An independent report commissioned by the Centre for Innovation and Excellence in Livestock has concluded new methods of mitigating carbon emissions from livestock production must be found in order to reach net zero targets by 2050. Hannah Noble reports.
Speaking at a press briefing for the release of the new report, Sarah Buckingham, Scotland’s Rural College (SRUC) said in order to deliver net zero targets by 2050 the UK agricultural and land use sectors must reduce carbon emissions by 64 per cent.
However she added that by employing existing mitigation strategies a reduction of just 19 per cent could be achieved by 2035.
Ms Buckingham explained the aim of the report was to join up existing streams of research across all UK livestock sectors to provide a summary of what is currently known about the impact of carbon and address gaps in knowledge and technology.
She said the current mitigation strategies available included improved animal management such as improved animal breeding, health and diet, the mitigation of feed ingredients, the refinement of production and utilisation of feeds, the use of new or novel feeds such as home-grown proteins, and improved manure management in terms of better storage and utilisation.
She also said soil and land management was a key mitigation strategy which included improved nutrient and fertiliser use efficiency, the inclusion of legumes and nitrification inhibitors and general land management which promoted good soil health.
She said: “Existing mitigation technology could potentially decrease emissions by 7.1 mega tonnes CO2 equivalent by 2035, however this is only 19 per cent of our net zero target, this leaves 82 per cent to be delivered between 2035 and 2050.”
Therefore she said current mitigation and research would not meet the requirements for net zero carbon emission targets.
“To address this we need to increase the uptake of existing mitigation technologies, determine and quantify the cumulative and interactive effects of applying multiple mitigation strategies," added Ms Buckingham.
“We also need to find new and novel mitigation options that can be deployed as well as considering carbon removal strategies.”
Also speaking at the briefing, Bob Rees, SRUC, said agriculture contributed about 10 per cent of the UK’s annual greenhouse gas emissions, which was mainly in the form of methane from ruminal livestock and nitrous oxide emissions from the use of nitrogen fertilisers.
However he said it was also important to recognise agriculture was a significant contributor to the UK economy, bringing in £12 billion per year and livestock based foods made an important contribution to human nutrition converting poor quality forages into high quality human food.
He added: “In order to be sustainable the livestock sector has to strongly reduce its greenhouse gas emissions and the good news is there is a lot that can be done with the current technologies and understanding.”
He said this could be achieved by further employing best management practises to improve efficiencies, using novel and alternative feeds, addressing fertiliser usage and using smart technologies.
He said mitigation alone was not enough for the UK to reach its target, and in order to do so the remaining emissions needed to be offset by greenhouse gas removals from the atmosphere. He explained it was possible this could be achieved by burning biomass in power stations, through carbon sequestration, the use of biochar and direct air capture but it was uncertain how effective the technologies were and further research and development was needed.
Mr Rees said: “If the quantity of greenhouse gas removal and mitigation potential is insufficient we may be forced to look at reduced consumption of livestock products which needs to be linked to reduced production.”
Dr Elizabeth Magowan, of the Agri-Food and Biosciences Institute, co-ordinated the report, and said it was a ‘call to action’ for the industry.
She said: “While the industry is making steps in the right direction, the ambition to achieve the UK’s target is huge and known technologies and practices can only get us part of the way.
“The report concludes that a combination of greater investment, improved carbon accounting and education resulting in adoption, are required for the UK livestock industry to achieve its net zero carbon goal within the next 30 years.”
When looking at the carbon footprints of the different livestock sectors Graham McAuliffe, of Rothamsted Research, said of the dairy systems, grazing herds with on average 270 days access to pasture per year were associated with the highest carbon footprint. This was related to the lower average yield of the cattle compared with the systems with extended housed periods, average higher milk yields and greater efficiency.
This was mirrored by poultry with the cage or colony system, given its more intensive production and higher yields of eggs per hen, found to have the lowest carbon footprint. The same could be said for chicken meat production where standard rearing practises had a lower carbon footprint than free range or organic systems. Across all the poultry systems, the biggest impact of carbon use was through their use of feed.
In pigs there was a negligible difference between the carbon footprints of indoor and outdoor pigs however since 2002 the pig industry had worked to cut its carbon from above 3.5 kg CO2-equivalent/kg liveweight in 2,000 to below 2.5 kg CO2-equivalent/kg liveweight in 2017.
In ruminant systems the methane produced by enteric fermentation was by far the dominant source of greenhouse gases. With lamb, lowland production came out on top with the lowest carbon equivalent production resulting from more intensive management and increased growth rates.
Mr McAuliffe said: “As daily liveweight gain increases it is strongly negatively correlated with carbon footprint which means as an animal grows faster and performs better its carbon footprint tends to be lower than animals that perform more poorly.”