Farming the solution to becoming carbon neutral

In his inaugural lecture as Professor of Practice at Queens University Belfast, hosted in association with the Irish Farmers Journal, John Gilliland spoke about reaching net zero carbon on his farm and farms across the world.

John explained that net zero carbon on his farm means that the sum of his emissions equals the sum of his carbon sequestration or storage and this has been his long-term goal. He wants to see farmers paid to store carbon and to make sure that agriculture is seen as a solution in the battle against climate change.

The emissions he talks about include carbon dioxide, methane and nitrous oxide. Currently, farm emissions are calculated by adding these emissions together, but no account is made for carbon sequestration – the process by which carbon is taken in by plants and stored in trees or hedgerows or the soil.

John commented: “I know I have a farm and a landscape that’s full of plants that photosynthesise, that lock up carbon and release oxygen. I also know that our animals come along and graze some of that and re-release it, but not all of it if I do my job right. I’m really passionate that it isn’t just about reducing my emissions, that it’s actually about increasing my carbon stocks.”

John noted that the UK’s Climate Change Committee and the Intergovernmental Panel on Climate Change have said that to achieve net zero by 2050 we need agriculture not only to reduce its emissions, but to increase its carbon stocks.

If this is to happen, policy and regulation needs to help facilitate this. Carbon price in voluntary carbon markets needs to increase. John explained how at the EU DG Clima Workshop in 2021, it was stated that: “The current voluntary carbon price is too low to get farmers to change. The carbon price needs to approach that of the compliance market to get significant farmer behavioural change.”

Last week, the price for carbon on the EU emissions trading system stood at €83.18/t. However, carbon credits are traded for values of approximately €15/t on some voluntary markets.

What could a hybrid carbon framework look like for farms?

John explained that if a farmer created more carbon credits than were needed to reach their annual reduction requirement, they could sell that carbon as carbon credits in the next financial year. If, in the first five years of this carbon framework, a farmer did not reduce their net carbon position enough to meet their annual reduction requirement, that farmer would have to purchase carbon credits from a farmer who was selling carbon credits.

If it got to a stage where most farms were sequestering carbon and the sector was surplus in carbon credits, then these carbon credits could be offered to other sectors in the economy that still need to account for emissions released.

John noted that this prioritises the reduction of farming’s part of the national greenhouse gas inventory and minimises the risk of indiscriminate, mandated production caps or reductions being imposed.

How do we get to the carbon framework?

At present, measurements for carbon sequestration are not very accurate and are classified as tier 1. John explained that we need to get to a stage of very accurate measurement, which would be at tier 3. Tier 3 measuring would pick up on improved farming practices.

Tier 3 measuring would involve soil carbon testing to a depth of 30cm and using LiDAR technology (aerial imagery) to measure above ground biomass like trees and hedgerows.

John noted that every five years, soil carbon analysis and a LiDAR survey need to be repeated to work out the actual improvements on-farm and to allow for more accurate carbon sequestration calculations. Having this data means that farmers would be paid the full price for carbon and not a discounted price.

Other public goods

By carrying out LiDAR surveys to measure carbon, other things can also be measured that can benefit farms and the public.

For example, in the ARCZero project in Northern Ireland, where soil carbon is being measured and LiDAR is being used, the LiDAR survey has also given farmers run-off risk maps, which allow them to identify areas where nutrients are at risk of loss on the farm. It can also help measure biodiversity and habitat size and quality on farms.

Displaying a map of Hugh Harbison’s dairy farm, John explained that a series of yellow lines marked where water runs off his farm in extreme rainfall events, while red lines marked high levels of phosphorus on-farm.

Knowing this information allows farmers to put buffer zones, grass margins or hedgerows in place to try and prevent nitrogen and phosphorus contaminating water.

One major obstacle

However, at present there is one major obstacle to farmers selling carbon – carbon cannot be double counted. So, when governments include carbon sequestration from land, including farmland, in its national inventory of carbon emissions, that means that carbon has already been counted and so cannot be traded on a market.

John commented: “Carbon credits can only be sold once or used once. If a carbon credit is sold into a private carbon market, it cannot also be used to reduce GHG emissions.”

He explained that if a carbon credit is old into a market it cannot also be used in the national inventory.

Therein lies the nub of the issue. Testing for soil carbon is extremely expensive, as is LiDAR technology.

If farmers cannot be incentivised and paid a fair price for carbon, then how will carbon sequestration increase?