14 September 2012

7 minute read

This section summarises the high level findings of the New Zealand Beef GHG Footprint Study, including the significant sources of emissions and opportunities for emissions reductions.

Overall Findings

Overall GHG component profile

The total GHG footprint was calculated at 2.2kg CO2-equivalents (CO2-e) for a 100g portion of beef meat. This can be broken down into 90.3% for the on-farm stage, 2.1% for meat processing, 4.2% for transportation/storage and 3.3% for the consumption phase. This overall breakdown of the GHG footprint and the dominance of the on-farm component are broadly consistent with other studies of products derived from pastoral farmed ruminant livestock.

On Farm

On-farm GHG component profile (smaller pie is the overall footprint; see Fig. 1)

On farm, the largest contributors to the GHG footprint are natural processes associated with cattle consuming pasture. These processes produce methane from rumen digestion of pasture (via belching, 62% of total footprint) and nitrous oxide from animal excreta on soil (17% of total footprint).

It is possible to reduce the on-farm component of the beef meat GHG footprint through management practices that increase the conversion of pasture to meat and thereby reduce the proportion of pasture consumed to “maintain” the herd. The study examined a range of management options that could reduce the GHG footprint of beef, using an on-farm case study.

Emissions from external inputs to farms – such as fertiliser, fuel and electricity – are small, due to the low intensity and low input nature of beef farming in New Zealand. For example, electricity use contributed less than 0.3% of the total footprint. This is partly due to low electricity usage, but also because New Zealand’s electricity generation mix is high in renewable sources. Nonetheless, further reductions in emissions from electricity are being created on some farms through the deployment of technology, such as micro-hydro generation. Also, unlike other, more intensive overseas farming systems, the use of energy-demanding nitrogen fertilisers on New Zealand beef farms is very low. Instead, New Zealand beef farmers rely heavily on clovers in pastures, which use sunlight’s energy to fix atmospheric nitrogen and produce no direct GHG emissions.

On-Farm Case Study:

The study examined a small range of possible GHG footprint reduction initiatives in the context of actual farm models provided by Landcorp Farming. These initiatives included:

• Increase the calving rate of beef cows from 90 to 95%.
• All beef cows replaced with a once-bred heifer system, where heifer calves (Hereford/Friesian cross, derived from the dairy sector) are brought in as weaners in late spring at 100kg liveweight. These heifers are reared, have a calf (which is reared to finishing stage) and are sold for processing after a short period of weight gain.
• All beef cattle are replaced with an all-steer purchasing/finishing system, which involves buying in weaner steers (Hereford/Friesian cross) in late spring at 100kg liveweight and finishing them at 300kgplus carcass weight.
• All beef cattle replaced with a bull beef system, based on Friesian bulls (from the dairy sector) purchased as 100kg weaners in late spring and finished at 300kg carcass weight.
• Nil nitrogen fertiliser use (from an already low input), with pasture and animal production decreased, based on an assumed reduction of 10kgDM per kg N applied.

Of these scenarios, the biggest reduction potential came from increasing the efficiency of beef production. Measures such as deriving beef from the dairy sector, as well as improved growth rates from bull beef compared to steers or heifers resulted in reductions in farm-related GHG emissions of up to 30%. Other strategies were estimated to provide only a small reduction. (For example, a 5% reduction from ceasing use of N fertiliser on pasture.)

Meat Processing

Processing GHG component profile (smaller pie is the overall footprint; see Fig. 1)

Meat processing made up only 2.1% of the total beef GHG footprint. This was mainly from energy use and wastewater processing. Electricity, as well as a range of fossil fuels, is used across different plants largely for hot water and steam production. The main use of electricity is for chilling or freezing meat. Electricity is also used to operate machinery and for lighting and wastewater treatment. Methane and nitrous oxide are emitted during some wastewater processes.

The meat processing stage is only a small part of the GHG footprint, but it is an area over which industry has direct control and where technologies are available to reduce emissions. While progress is being made on reducing energy use, meat products will always need to be refrigerated and there will always be a need for hot water and steam (for hygiene reasons). For these reasons, there will be natural limits to how far energy efficiency can reduce the footprint.

The meat processing GHG footprint can also be reduced through the use of loweremission energy sources. Since 1990, the meat industry has reduced its use of coal, through improved efficiency and the deployment of lower-emitting energy sources, including natural gas, wood chip and other biomass-fired boilers.

Wastewater processing is also becoming more emissions efficient, with less use of anaerobic pond systems (that produce methane) and more use of land application of wastewater. The latter reduces emissions and has the added benefit of capturing nutrients for pasture or crop production, rather than allowing those nutrients to escape and potentially degrade natural waterways. The study examined the impact of several scenarios on GHG emissions from processing.

Processing Energy and Wastewater Scenarios

Several scenarios associated with energy and wastewater treatment in the processing stage were examined. Highlights were:

• Switching from an anaerobic waste treatment system to aerobic treatment decreased processing emissions by 19-22%.
• Capturing and flaring methane from anaerobic waste treatment systems decreased emissions by about 30%.
• Further decreases (38%) were made when the captured methane was used for energy. This was due to a lower use of natural gas and lower methane emissions.

However, because meat processing contributed only about 2% of the total GHG emissions, even the scenario with the largest impact resulted in only a 1.2% decrease in the whole GHG footprint.

Transport and Storage

Transport and storage GHG component profile (smaller pie is the overall footprint; see Fig. 1)

Oceanic shipping of beef in refrigerated containers from New Zealand to overseas’ destinations (based on the relative global distribution) made up about 2.6% of the total footprint; this is the main contributor (about 61%) to the transport and storage stage. While shipping is an important source of emissions, the relative size of this figure highlights that transportation distance influences only a small fraction of the total footprint. Focusing solely on this small fraction is an inappropriate and potentially misleading means of assessing the overall impact of emissions from a product.

Repacking and processing meat in Regional Distribution Centres (RDC) made up about one-third of GHG emissions in this stage, mainly due to the materials used and the time meat spent in storage.

Other transportation components included road transport of meat from the processing plant to the wharf, wharf to RDC and finally, to restaurants.

Consumption Stage

Consumption GHG component profile (smaller pie is the overall footprint; see Fig. 1)

The consumption-related components of beef eaten in a restaurant contributed 3.3% of the total GHG emissions. Cooking made up more than half of the emissions from this stage, while emissions from dealing with waste also contributed significantly.

The transportation component of the consumption stage – diners travelling to and from the restaurant – was excluded from this study, as required by the PAS2050 method. To provide some context, however, had the consumer transport (in this case, using a conventional automobile to reach the restaurant) been included in the study, it would have added another 13% to the total footprint – more than five times the emissions for oceanic shipping and more than seven times the emissions from the entire processing stage.

This figure highlights that consumers can play a significant role in reducing the total life cycle GHG footprint of food products – and at relatively low cost. For example, if the consumer used a low CO2 emission vehicle instead of a conventional automobile, the whole footprint decreased by about 0.1kg CO2-e per 100g portion of meat – a reduction that equates to about 2.4 times the total emissions from processing the beef in New Zealand. The study also examined the impact of increasing the percentage of noneaten wastage, from a baseline of 10%, to 20%. This increased the consumption emissions by nearly 10%.

These results highlight that changes outside the direct control of the New Zealand beef industry, can have significant effects on the GHG footprint. There is a need to consider not just the emissions at the production and processing stages of products, but also aspects such as consumer behaviour, when looking at how the whole GHG footprint of products can be reduced.

September 2012