Net zero progress overblown by inconsistencies in land carbon accounting

This briefing by Zero Carbon Analytics argues that progress toward net zero is overestimated due to inconsistencies in how land-based carbon accounting is handled in Nationally Determined Contributions (NDCs) compared to IPCC methods. It highlights that current NDCs rely on unrealistic land-based removal targets that ignore ecological limits, social risks, and the declining ability of natural sinks to store carbon under rising temperatures.

• Harmonising the carbon accounting methods used in NDCs with those used by the IPCC would reduce the global carbon budget for limiting warming by 15-18%, effectively moving the net zero deadline forward by five to seven years.
• The amount of land pledged for carbon removal in NDCs is approximately 1 billion hectares, which is roughly two-thirds of global arable land and exceeds the area of China, creating significant risks for biodiversity 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, roughly half of Canada's 2023 carbon dioxide emissions from gas.
• IPCC Integrated Assessment Models (IAMs) are criticised for over-relying on land-based removal by assuming 'empty land' and ignoring technical, social, and economic barriers such as land tenure and human rights.
• A 2018 study found that IPCC scenarios limiting warming to 2°C project cropland for BECCS to expand by 8.8 million hectares per year, a rate more than three times faster than the historical expansion of soybean.
• Analysis of social and ecological risks suggests that a low-sustainability risk scenario could reduce the land available for carbon removal by approximately 79% compared to IPCC estimates.
• IAMs tend to underestimate the risks of climate-driven wildfire disturbances and the resulting erosion of the ability of forests to sequester carbon, leading to overly optimistic removal estimates.

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} }