Towards a science-based definition of unabated fossil fuels

The briefing highlights the lack of a widely agreed-upon definition for 'unabated fossil fuels' despite the term's centrality in G7, G20, and UN climate negotiations. It warns that ambiguous definitions may allow for low carbon capture rates and the exclusion of upstream emissions, potentially stalling climate progress. The author proposes a science-based definition requiring near-total carbon capture (90-95%), permanent geological storage, near-total elimination of upstream and transport emissions, and rigorous third-party verification.

• The term 'unabated' has become a central point of international climate diplomacy, appearing in G7, G20, and UN Framework Convention on Climate Change agreements since 2021, yet it lacks an official, universally agreed-upon definition.
• Current global carbon capture and storage (CCS) capacity is extremely limited, accounting for only 0.1% of global fossil fuel emissions, meaning 99.9% of such emissions currently come from unabated fossil fuels.
• Existing definitions from the IEA and US Special Envoy John Kerry are considered problematic because they do not specify minimum carbon capture rates and exclude upstream emissions, which represent nearly 15% of total energy-related greenhouse gas emissions.
• Real-world CCS projects often fail to achieve high capture rates; examples include the Boundary Dam plant in the US at 65%, the Gorgon facility in Australia at 45%, the Quest refinery in Canada at 39%, and the Century Gas Processing Plant in the US at under 10%.
• A science-based definition of abatement must require carbon capture rates of at least 90-95%, permanent underground geological storage, and the virtual elimination of upstream and transport emissions, specifically targeting methane intensity levels of 0.5% or lower.
• To align with the 1.5°C warming limit, the use of fossil fuels that do not meet stringent abatement requirements must be reduced to a minimum by 2050, with the IEA's Net Zero Emissions scenario projecting an 87% drop in total coal, oil, and natural gas use by that date.

APA

Team, Z. (2023). Towards a science-based definition of unabated fossil fuels. Zero Carbon Analytics. https://zerocarbon-analytics.org/uncategorized/towards-a-science-based-definition-of-unabated-fossil-fuels/

Chicago

Team, ZCA. Towards a science-based definition of unabated fossil fuels. Zero Carbon Analytics, 2023. https://zerocarbon-analytics.org/uncategorized/towards-a-science-based-definition-of-unabated-fossil-fuels/.

Wikipedia

{{cite report |last1=Team |first1=ZCA |title=Towards a science-based definition of unabated fossil fuels |publisher=Zero Carbon Analytics |date=23 November 2023 |url=https://zerocarbon-analytics.org/uncategorized/towards-a-science-based-definition-of-unabated-fossil-fuels/ |access-date=17 August 2026 |via=Climate Insights Directory}}

BibTeX

@techreport{team2023towards, author = {Team, ZCA}, title = {{Towards a science-based definition of unabated fossil fuels}}, institution = {Zero Carbon Analytics}, year = {2023}, month = nov, url = {https://zerocarbon-analytics.org/uncategorized/towards-a-science-based-definition-of-unabated-fossil-fuels/}, urldate = {2026-08-17}, note = {Indexed by Climate Insights Directory} }