Farm Ireland
Independent.ie

Friday 17 November 2017

Climate change is already happening but it's not all gloom and doom

Flooded land around the Shannon river as far as the eye can see near Athlone, Co. Westmeath.
Flooded land around the Shannon river as far as the eye can see near Athlone, Co. Westmeath.

Alan Matthews

A changing climate is yet another factor farmers must take into account in planning their activities.

While most recent discussion of the relationship between agriculture and climate has focused on agriculture's contribution to greenhouse gas emissions and how to ­mitigate these, climate change is already happening.

Mitigation today does not protect against the climate change impacts in the pipeline from past greenhouse gas emissions - impacts that will continue to unfold for decades to come.

The mean annual Irish surface air temperature has increased by approximately 0.8° Celsius over the last 110 years.

The number of annual frost days (where temperatures fall below 0°C) has decreased whilst the number of warm days (temperatures over 20°C) has increased.

There is some evidence that average annual national rainfall has increased by around 5pc in the period 1981 to 2010, compared to the 30-year period 1961 to 1990.

However, there is less agreement on how changes in rainfall patterns are changing spatially across the country.

There is also evidence that the growing season is now beginning earlier, with the timing of bud-burst for various tree species now occurring more than a week earlier than in the 1970s.

Also Read


These changes are expected to continue into the future. Met Éireann projects that average temperatures will increase by around 1.5°C by mid-century, with highest daytime temperatures projected to rise by up to 2°C.

Winters are expected to become wetter, while summers will become drier. Heavy rainfall events are expected to become more frequent especially during winter months.

These long-term changes in temperature and rainfall patterns will have an impact on the agriculture and forest sectors.

The Department of Agriculture, Food and the Marine has prepared a draft adaptation plan setting out the steps needed to eliminate vulnerabilities and to build resilience in the face of these climate changes.

The fodder crisis during winter 2012 and spring 2013, following heavier than average summer rainfall which resulted in limited and poorly conserved silage, together with a late spring, illustrates farming's vulnerability to extreme weather. The cost of this single fodder crisis was estimated to be around €450m.

There are positive impacts from our changing climate. There will be a longer grazing season with potentially significant increases in grass yield which will benefit the grazing livestock sectors.

Forest growth rates will be faster due to increased temperatures, although this may have an adverse impact on wood quality in the case of Sitka Spruce. However, crop yields - particularly for winter wheat and spring barley - will be negatively affected, even if yields of maize silage could benefit.

Heavier rainfall during the winter months could create increased compliance difficulties with the Nitrates Directive especially regarding slurry storage and land spreading.

Flooding and droughts

If land is waterlogged or flooded, it essentially means an extension of the closed period when slurry spreading is prohibited, causing a build up of slurry on farms.

At the same time, the likelihood of more frequent drought periods during the summer months could lead to increased meal/silage requirements and place additional demands on existing water supplies for agriculture.

There is also the potential for increased, uncontrolled wildfires during drier periods and associated loss of life. Other potential threats include the introduction and easier spread of new 'exotic' disease not currently found in Ireland.

Forestry may be adversely affected by more frequent storms with the potential to cause damage due to windthrow and windbreak.

Much of the adaptation to this changing climate will occur on-farm as farmers recognise the need to change their grazing practices, adopt new crop varieties, increase manure storage capacity and address water needs during dry periods. The draft adaptation plan notes how potato and vegetable growers are now more likely to cover root vegetable crops with straw mulch or to harvest potatoes earlier followed by controlled atmosphere storage to avoid loss of crops due to frost, in light of their experience during the winter of 2009/2010.

Government can help to facilitate adaptation in various ways.

An important role is the provision of better information. Long term, we need forecasts about likely climate impacts in different parts of the country.

In the short term tearly warning systems which can help to predict fodder shortages or provide better disease surveillance.

Addressing flood risk is the responsibility of the Office of Public Works and is not specifically addressed in the draft adaptation plan.

The flooding of the River Shannon is a particular issue, although there are no easy solutions.

Flooding cannot be eliminated, but various suggestions have been put forward as to how it might be possible to cope better in the future as the frequency of heavy rain storms is expected to increase.

Comments on the draft plan can be submitted to the Department of Agriculture, Food and the Marine up to January 27.

Alan Matthews is Professor Emeritus of European Agricultural Policy at Trinity College Dublin

Indo Farming