Emissions in the Agricultural Sector

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Emissions in the Agricultural Sector


Figure 1: New Zealand's increase in air temperature

Agriculture is New Zealand's largest industry and along with food and forestry contributes 70 percent of the country's exports (Ministry for Primary Industries, 2013). Agriculture also provides important opportunities socially and economically by employing many, both directly and indirectly. Although Agriculture is a prominent and important sector in New Zealand there are many associated consequences. These include the emission of greenhouse gases such as carbon dioxide and methane gas and the impact they are having on the wider atmospheric envelope. Historically and also specifically in 2011, methane gas was the largest contributor, accounting for 49 percent of New Zealand's total emissions profile compared to globally, where methane contributes on average approximately 14 percent to each country's emissions profile (Ministry for the Environment, 2013). As Methane has been found to be 25 times more effective than carbon dioxide in trapping heat in the atmosphere, the specific focus of this informative webpage will be methane emissions (NIWA, 2013). Ruminant livestock such as cattle and sheep are the primary problem in terms of emitting methane along with smaller contributors such as fertilizers and pesticides. As a result of this, New Zealand has the highest per capita concentration of methane emitted which is approximately 0.6 tonnes of methane annually per person. Interestingly, this figure is six times the global average of per capita annual methane emissions (Landcare Research, 2013). Methane comes primarily from enteric fermentation in ruminant livestock, and sheep are the greatest single source.

Effects of carbon dioxide and methane in the atmosphere

Greenhouse gases such as carbon dioxide and methane gases are naturally released into the atmosphere, however, anthropogenic activities such as agriculture and the burning of fossil fuels has resulted in an enhanced greenhouse gas effect (Holden, 2008). This essentially prevents long-wave and reflected short-wave radiation from escaping the atmosphere resulting in an increase in global temperatures exceeding natural fluctuations (Figure 1). This also alters the radiative forcing of the earth, causing a positive in which there is more incoming energy and as a result the earth undergoes a warming. The agricultural sector produces the highest rate of emissions for New Zealand (Ministry for the Environment, 2013). This is mainly due to the process of enteric fermentation which is the production of methane through digestion in ruminant animals such as sheep and cattle (Ministry for the Environment, 2013). In 2011, enteric fermentation contributed to 32.3 percent of New Zealand's total emissions (Ministry for the Environment, 2013). Methane on a more global scale, however, is predicted to contribute 20 percent of the total estimated anthropogenic radiative forcing (Lassey, 2007).

Trends in environmental quality

New Zealand has a large agriculture sector, and this is reflected in its emissions profile which shows that agriculture contributes a high proportion of total emissions (Figure 4). Between 1990 and 2008 New Zealand's total net emissions increased by 63.2% which included a 9.3% increase for the agricultural sector (Figure 5)(Ministry for the Environment Greenhouse Gas Inventory, 2011). The increase in emissions in the agriculture sector in 2011 according to the Ministry for the Environment was mainly due to a higher dairy cattle population and an increase in the use of fertilizer containing nitrogen (Ministry for the Environment, 2011).

New Zealand's emissions profile is unique because of the large agriculture sector and therefore the higher amount of methane and nitrous oxide emitted compared to other developed countries (Ministry for the Environment, 2011). Methane and nitrous oxide contribute to approximately half of New Zealand's total emissions, whereas in other developed countries methane and nitrous oxide only make-up an average of about 12% of total emissions (Ministry for the Environment, 2011). As shown in Figure 2, enteric fermentation is the largest contributor of emissions in the agriculture sector. Therefore, enteric fermentation and methane are the main indicators of emissions from the agricultural sector and should be a focus for future research.

Figure 2: New Zealand's 2005 emissions profile

Figure 3: New Zealand's emissions from the agricultural sector

The increase in New Zealand's air temperature is shown in Figure 1 and is another indicator of increased greenhouse gas emissions. As mentioned earlier the global temperature increase can be attributed to the enhanced greenhouse gas effect; i.e. the release of emissions through anthropogenic activities. In New Zealand's case this is likely to be influenced by the large agricultural sector.

Figure 4 is New Zealand's total greenhouse gas emissions from 1990 to 2007; the graph shows an overall trend of an increase in New Zealand's greenhouse gas emissions since 1990. Furthermore, Figure 5 presents the contribution to emissions by the separate New Zealand sectors from 1990 to 2007. Figures 4 and 5 indicate that emissions in New Zealand and more specifically from the agriculture sector have increased since 1990 and this increase needs to be addressed. This could be attributed to the intensification of agricultural practices with growing economic demands.

Figure 4: New Zealand's total greenhouse gas emissions from 1990 to 2007 (source: Ministry for the Environment)

Figure 5: New Zealand greenhouse gas emissions by sector from 1990 to 2007

Drivers and pressures

There are many factors, both social and physical, driving emissions in the agricultural sector. The main driver of emissions is that agriculture is New Zealand's largest industry; therefore the majority of the country's emissions come from the agricultural sector (Ministry for Primary Industries, 2013). The ministry for primary industries have identified that the agricultural sector grows yearly at a compound rate of 3.3%. New Zealand's agricultural emissions have therefore increased by 1% since 1990 (Ministry for Primary Industries, 2013). This is a driver for emissions as the industry continues to grow and get more intensive. Similarly, the scale at which farming occurs has increased; overall there has been a dominant and overarching trend for an increase in agricultural intensification, as stocking rates increase and the extents of farming operations increase so too does methane emissions (MacLeod & Moller, 2006). New Zealand is also the main exporter of dairy and sheep meat, which puts pressure on the country to produce more meat (Ministry for Primary Industries, 2013). The agricultural sector provides a large number of jobs for New Zealanders, and along with the Forestry and Fishing industries provide a total of 150,000 jobs directly around the country (Federated Farmers,2013). Agriculture also employs many indirectly; tourist companies operate and promote their business on farming, providing both jobs and income. In New Zealand farming is also a part of the country’s national identity, and as a result there is the pressure to uphold this image.

However, there are also drivers influencing the agricultural industry, with a raft of recent legislation and voluntary agreements such as the Resource Management Act 1991, nitrogen caps and other policies farmers are being promoted to change the way they farm. Sustainability is starting to become a key theme for farmers as the effects of toxic chemicals and pushing the land too hard is starting to become evident. Organizations like Forest and Bird and Fish and Game are also pressuring farmers to protect unique land like wetlands and high country ecosystems. As a result farms are being pro-actively fenced, riparian planted and sections being covenanted to a greater degree. This acts as a further pressure, that is prompting farmers and people in the agricultural industry alike to increase the sustainability of respective practices. A final pressure that has had a big impact on the agricultural industry is the recent droughts and floods. This has caused farmers to realise that the earth is a dynamic system and vulnerable to changes like global warming. With the damage caused by last summer's drought the threat of global warming has become imminent. Farmers are now starting to realise that they need to actively take measures to reduce their greenhouse gas emissions and protect the earth and the wider atmospheric envelope.

Methods employed to address the issue

There have been a variety of methods proposed to decrease the amount of methane (and other greenhouse gases) New Zealand emits. These include; the Kyoto Protocol and The Emissions Trading Scheme, the "fart" tax, and government funded research into mitigation measures.

Respirators attached to free-ranging sheep (source: F Keliher; Landcare Research

Kyoto Protocol and Emissions Trading Scheme

New Zealand (as well as other developed countries) signed onto the Kyoto Protocol for the commitment period of 2008-2012 (greenhouse policy coalition) in 1997. The Kyoto Protocol is an international agreement created as a method for countries to reduce their greenhouse gas emissions as an active approach to addressing the issue of climate change. The overall agreement was that developed countries would reduce their total greenhouse gas emissions to a level ranging between 8% below or 10% above their 1990 emissions levels by 2012 (Ministry for the Environment, 2013). New Zealand agreed to a reduction to its 1990 levels along with accepting the consequences of exceeding the target since emissions since 1990 have increased (Ministry for the Environment, 2013). Under the Kyoto Protocol New Zealand also had to provide an annual inventory of the total greenhouse gas emissions to the United Nations Framework Convention on Climate Change, make regular updates on the country’s progress and mitigation measures, and cooperate with international arrangements (Ministry for the Environment, 2013). However, New Zealand has not signed up for the second commitment period of the Kyoto Protocol which is for 2013-2020, but is continuing with its own and other UNFCCC targets (Ministry for the Environment, 2013). It is unlikely that by not signing up for the second commitment period of the Kyoto Protocol that New Zealand's emissions will decrease. Without the pressure from an international authority it will be difficult to enforce and successfully implement policies to make a substantial attempt in decreasing the country's emissions.

As a method for reaching the Kyoto and other UNFCCC targets New Zealand created its own Emissions Trading Scheme which is administered by the Environmental Protection Authority (Climate Change Information, 2012). The Emissions Trading Scheme uses incentives for people who reduce their emissions and contribute to carbon sinks (Climate Change Information, 2012). Participants of the Emissions Trading Scheme are able to trade their emissions in order to reach the given target (Climate Change Information, 2012). The Emissions Trading Scheme encompasses a range of sectors that all have their own targets (Climate Change Information, 2012). There are a number of penalties for participants who do not abide, or provide adequate information regarding their emissions including fines up to $50,000 and imprisonment for up to 5 years (Climate Change Information, 2012). The Emissions Trading Scheme at first glance is an effective way of monitoring emissions, mainly because of the use of incentives and disincentives for abiding by the policy. However, the Emissions Trading Scheme allows sectors to trade their emissions, so if a certain sector has used all of their allowable emissions they are able to buy more off other sectors who haven't used up their allowance. Also, the creation of carbon sinks provides sectors with extra credit. The Emissions Trading Scheme uses the net emissions not the gross emissions. This means that factors such as carbon sinks offset emissions, allowing the gross emissions to be higher. By using net emissions, it defeats the purpose of reducing emissions because the sectors that are the highest emitters (i.e. are driving the increased emissions) are still able to emit substantially higher than the other sectors.

The 'fart tax'

In 2003, the New Zealand Government proposed a controversial 'fart/burp tax' in an attempt to reduce emissions (mainly methane) from the agricultural sector (NIWA, 2013). The tax would mean that all livestock farmers would be paying 60 cents per head of cattle and eight cents per sheep as 40 million sheep produce the same amount of methane as approximately six million cows(Bradford, 2003;Anderson, 2007). The money collected would be used to fund agricultural research efforts to help resolve New Zealand current emission problems especially methane and nitrous oxides. This was highly debated as agriculture is New Zealand's largest and fastest growing industry at present and farming communities were quick to protest. 64,000 farmers signed a petition against the proposed tax and around four hundred people including 20 tractors gathered outside parliament (Fickling, 2003). Federated Farmers President, Tom Lambie, agreed that the tax was yet another unnecessary cost for New Zealand Farmers which contributes greatly to the country's GDP and growing economy (Fickling, 2003). In 2007, there were further efforts by the New Zealand government to enforce the tax once again after the agricultural industry failing to cut back emissions (Anderson, 2007). This was a poor attempt by the government, however, it is a step in the right direction. The tax does not specifically address the problem and instead penalizes the farming communities for their way of life. The government should instead have created a more specific piece of legislation that is proactive with collaboration between farmers adn the government to find a balance between economic gains and environmental concerns - an integrated form of management which is holistic and realistic.

Current Research

There is currently quite a lot of research being undertaken to find ways of reducing agricultural methane emissions, there is however problems with funding so The New Zealand Government has established and funded a research centre - the New Zealand Agricultural Greenhouse Gas Research Centre - whose goal is to create ways for New Zealand to reduce its greenhouse gas emissions and meet international targets while still retaining high agricultural outputs (New Zealand Agricultural Greenhouse Gas Research Centre, 2013). Research is invasive and often involves attaching respirators and backpacks onto animals and connecting tubes to their rumens. Therefore it is difficult to quantify exact emissions and research is often difficult to conduct.

Current research into methane mitigation by the New Zealand Agricultural Greenhouse Gas Research Centre has included seven major research projects where the overall aim of ‘reducing emissions by manipulating the processes responsible for producing methane’ has been attempted. Under this the research centre has studies methane emissions of sheep and then attempted to produce a breeding program where animals with lower emissions are identified and used to breed lower emitting animals in the future. Other research includes the manipulation of methanogens (the micro-organisms within the rumen of livestock animals that produce methane) and other enzymes to suppress methane being produced; this can either be in the form of vaccines to inhibit methanogen or directly altering the rumen system of animals to be more efficient and emit less (New Zealand Agricultural Greenhouse Gas Research Centre, 2013). A purpose built facility in Palmerston North has found that methane levels can differ between 8 and 50% depending on feed (Ag Research, 2012). Research carried out by landcare research and NIWA has recently looked at directly quantifying the emissions with higher accuracy by analysing the micro climates and meteorology of paddocks where livestock are grazing (Landcare Research, 2013). Tentative research has also been carried out by Natasha Swainson through Massey University looking at the effectiveness of methane mitigation strategies and found that supplements fed to sheep did not significantly alter methane emissions but did find that sheep feed chicory yielded 17% less methane than sheep fed pasture (Swainson, 2011).

On a global scale, a study carried out in Australia showed that cows fed on poor quality pasture emitted 8% from gross energy consumed as methane whereas only 2% of gross energy consumed was emitted as methane by cows with a high grain diet (Harper et al.,1999). Alternatively in Argentina, researchers found that when feeding cows a high quality diet of alfalfa and clover instead of grains they detected up to a 25% decrease in methane emissions. However as highlighted earlier, New Zealand is unique, not only in emissions profiles but also in the way that farming is conducted. The vast majority of animals farmed in New Zealand are free ranging and live outside and are not housed inside or on feed lots as is the case in many countries. The climate in new Zealand also means that the types of feed grown and produced for animals is different to other countries so while studies may find that certain feeds produce less emissions this does not necessarily mean that New Zealand should change feed types without first researching and understanding the wider picture. Therefore studies conducted in other agricultural countries are not always necessarily applicable to the New Zealand context. Areas of further research have also been identified as studying and understanding all ruminant species and the rates at which they individually produce and emit methane instead of attempting to model methane emissions on a single ruminant species. Another research gap is in regard to the effects of diets and the digestion of different material in producing methane and stimulating methanogenic activity.

Research Needs and Conclusions

Adequacy of Available Information

Emissions from the agriculture sector are well-recorded through the Ministry for the Environment who create regular greenhouse gas inventories that show how much and what sectors New Zealand's emissions are coming from. New Zealand also has their own Emissions Trading Scheme which is a tool employed to account for participant's emissions. Although there is an adequate amount of available information on the actual emissions, there is not sufficient information on what mitigation measures are used to control/decrease the amount of emissions released from the agricultural sector. There has however, been numerous research undertaken for finding possible mitigation measures to be adopted. The credibility of sources used in this critical analysis may appear legitimate, however due to the lack of monitoring and trends being mapped there is little to prove that the indicators are not accurate.

Conclusions and Areas of Future Research

The issue of agricultural methane emissions is clearly evident in the trends illustrated above. There is no denying that New Zealand is emitting a significantly high proportion of emissions per capita. However the pressures and drivers affecting emissions are still weighted in favour of and balanced towards continuing to emit rather than mitigation at this stage. However increasing pressure to take responsibility for emissions is starting to gain leverage with farmers and the overall agricultural industry. With the increasing frequency of events suggesting the threat of global warming like extensive droughts and floods the agricultural has to accept that changes are in order to protect the future of agriculture.

The current state of knowledge of emissions from the agricultural sector provides much more opportunity for further research. The ethics of genetic modification and engineering are complex and questionable so such mitigation measures are unlikely to be formally adopted by the sector. Possible solutions that have been found are contentious and often only short-term solutions. While mitigation measures undertaken by other countries may be evidential New Zealand needs to develop more site specific solutions to measure and maintain methane emissions. Overall, there is a lack of research in long-term mitigation measures and solutions. In order for more tangible methods of reducing emissions to occur the nature of methane, trends and climate effects need to be understood in greater depth.

A large decrease in emissions from the agricultural sector in New Zealand is unrealistic because agriculture is one of the country's largest industries and contributor to the New Zealand economy. A decrease in New Zealand emissions while sustaining the local economy would entail a large change in the way of cleaner industries. Agreements like the Kyoto Protocol are warranted to ensure that New Zealand is held directly accountable and responsible for the emissions released by polluting industries like agriculture. More legislation is needed to ensure that New Zealand collectively reaches both lower methane and greenhouse gas emissions. More development could occur on iniatives like the agricultural emissions research levy (FART tax) to come to a fair and more agreeable outcome for both parties. New Zealand needs to start taking a proactive approach rather than acting reactively like what is the case with the emissions trading scheme. New Zealand needs to move away from schemes like the ETS and take resposibility for their actions rather than just throwing money at the problem.


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