University of Tasmania’s Matthew Harrison on soil carbon incentives

Farmers are concerned the Emissions Reduction Fund only rewards those with low soil carbon, not those who have managed the land well.

Farmers who have historically managed their soil well say they have little to gain financially from participating in soil carbon trading markets.

And the policy condition called “additionality” does not recognise the fact many farmers have been building their soil carbon and already contribute to a reduction in greenhouse gas emissions.

Under the Clean Energy Regulator’s Emissions Reduction Fund, farmers need to demonstrate that future soil carbon sequestration is greater than what it would have been had they not made any changes to their management.

University of Tasmania Associate Professor Matthew Harrison regularly meets with farmers across Australia to discuss ways to reduce greenhouse gas emissions and said “additionality” keeps coming up.

Additionality is the term used to describe the need to demonstrate that an intervention has improved soil carbon beyond what it would be in the absence of an intervention.

Prof Harrison said the idea of additionality is to ensure the carbon sequestered or the greenhouse gas emissions being avoided are additional to what would have occurred in the absence of an intervention or an ERF.

“Farmers that are coming to us suggest that the need for additionality really only rewards farmers who are starting from a low basal soil carbon. People who have historically managed their soil health and management well have little to gain financially from participation in soil carbon trading markets, particularly where their soil carbon stocks were nearing or at peak levels, of 5 to 6 per cent soil carbon,” he said.

Prof Harrison said the “good farmers” who have managed their soil well during the past 20 to 30 years don’t really have scope to improve soil carbon.

“But if you've degraded your farm, have low ground cover, no trees, and are starting from a low base, the potential for improvement is very high.”

While Prof Harrison said it made sense for those farmers who could prove additionality to receive remuneration for improving soil carbon from a low base, the Department of Industry, Science, Energy and Resources could consider paying farmers to maintain soil carbon.

“So it is like reverse additionality, so paying farmers to maintain soil carbon sinks in the landscape. If you remunerate people for that, you would probably see at the national scale, a relatively large chunk of emissions cut.”

However, he said some people become overly focused on carbon and being paid through an ERF isn’t the only advantage to good soil health.

“Carbon farming is really just good practice. If you build up soil carbon it is part of organic matter and it comes in a bundle, with oxygen, nitrogen and biodiversity, which provides a number of benefits to the soil by improving fertility and improving water holding capacity.”

“People should be more focused on the co-benefits of greenhouse gas emission mitigation rather than the carbon mitigation itself.”

Prof Harrison said they recently studied the extent to which soil carbon had improved since partial land clearing, which occurred in the late 1800s, for farmer Iain Bruce from Stanley in north-west Tasmania.

“Our modelling showed through good management practices (since the Bruce family took over the farmer in the 1970s), mostly through pasture management, had resulted in his soil organic carbon improving by almost 30 per cent in the top 30cm of soil.”

“This shows his scope to improve further was quite small.”

Mr Bruce told The Weekly Times he wanted to see the modelling because it showed there isn’t an unlimited opportunity to put carbon back into the soil.

“A lot of farmers have been managing soil carbon for a long time and are already positively contributing to reducing the effects of climate change, but there is currently no methodology to recognise that,” Mr Bruce said.

He said for him it wasn’t about the financial compensation, but about recognition in the policies and a holistic approach to tackling climate change.

Prof Harrison said a future ERF or government funding scheme, could think about payments for environmental stewardship or for avoided degradation of soil carbon.

“I’m not saying the government has to change everything but there should be a mechanism for thinking about avoided soil carbon loss in the same way there is avoided deforestation.

“For example, people that were going to cut down trees on their place, if they avoid it and enrol in an ERF they can get compensation.

“So the government could consider avoided soil carbon loss. That would be a credible mechanism for an ERF.”