3 May 2024

Forest regeneration in Australia does not influence CO2 sequestration

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A study shows that restoration projects implemented in Australia have had a negligible impact on tree cover. A finding that openly questions the effectiveness of the national carbon market

by Matteo Cavallito

Forest regeneration projects conducted in Australia have reportedly proven ineffective in offsetting CO2 emissions. This is a problematic phenomenon in light of the long-standing emphasis on the carbon credit market, which is known to be based precisely on the ability of some specific initiatives to facilitate the sequestration of the element from the atmosphere.

This is suggested by a study conducted by the Australian National University (ANU) in collaboration with the company Haizea Analytics and the Universities of New South Wales (UNSW) and Queensland. The research, published in the journal Communications Earth & Environment, analyzed a total of 182 projects.

Forest restoration generated 37 million tons of credits

“Carbon offsets have been a central feature of climate policy in Australia for two decades,” the study explains. “Under a provincial mandatory carbon trading scheme (the world’s first) that operated in New South Wales and the Australian Capital Territory between 2003 and 2012 covered facilities were allowed to use offsets from designated project types to meet their emission reduction obligations.”

Each carbon credit placed on the market, the authors point out, is equivalent to 1 ton of CO2.

In this scenario, those related to native forest regeneration have become the most popular projects. Since the establishment of the trading mechanism, these have in fact generated 37 million credits, or 30 percent of the total circulating on the domestic market, covering nearly 42 million hectares, the study continues. This is the “the world’s fifth largest nature-based offset type by credit issuances, and the largest when projects involving avoided emissions are excluded.”

The study in Australia

The projects analyzed, which mainly affect inland drylands in Queensland, New South Wales and Western Australia, do not involve tree planting. In fact, the initiatives aim to regenerate native forests indirectly by reducing livestock and wildlife numbers. A controversial system, the authors note in a statement from the Australian National University, since much research in the country’s grasslands would, by contrast, show no major impact of grazing and animal presence in general on tree cover.

Studying satellite data available from 1988 to 2022, the authors assessed possible disparities in tree cover trends between project areas and adjacent areas. The results, said Andrew Macintosh, a professor at the Australian National Unoversity and co-author of the study, suggest that the projects “have been substantially over-credited and are largely failing.”

Tree cover increased less than 1 percent

The initiatives, he points out, produced more than 27 million credits over the observed period but, despite intentions, in the targeted areas “tree cover has barely increased at all and, in many cases, it has gone backwards. Almost 80 per cent of the projects experienced negative or negligible change in tree cover over the study period.”

In total, “The proportion of the total credited area, 3.4 million hectares, with woody cover increased by a mere 0.8 per cent over this time.”

And the impact on carbon sequestration? Not significant, the authors suggest: “The small increases in forest and woody cover, and the small effect of project registration relative to variation in cover in the comparison areas,” the study explains, “suggest human-induced regeneration projects have done little to help Australia meet its international mitigation obligations, both in absolute terms and relative to credit issuances.”

Climate change gets worse

According to Don Butler, another of the professors involved in the study, “the observed changes in woody vegetation cover are predominantly attributable to factors other than the project activities, most likely rainfall.” In sum, concludes co-author Megan Evans, of the University of Camberra, “The projects have largely failed to regenerate native forests and the evidence suggests things are unlikely to improve.”

And not without consequences: “Where carbon credits are issued to projects that do not sequester as much carbon as they are supposed to, it makes climate change worse. Credits from low integrity projects facilitate increases in emissions but the increases are not offset by reductions elsewhere.”