When I was asked to chair the Climate Change Advisory Council (CCAC) in the summer of 2015, I thought my most difficult task would be explaining to farmers that they had to give up on cattle and dairying because the methane cows emit is a very damaging greenhouse gas.
However, before the council got up and running, I discovered that the science told a more nuanced story.
Methane is a short-lived gas that is very damaging for climate. However, it disappears quite quickly from the atmosphere. If we reduce methane emissions it will help cool the planet. By contrast, the carbon dioxide we emit stays in the atmosphere indefinitely. Even if we reduce our carbon dioxide emissions, we are still making things worse while we emit any of the gas.
Recognising the difference in longevity between methane and carbon dioxide, a scenario developed for the CCAC by Teagasc models a very substantial reduction in the beef herd, with continuing milk production out to 2050. Because the agricultural sector makes almost nothing from beef, while milk is very profitable, such a change would not greatly affect farm incomes.
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However, by substantially reducing the methane emissions from cattle, this approach would reduce the sector’s impact on the global temperature. If the land freed up by reducing cattle numbers was then used to grow trees, which reduce carbon dioxide in the atmosphere, by the 2040s Irish farming could be part of the solution to global warming, rather than being part of the problem.
So while farming has to make big changes to tackle global warming, we won’t have to eliminate all cattle from our fields while aiming to halt our contribution to climate change.
We also need to dramatically reduce the use of agricultural fertilisers because they result in large emissions of another greenhouse gas: nitrous oxides. This gas, like carbon dioxide, remains in the atmosphere for a particularly long time. Thus every tonne of fertiliser used adds to the problem of global warming.
Fertiliser use is also a big factor in the pollution of our rivers and lakes. So cutting fertiliser use would bring a double benefit: cleaner rivers, and reduced emissions.
If the EU drops our derogation on nitrogen emissions, it would force a substantial improvement in our environmental performance, at a time when the EPA has called out the deterioration in water quality. Multispecies swards – grasslands with a mix of grasses and herbs – that fix nitrogen in the soil can keep soils productive at reduced fertiliser levels.
The CCAC has consistently advised that farming needs a programme of change to address emission concerns (and water pollution). Scientists in UCC and University of Galway have recently again emphasised the very damaging nature of methane for climate. This is consistent with the approach taken by the CCAC.
However, some of these scientists also argue that Ireland should essentially end all livestock production, and that the Teagasc scenario, of some continuing dairy farming, should be rejected by the climate council. Scientists argue it is unfair to the rest of the world for us to use up some of the limited allowable world quantity of methane emissions.
While I fully accept the scientific advice of the experts on methane, what I cannot accept is their economics. Essentially they argue that a fair outcome would be one where everyone in the world is allowed to emit the same quota of methane, irrespective of the efficiency per unit of methane of the food production concerned.
Someone living in the Sahara would be allowed to produce a small quantity of milk, while a farmer in Cavan could produce a small quantity of rice (another big cause of methane emissions).
Such a policy makes no sense. Dairy products are best produced in temperate zones where the methane emitted per unit of output is lowest. Similarly, rice is best produced in southeast Asia, rather than in our climate.
If everyone in the world were given the same quota of methane, and allowed to trade it, ultimately production of dairy products and rice would end up where it is now. However, the bureaucracy needed to allow this efficient outcome would be unworkable.
So the current advice from the CCAP on handling agricultural emissions in setting our targets is the right one.
There is, of course, a strong argument that Ireland, one of the richest countries in the world, has a duty to help countries in Africa and parts of Asia to deal with the challenge of global warming. But this is best done by using Irish taxes to transfer additional resources to those who most need it, via our aid budget.
