Study Projects CO2 Release From Australian Rangelands At 30-100 Million Tons By 2100

Intensifying extreme heat and drought due to the climate crisis will make Australia’s soil a net emitter of carbon dioxide, impeding the country from reaching its climate goals, new analysis has found.
Soil carbon sequestration has been identified as a way to help Australia meet its greenhouse gas emission reduction targets of 43% by 2030 and net zero by 2050.

But a study published in the Nature Portfolio Journal has estimated that median annual emissions from Australian soils will range from about 30 to 100 megatons of C02 over the next 80 years. The modelling is based on the prevailing “middle-of-the-road” global emissions reduction scenario. The report found net median soil carbon emissions during 2020-45 would be equivalent to 14% of the country’s total 2022 emissions, or 82% of agriculture emissions.

The report’s lead author, Prof Raphael Viscarra Rossel, said the “concerning” findings showed the substantial threat soil carbon losses posed to Australia’s emissions reduction targets. “If Australia wants to achieve its emissions reductions targets … that’s a significant amount of emissions that we’re not accounting for,” he said.

Soil carbon stocks fluctuate naturally with rainfall patterns but are also affected by land management practices. Drier and hotter conditions are associated with more soil carbon escaping into the atmosphere and lower rates of sequestration. Based on today’s land management practices, the report predicted agricultural areas would accrue as much as 0.19 tonnes of CO2 a hectare each year between 2020 and 2045. But by 2070-2100, the modelling found these gains would slow significantly because of rising average temperatures, and would not be enough to counteract “huge” soil carbon losses in Australia’s vast interior – known as rangelands – which are more sensitive to a warming climate.

EDIT

https://www.theguardian.com/environment/2024/apr/03/australia-soil-carbon-emissions-sequestration-report-net-zero