Australia’s carbon credit system has a new and rapidly growing source of flawed Australian carbon credit units (ACCUs). The “soil carbon” industry is small in scale, but it features the same problems as the increasingly discredited human-induced regeneration (HIR) industry which has produced tens of millions of carbon credits for carbon sequestration that there’s no evidence has taken place.
Soil carbon refers to increasing the storage of carbon in the soil, usually via increasing crop or pasture yields, and keeping the amount of carbon released from soil via decomposition to a minimum. Almost 480 soil carbon projects have been accredited under the government’s ACCU scheme, nearly two-thirds of which have commenced in the past two years, so the industry is in relative infancy, with only a few hundred thousand ACCUs issued.
But from later this decade, it will begin producing millions of ACCUs to be used as offset by heavy CO2 polluters continuing business-as-usual emissions.
A who’s who of Australian primary industries scientists recently outlined four critical failings of the current soil carbon methodology used by the Clean Energy Regulator.
Like HIR projects, changes in soil carbon levels are more likely to reflect external factors such as rainfall or drought than human interventions, which are the basis of crediting ACCUs. And when soil carbon levels fall due to drought or fire, for example, as with HIR projects, there is no requirement to hand back the generated ACCUs — unlike the emissions the ACCUs “offset”, which will remain in the atmosphere for thousands of years. The only recognition of soil carbon variability is a temporary 25% buffer that initially — but not permanently — reduces the number of ACCUs issued.
But in some ways, soil carbon is even riskier as a form of sequestration than HIR.
Independent measurement of soil carbon levels is far harder than assessing HIR, with project proponents able to pick the best samples from within projects to maximise results without detection, compared with satellite imagery that can identify tree regeneration for HIR projects. And assessment of soil carbon levels isn’t merely dependent on place but on time — projects commenced during drought will naturally record a significant increase in soil carbon levels after the end of drought and subsequent increases in rainfall.
As a long roster of scientists pointed out recently, some soil carbon projects have recorded increases in soil carbon far beyond those suggested as credible in scientific literature, including at unlikely soil depths. As the scientists note, the key problem is transparency, or its lack — just as with HIR.
“Scientists should be granted access to project data. Data could be used to improve models in order to distinguish between climate and management effects. This would ensure the method is fit for purpose,” they conclude.
As with HIR, however, there is minimal access to project data (the “voluntary” additional data provided by HIR proponents in response to criticism of those projects is nearly worthless) and efforts to provide rigorous independent verification meet with hostility from the Clean Energy Regulator and the industry.
The dismissal of strong evidence of the lack of integrity of HIR projects, and the lack of interest in identified and significant flaws in the soil carbon methodology suggests that the goal of the Clean Energy Regulator — acting under direction from successive governments — is less about the quality of ACCUs than the quantity, that the priority is producing a high volume of credits with a pretence of rigour that will be available to heavy emitters to continue polluting.
In other words, a government-regulated scheme to enable polluters to continue business-as-usual activities, with little actual offsetting and certainly no reduction in the overall level of emissions.
Using offsets doesn’t reduce emissions. Using credits sourced from soil carbon and HIR may guarantee they keep rising.
