Net zero progress overblown by inconsistencies in land carbon accounting

The document examines how discrepancies between NDC accounting and IPCC standards lead to an overestimation of land-based carbon sequestration, potentially reducing the global carbon budget by 15-18%. It highlights that current NDC pledges for land-based removal involve approximately 1 billion hectares, which the author claims is impossible without threatening food security and biodiversity. Furthermore, the briefing critiques IPCC Integrated Assessment Models (IAMs) for ignoring land tenure, human rights, and the declining ability of natural sinks to store carbon under rising temperatures, suggesting that sustainable removal potential is up to 79% lower than IPCC estimates.

• Harmonising the carbon accounting methods used in NDCs with those of the IPCC reveals that the global carbon budget for limiting warming is actually 15-18% smaller, which effectively moves the net zero deadline forward by five to seven years.
• Current NDC pledges for land-based carbon removal require approximately 1 billion hectares of land, roughly two-thirds of global arable land, a scale the document asserts is impossible without causing catastrophic impacts on biodiversity, human livelihoods, and food security.
• Canada's carbon accounting excludes emissions from 'unmanaged' forests, which comprise about 34% of its forests; between 2005 and 2021, this resulted in the exclusion of approximately 114 million metric tonnes of emissions annually.
• IPCC Integrated Assessment Models (IAMs) are criticised for unrealistic assumptions, such as projecting BECCS cropland expansion at 8.8 million hectares per year—over three times the historical expansion rate of soybean—while ignoring land tenure and human rights issues.
• Analysis of social and ecological risks suggests that the sustainable potential for land-based carbon removal (3.3 to 3.8 billion tonnes per year) is significantly lower than IPCC Sixth Assessment Report estimates (15.6 billion metric tonnes per year), potentially reducing available land for removal by 79%.
• IAMs tend to underestimate the risks of climate-driven feedback loops, such as the interaction between wildfires and climate change, which erodes the ability of forests to sequester carbon more quickly than models predict.

APA

Team, Z. (2024). Net zero progress overblown by inconsistencies in land carbon accounting. Zero Carbon Analytics. https://zerocarbon-analytics.org/insights/briefings/net-zero-progress-overblown-by-inconsistencies-in-land-carbon-accounting/

Chicago

Team, ZCA. Net zero progress overblown by inconsistencies in land carbon accounting. Zero Carbon Analytics, 2024. https://zerocarbon-analytics.org/insights/briefings/net-zero-progress-overblown-by-inconsistencies-in-land-carbon-accounting/.

Wikipedia

{{cite report |last1=Team |first1=ZCA |title=Net zero progress overblown by inconsistencies in land carbon accounting |publisher=Zero Carbon Analytics |date=18 November 2024 |url=https://zerocarbon-analytics.org/insights/briefings/net-zero-progress-overblown-by-inconsistencies-in-land-carbon-accounting/ |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{team2024net, author = {Team, ZCA}, title = {{Net zero progress overblown by inconsistencies in land carbon accounting}}, institution = {Zero Carbon Analytics}, year = {2024}, month = nov, url = {https://zerocarbon-analytics.org/insights/briefings/net-zero-progress-overblown-by-inconsistencies-in-land-carbon-accounting/}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }