A trading system for carbon is needed to reduce carbon levels, including incentives at a private level, according to Alan Matthews, Professor Emeritus of European Agricultural Policy in the Department of Economics at Trinity College, Dublin, Ireland.

Soil contains a huge amount of carbon, twice as much as in the atmosphere in the 0-30 cm layer alone, he said, however continuous cultivation over a long period has reduced stocks of soil organic carbon (SOC) often to dangerously low levels.

He says that carbon sequestration, which involves the capture and storage of carbon, should be incentivised at a private level to reduce carbon emissions. He points to the Carbon Farming Initiative (CFI) in Australia, which allows farmers and land managers to earn carbon credits by storing carbon or reducing greenhouse gas emissions on the land. These credits can be sold to people looking to offset their emissions.

He says the big advantage in developing a compliance carbon offset market is that it would encourage the development of protocols for the measurement, reporting and verification of soil carbon changes.

Soil contains a huge amount of carbon, twice as much as in the atmosphere in the 0-30 cm layer alone, he says, however, continuous cultivation over a long period has reduced stocks of soil organic carbon (SOC) often to dangerously low levels. The EU’s Joint Research Centre estimates that some 45 per cent of the soils of Europe have a low or very low organic matter content (0-2 per cent organic carbon). “The main mechanism for soil carbon loss is associated with ploughing, due to increased decomposition of SOC due to soil aeration and soil aggregate destruction, increased aggregate turnover and a reduction in aggregate formation.

“Reversing this process to build up soil carbon stocks has the technical potential to sequester a lot of carbon. From a climate policy perspective, where the objective is to keep the carbon concentration in the atmosphere below a certain level, a tonne of carbon sequestered has the same value as a reduction in one tonne of carbon emissions,” he says.

In a presentation given to the Green Carbon: Making Sustainable Agriculture Real conference organised by the European Conservation Agriculture Federation (ECAF) in Brussels recently, he outlined five options for maintaining and restoring soil carbon:

  • counting soil carbon changes towards EU targets under climate change policy;
  • regulation, to require farmers and other land managers to maintain existing soil carbon or a minimum level of soil carbon;
  • cross-compliance conditions in Pillar 1;
  • voluntary agri-environment-climate measures in Pillar 2; and,
  • offset schemes linked to the Emissions Trading Scheme.