DEAR EDITOR: I was delighted to read Prof Gerry Boyle’s article in the Irish Farmers Journal’s edition of 12 August when he concluded that “sequestration is potentially of enormous importance to farms,” and “when it comes to carbon, you can’t manage what you don’t measure”.

The ARC Zero project is about seven farmers who have made a significant start on their journey to net zero. Key to its success to date is the forensic focus on the principle that if you can’t measure, you can not manage. To that end, and recognising the vital role that sequestration, as well as emission reduction has in the net zero journey, ARC Zero has gone beyond current IPCC requirements, and beyond any other project of its kind on commercial farms in Europe.

Using the combination of detailed soil sampling and analysis, with an aerial LiDAR survey at 40 scans per metre square, we have tested and measured farm carbon stocks down to one metre deep.

This was done across different land uses and land managements, as well as measuring the above-ground carbon held in every tree and hedge on the seven farms.

All of these farms now have a really credible baseline of their carbon stocks, against which we will measure changes to the above and below ground carbon, when we repeat the surveys in five years’ time. This will allow ARC Zero to help the research community improve our current tier one sequestration factors and take them towards tier three sequestration factors, which will allow capture of actual change at the individual farm level, rather than the significantly less accurate methodology of averaging many farms together.

In addition, accepting that we did not use a national greenhouse gas (GHG) inventory approach, we have measured our emissions twice, using an accredited, whole business, lifecycle assessment calculator, called AgReCalc, supported by SRUC in Scotland.

All factors used in AgReCalc have IPCC approval so that our measurements have integrity.

We chose to use this, because as farmers, we don’t sell GHG inventories, we sell products.

So a whole business calculator, which can give us our individual product footprints, as well as our total business footprint, is the most useful to us as farmers, as we try to answer the relentless challenge coming from Government, processors, retailers and, ultimately, concerned consumers.

For those interested in wanting to hear and see more of our work, please do look at our website, www.arczeroni.org where you can view the video of the recent close-out conference of the first chapter of ARC Zero.