A ground breaking solution

A key element to meeting the net-zero challenge lies under our feet. By Gary Nairn.

Much of the net-zero debate ahead of COP26 in Glasgow is focused on reducing emissions. Yet in Australia we have a huge opportunity to drive outcomes on the other side of the equation, capturing carbon, which is why the government’s recent decision to include soil carbon sequestration as a key element in its net-zero 2050 plan is a very positive move.

The solution is under our feet. Australia has an abundance of soil that has been depleted of carbon over the past two centuries. At the Mulloon Institute, a not-for-profit regenerative farming organisation located just east of Canberra, we have a strategy not only to address this issue but in doing so to help deliver potentially substantial financial returns for agriculture and farmers.

Since 2018 significant parts of Australia have experienced what Dorothea Mackellar described in her poem, ‘My Country’, as “droughts and flooding rains” and “flood and fire and famine”. No better example of this was at Mulloon Creek Natural Farms, which straddles the Great Dividing Range. In 2018-19 this area experienced the nine driest continuous months since records commenced in the late 1800s. That was followed by the disastrous 2019-20 bushfires, with the top end of the Mulloon catchment totally burnt out. Since then, it has had two once-in-50-year floods.

When ‘My Country’ was first published in 1908 Mackellar wasn’t focused on CO2 emissions and their ramifications on climate. She was recording what she experienced. We now have similar experiences, albeit arguably more intensive. But Mackellar also wrote “green tangle of the brushes, where lithe lianas coil, and orchids deck the tree-tops and ferns the warm dark soil”.

With those words she was experiencing soils rich in carbon and that is certainly something we now have much less of. Scientists estimate we have lost between 40 and 60 per cent of our soil carbon over the past 200 years. Herein lies the opportunity with a net-zero goal. Unfortunately, much of our farming sector has been spooked into thinking that working toward net-zero will be detrimental to their livelihood. The opposite is the case.

The opportunity is now there to transfer carbon lost to the atmosphere and put it back where it belongs, in the soil. Carbon sequestration means healthier soils and more nutrient-dense food. Increasing soil carbon is one of the substantial strategies required to reach net-zero. Globally, soils contain more carbon than plants and the atmosphere combined. By regenerating soils, we can sequester more carbon underground and slow climate warming. And our farmers can earn income by doing that through the selling of carbon credits.

Key to carbon sequestration is water. A hydrated landscape will speed up carbon sequestration. The recent IPCC Report particularly highlighted a future with less rain overall but more intensive events risking flooding and erosion. Therefore, the better use of what rain does fall is crucial. In Australia 50 per cent of all rain is lost through rapid run-off or evaporation due to poor ground coverage. Rectifying this can be straightforward and not necessarily expensive.

The Mulloon Institute is demonstrating the potential in this approach in the Mulloon Creek catchment comprising 23,000ha with the support of more than 20 landholders. It is also one of just five global projects selected by the UN to assist in the development of guidelines for sustainable, profitable and productive farming.

TMI’s work has expanded to catchments in many parts of NSW, in North Queensland, WA, NT and soon Victoria. Demonstrating this work on the ground in partnership with communities helps farmers to understand the opportunity that landscape rehydration in conjunction with regenerative farming practices provides. According to the UN’s Food and Agriculture Organisation soils, if managed sustainably, can sequester up to 0.56 petagrams of carbon (or 2.05 gigatonnes of CO2 equivalent) per year, having the potential to offset yearly as much as 34 per cent of global agricultural greenhouse gas emissions.

In Australia agriculture comprises 13 per cent of our total emissions, so with our landmass, our farmers can contribute significantly to its reduction and at the current price of carbon of about $20 per tonne, but rising quickly, that is not just a goal or a slogan, it is a great opportunity for our agricultural sector to get on board for net zero.

Gary Nairn was a minister in the Howard government and is chair of The Mulloon Institute. This article first appeared in The Australian.