The decarbonization identity and pathways to net-zero

Thesis

Success or failure of climate policies in limiting warming to beneath particular thresholds depends on several physical, economic and social uncertainties. Whilst scenario analysis can be informative as to the types of policies that are required to achieve these goals, the complexity of scenario analysis often masks the underlying fundamental choices. This dissertation introduces the concept of the ‘decarbonization identity’ to simply and systematically describe the mutually exclusive and collectively exhaustive range of choices available in future climate policy decisions. The simple identity states that the remaining carbon budget [B] for a given level of warming can be partitioned into four areas: the already committed ‘baked-in’ emissions from existing capital stock [E]; new commitments arising from investments in additional capital stock yet to be made [N]; less the stranding of existing or future capital stock [S]; and the additional atmospheric space created by negative emissions technologies (NETs) [A]. This dissertation finds that currently operating electricity generators [E] would already emit more CO2 (~300 GtCO₂) then is compatible with currently available generation-only carbon budgets [B] for a temperature rise of 1.5-2°C (~240 GtCO₂). In addition, the current pipeline of planned fossil fuel power plants would add almost the same amount [N] of emission commitments (~270 GtCO₂) to this capital stock again. Finally, these carbon budgets are inherently uncertain and depend on future, yet to be achieved, reductions of short-lived climate pollutant (SLCP) emissions. Should those reductions not be achieved today’s remaining carbon budgets could be up to 37% smaller. Policymakers have now five choices to achieve the Paris climate goals: (1) protect and enhance carbon budgets by early and decisive action on SLCPs; (2) retrofit existing power generators with carbon capture and storage (3) ensure that no new polluting capital stock is added; (4) strand a considerable amount of global electricity generation capacity; and (5) create additional atmospheric space by scaling up NETs. Over the coming years and decades, the challenge will be to identify the most efficient balance of these options.

Authors: Pfeiffer, A

• Alternative title: The scale and impact of committed cumulative carbon emissions and stranded assets in the electricity generation sector on the decarbonisation of the economy
• DOI: 10.5287/ora-kznmg2vv6
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: committed emissions; carbon budgets; climate change; atmospheric sciences; environmental economics; global warming; power generation; energy; stranded assets; decarbonization identity
• Subjects: Geography and the Environment; Stranded Assets