THE United Nations has thrown its support behind soil carbon, but Australian attempts to create a market mechanism to reward the building of soil carbon reserves are still mired in complexity.
The United Nations Environment Program's (UNEP) 2012 yearbook stated building the world's soil carbon stocks was an urgent necessity.
About 60 per cent of the carbon held in the soil in the 19th Century had since been lost to land use changes, UNEP estimated, with much more to come if forests, grasslands and peatlands continued to be destroyed.
Destruction of soil carbon creates double trouble. The release of carbon into the atmosphere increases the potential for global warming, thus climate change, while reducing the capacity of soils to withstand the effects of climatic extremes like drought and flood.
Both sides of Australian politics agree on the notion of building soil carbon, albeit with different mechanisms.
The Coalition's soil carbon program, which underpins its whole emissions reduction strategy, limits sales of soil carbon offsets to the voluntary market.
Labor's Carbon Farming Initiative (CFI) is more ambitious, with the intention of creating a robust, well-audited framework for generating emissions credits from farming in ways that satisfy both voluntary schemes and the international carbon market.
But a soil carbon methodology was yet to be pushed out the gates by the CFI's Domestic Offset Integrity Committee (DOIC). The gulf between the variable ecological processes that shape soil carbon, and the market's need for certainty, is not easy to bridge.
If marrying natural processes to the financial market wasn't complicated enough, the CFI's aspiration to link in with international carbon markets also demanded methodologies comply with rules laid down under the international Kyoto agreement.
Some of those Kyoto-based rules were muddying an already complex process.
The Carbon Farming and Trading Association (CFTA), an arm of the non-profit lobbyist Carbon Farmers of Australia, said under its current brief the CFI may force farmers into an "additionality trap".
Kyoto's additionality rule disqualifies landholders from selling emissions offsets from any activity regarded as "business as usual".
In more formal terms: "For a project to deliver genuine carbon abatement, it must result in a reduction in atmospheric greenhouse gas that is additional to what would have occurred in the absence of the project."
CFA's Michael Kiely warned that landholders who have already begun using techniques or tools aimed at enhancing soil carbon may be in the future disqualified from harvesting offset revenue if this rule was taken literally.
Publicity around soil carbon meant many landholders were moving to carbon-friendly techniques, for both soil carbon's intrinsic benefits and the potential of extra revenue downstream.
Their efforts are often supported by well-meaning natural resource management groups, Mr Kiely noted.
The "additionality trap" also disqualified farmers in areas where the offset practices have become common practice.
If more than 5 per cent of farmers in a district or industry segment have adopted the practice, "new adoptees are deemed to not be motivated by CFI considerations and any abatement arising would have happened anyway".
"Local natural resource management bodies engaging farmers in certain districts in 'soil carbon trials' not only endanger participating farmers, but all others in the district," Mr Kiely said.
He also questioned whether the rule may compromise farmers involved with the federal government's $99 million Action On The Ground program.
The program's stated goal was to "to assist landholders trial and demonstrate ways to reduce agricultural greenhouse gas emissions and/or increase carbon stored in soil".
"But farmers who change their practices as part of these trials before they are registered in an offsets project through an approved methodology will almost inevitably make themselves ineligible to earn offsets that they can trade," Mr Kiely said.
"This holds even if they had decided to make the change prior to their involvement in the Action On The Ground program."
So far, Mr Kiely said, the Commonwealth had not confirmed with the CFTA whether this was indeed the case.
And last week the CFTA's methodology, the only soil carbon methodology formally known to be submitted to DOIC, was knocked back for technical reasons.