Is the target achievable?
Studies around the world suggest that soil carbon can potentially be stored at a rate of 500 kg of carbon per hectare per year – slightly below the average target – by reducing tillage and planting legume cover crops.
These estimates change with soil type and climatic regions. Our research suggests that some cropland areas of the world have the potential to hit the 0.4% target, locally at least, through more modest overall increases in carbon storage. Restoring the soil’s carbon content in these areas is a win-win situation, as it will offset greenhouse gas emissions and boost soil quality at the same time.
One such place is Australia, where current soil carbon estimates suggest that the 0.4% target could be met by boosting soil carbon by just 220 kg per hectare – something that could easily be delivered in places that are not suffering drought.
The “4 per 1000” aspiration is an ambitious one, but perhaps even more important is the effect this initiative will have on promoting good soil management, which in turn can help to mitigate climate change. By encouraging farming practices that store more carbon, we can also help farmers improve the quality of their soils and boost food security at the same time.