Greenhouse gases and agriculture


New Zealand researchers have not yet identified mechanisms to substantially cut agricultural greenhouse gas (GHG) emissions, according to Dr Harry Clark, head of AgResearch's environmental research programme in New Zealand.

Addressing a Teagasc conference on agricultural GHG emissions in Wexford, he said - "This is a key issue for agriculture in New Zealand, given that the sector accounts for approximately 50 per cent of our GHG emissions." Dr Clark outlined how the New Zealand government is funding a very significant basic and applied research programme to address the issue of gaseous emissions.

Dr Frank O'Mara, Teagasc assistant director of agriculture research, told the conference that Ireland is now at a critical point in relation to the impact of climate change on the economy and on the agri-food sector. He argued that the current EU proposals for burden-sharing of the agreed 20 per cent cut in GHG emissions by 2020 and the renewable energy targets (20 per cent of total energy and 10 per cent of road fuel from renewables by 2020) are far more challenging than the Kyoto protocol.

In addition, he said - "There is likely to be less flexibility in meeting the new targets through carbon credits. These new targets come at a time when agriculture is at a turning point, with possibilities for growth - particularly in the dairy and tillage sectors. Growth in agricultural production is likely to bring emissions back close to 1990 levels."

Addressing the conference, Dr Cathal O'Donoghue, head of Teagasc Rural Economy Research Centre, said that global food demand, especially for livestock products, will increase significantly over the coming decades. He stressed the importance of ensuring that any measures to reduce GHG emissions from Irish agriculture do not result in emissions 'leakage' (movement of industry or production and the associated emissions from one country to another country not bound by emissions targets).

Thus, unilateral reductions in Irish food production will not contribute to solving the global GHG problem. On this basis, he made the case that agriculture should be treated differently from other sectors in terms of GHG emission targets. Loss to the economy must also be considered and, in particular, the impact at local level of constraining agricultural production to meet emission targets. Dr O'Donoghue argued that the effect of this will be greatest in the more remote regions, where there is a greater dependence on agriculture.

Strategies to mitigate the main agricultural emissions were discussed. It is clear that there is not a large mitigation potential at present in the agriculture sector. While several interesting strategies are being researched (e.g., nitrification inhibitors to reduce nitrous oxide emissions and dietary manipulation to reduce methane emissions), many of these are at an early stage of research or are uneconomic at present.

On the other hand, forestry can make a significant contribution by sequestering carbon and, if planting targets for renewable energy crops such as miscanthus and willow are met, it would make a significant contribution to meeting both the GHG and renewable energy target. However, doubt was expressed at the conference on the prospects of meeting these targets in the required timeframe, given the current low planting rates and the low farm profitability of these crops.

Delegates at the conference also heard how the agriculture sector should be credited for carbon sequestered biplants and for the production of bioenergy crops.

In addition, the conference stressed the importance of all systems of farming operating at the best level of technical efficiency possible, in order to reduce emissions. Teagasc research and advisory programmes focus at farm efficiency - delivering a win-win for farming and the environment.