Oireachtas Joint and Select Committees

Tuesday, 2 November 2021

Joint Oireachtas Committee on Climate Action

Reduction of Carbon Emissions of 51% by 2030: Discussion (Resumed)

Dr. James Moran:

The Deputy asked about the science behind the payment metrics. Measuring the environmental quality of a piece of land is quite complex. Its environmental quality can be measured from the biodiversity or nature point of view. The soil quality and hydrological quality can be measured, as of course can the greenhouse gas balance. We have tried to capture the complexity of the science and distil it down into a few simple variables or metrics that can be measured on an individual field.

For example, we capture the nature value by looking at the composition and structure of the plants within a field and the overall sward, whether it is improved grassland, semi-natural grassland or other habitats, for example. Particularly in upland areas, we look at the extent of bare peat. We know that a greater level of bare peat leads to greater greenhouse gas emissions. Immediately a higher score will be achieved if the area is totally vegetated with little or no bare peat. On the other hand, if the area is extensively managed, there is a build-up of this litter level within the soil. We also measure the litter level that is visible to the farmer. Those are our soil quality variables.

We also look at water quality. We look at the risk of nutrient export and sediment loss from the farm. The pearl mussel project has looked at things like bare ground and the extent of riparian zones for example. This can be converted into a scoring system on a ten-point scale. In the same way that farmers, by looking at the tail bone and over the ribs of a beef animal in a mart can give a rough score of what the factory will pay for that animal, they need to be in the same position under a ten-point scoring system to know what the environmental performance of that field is. We then give a graduated payment level on a scoring scale of 1 to 10. It is exactly the same as with the Burren project.

The handbook on carbon farming from the European Commission that was published in June contains the variables we have been using for the past five or six years in the pearl mussel project and the hen harrier project. While this is going on, research projects in various universities ensure the scoring system we have correlates with improved greenhouse gas balances, soil quality, water quality and nature value.

The science has a role in understanding the complexity of this situation, by distilling that complexity down into simple variables that can be measured at farm level, understood by the farmer and, more importantly, are controlled and not subject to the vagaries of weather. We then link the payment rates to that. It is quite a simple system when it is broken down.