s carbon footprint is not equal around the world. This 2013 study (see left) shows Oceania (primarily Australia and NZ) has a comparable GHG profile to North America and Western Europe, which ranges between 25-35 kgs CO2eq/kg of meat, compared to South Asia (over 150 kgs CO2eq/kg) and sub-Saharan Africa (around 119 kgs CO2eq/kg).
Further research done in Australia on grass-fed versus grain-fed beef (Wiedemann et al, 2015) found an advantage for grain-finished beef (21.6 kg CO2eq/kg of meat, compared to 25.5 kg for grass-fed). However, Ledgard highlighted, the amount of fossil fuel energy used in its production was greater than with a pasture-based system.
Putting the New Zealand red meat sector’s perspective forward, Beef + Lamb NZ (B+LNZ) chief executive Sam McIvor talked about progress already made by the sector – “possibly the most de-regulated in the world” – which has 30 million fewer sheep being raised today, compared with 30 years ago. He pointed to the sector’s productivity gains which mean the same amount of meat is being produced by half the number of animals, lambing percentages rising by 25 percent since 1990 to 125 percent today, lamb weights lifting by 93 percent and that cuts are being exported now rather than carcases.
“It’s been calculated that since 1990, GHG emissions have fallen by 19 percent on sheep and beef farms, on less land,” he said.
In his presentation, Dr Ledgard had pointed to B+LNZ data showing production efficiencies had already resulted in the amount of methane (CH4) emitted per sheep dropping by 30 percent from just over one kg CH4/kg sheep carcase weight in 1990 to just over 0.7 kg CH4/kg sheep carcase weight in 2015.
The emissions intensity – kgs CO2eq/kg of meat – had improved by 23.1 percent for sheepmeat and 19.7 percent for beef since 1990, said McIvor, about one percent a year.
“What’s more – in a time when all over the world the meat industry is being challenged on its environmental/sustainability footprint, New Zealand has a strong argument to mount around its production methods, Over 70 percent of the land farmed by sheep and beef is hill country. It’s land producing food that would otherwise be wasted,” he said.
Noting recent urban criticism of agriculture he said: “If NZ stops producing food, other less efficient countries will step in to take our place.”
He urged politicians to understand farmers, who are proud stewards of the land.
The sector is investing in the future through the Pastoral Greenhouse Gas Research Consortium (PGgRC), established 14 years ago, which is supported by eight partners, include B+LNZ, DEEResearch, Dairy NZ, Landcorp and AgResearch. In turn, the Consortium funds work at the NZAGRC, which organised the conference and is a leader in the international Global Research Alliance, looking at the development of technology to help pastoral farmers to mitigate GHG emissions.
Other speakers outlined the relatively slow but very steady progress being made into CH4 mitigation technology – especially into methane inhibitors and the methane vaccine (Dr Peter Janssen, AgResearch), nitrous oxide emissions (Dr Cecile de Klein, AgResearch) and New Zealand’s potential soil carbon sinks (Professor Louis Schipper, University of Waikato).