Editing IPCC:AR6/WGIII/Chapter-16 (section)

==== 16.2.4.3 Implications for the Modelling of Technical Change in Decarbonisation Pathways ====

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Although the debate is still ongoing, preliminary conclusions indicate that integrated assessment models tend to underestimate innovation on energy supply but overestimate the contributions by energy efficiency ( [[#IPCC--2018b|IPCC 2018b]] ). Scenarios emerging from cost-optimal climate-energy-economy models are too pessimistic, especially in the case of rapidly changing technologies such as wind and batteries in the past decade. Conversely, they tend to be too optimistic regarding the timing of action, or the availability of a given technology and its speed of diffusion ( [[#Shiraki--2020|Shiraki and Sugiyama 2020]] ). Furthermore, some technological and economic transformations may emerge as technically feasible from IAMs, but are not realistic if taking into account political economy, international politics, human behaviours, and cultural factors ( [[#Bosetti--2021|Bosetti 2021]] ).

There is a range of projected energy technology supply costs included in the IPCC’s Sixth Assessment Report (AR6) Scenario Database (Box 16.1). Variations of costs over time and across scenarios are within ranges comparable to those observed in recent years. Conversely, model results show that limiting warming to 2°C or 1.5°C will require faster diffusion of installed capacity of low-carbon energy options and a rapid phase-out of fossil-based options. This points to the importance of focusing on overcoming real-life barriers to technology deployment.

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