Farmers must carry their share of load

Comment by ALEXANDER GILLESPIE*

Farmer protests against a flatulence tax that would fund research into reducing methane emissions are regrettable. The spin being put on this issue by some interested parties seeks to mislead the public on important scientific, legal and policy facts.

The debate on methane has failed to note the significance of this gas - in particular, its build-up, its sources, and why it is different to the other greenhouse gases.

Globally, methane emissions are increasing. As of 2001, the atmospheric concentration of methane had increased by 1060 parts per billion (151 per cent) since 1750. The concentration of the gas at the turn of the 21st century had not been exceeded during the previous 420,000 years.

In global terms, these concentrations cause about a fifth of the so-called global warming - or "hot air", as the critics like to call it. But what this analysis omits is the fact that methane has also been linked to ozone depletion and air pollution. As such, methane emissions are connected to dirty air, burnt air - and hot air.

This problem is made worse because one litre of methane gas has a much greater disruptive impact on climate change than one litre of carbon dioxide. Although methane has a much shorter atmospheric lifetime than comparable gases such as carbon dioxide, on a molecule-for-molecule basis it is much more effective at trapping the sun's heat. Hence, it has a much higher global warming potential.

Accordingly, making a percentage reduction in methane emissions over the near term will have a much greater impact than making a comparable reduction in carbon dioxide emissions over the same period.

The reason methane was not singled out previously in international negotiations is that the other regimes waited until the climate regime was in place, because methane is more of a primary pollutant in global warming, as opposed to being more a secondary pollutant in regard to ozone depletion or air pollution.

The regime now dealing with methane is the Framework Convention on Climate Change and its associated Kyoto Protocol. As a generalisation, the obligation for industrialised countries under the protocol is for a 5 per cent reduction of their greenhouse gas emissions from what they were at 1990.

But thanks to the strong efforts in these negotiations by countries like New Zealand, these reduction obligations are not gas-specific. Each country is obliged to make a cumulative reduction of its overall gas output but the percentage reduction is not tied directly to any one gas.

This clever legal footwork saved industries such as agriculture from being singled out for any specific international targets.

But the result of this escape is that other sectors within a country will now get enhanced costs for the overall reductions cast upon them. Thus, although New Zealand will make its overall reduction target, some sectors in society - that is, the non-farming sector - will have to make greater reductions in other greenhouse gases to offset the agricultural sector's disproportionate methane emissions.

Exactly how this approach squares off the polluter-pays principle and an ethos of individual responsibility - whereby if someone causes a problem, he or she should bear a proportionate response in rectification - is a matter of debate.

What should not be a matter of debate is that the farming sector should take the lead in shouldering scientific investigation in how to confront methane emissions.

To argue against this reflects a clear lack of appreciation of the rest of the burden that New Zealand as a whole will carry to deflect its pollution.

It is also being spun that reductions in methane emissions are difficult to achieve. This is a half-truth. Reductions are possible and clever scientific discoveries are offering more potential all the time. For example, within the European Union, methane emissions fell 17 per cent between 1990 and 1998. This was mainly the result of reductions in emissions from agriculture and landfills.

Further reductions are projected (up to 30 per cent by 2010 from 1990 levels) provided that existing policies and measures are fully implemented.

In addition to all of the developments that are making reductions in other methane-related areas, it has been shown that changing the diet of ruminants where possible - via the upgrading of low-quality forages - will decrease the amount of methane produced for each unit of animal weight.

For example, in the European Union, diet changing (via infusing a dose of methane-eating bacteria) may reduce methane emission from sheep by up to 17 per cent. If this could be adopted over Europe, the continent's methane emissions would fall by 4 to 5 per cent.

Obviously, such practices may not be applicable here. Nevertheless, scientific discoveries are beginning to show that options are available. In some instances, science is showing these options are unique.

For example, it may be possible to make methane reductions by taming the emissions of other pollutants. Removing carbon monoxide (a notorious pollutant from cars) from the air can help the hydroxyl radical to maintain its presence in the atmosphere.

The joy of hydroxyl is that it is a cleaning agent with a primary role to play in removing methane from the atmosphere.

Likewise, it has been shown that bacterium from acidic wetlands removes methane from the atmosphere. But the bacterium itself is often under threat from industrial pollutants. In both instances the moral of the story is the same: reduce certain other pollutants and natural processes may take a lead in confronting methane.

Methane has multifaceted links to a number of environmental problems. It is disproportionately the responsibility of the agricultural sector, but the whole country will be carrying the burden to make the weight of this responsibility less for farmers. The least they can do is to take a front role in assisting with research.

The scientific possibilities are promising, and linkages are now showing that thinking holistically about these problems may, in some instances, solve two problems at the same time.

This is a much more promising approach than denying responsibility for the issue.

* Alexander Gillespie is an associate professor in Waikato University's law school.