Summary of assessment results.

Despite rising climate urgency, decision-makers continue to support emission reduction options that appear promising on the face of it but hinder progress in practice. Whether through more efficient gasoline engines or waste heat recovery from fossil fuel combustion, many proposed solutions encourage partial emissions reductions without adequate consideration of whether they can build toward net zero systems of the future. As a result, it is essential that policy decisions are interrogated in terms of their alignment with net zero pathways (or lack thereof) and that decision-makers are both informed about and held to account for the compatibility of near-term choices with long-run system change. This study conceptualizes particularly problematic directions as ‘dead-end pathways’ and outlines a framework for identifying and avoiding them. The framework assesses pathways in relation to three dimensions: depth (how close they can come to virtually eliminating emissions in a stipulated system context), breadth (how widely they can be applied across the specified system), and timeliness (how rapidly they can be deployed). The study then applies this framework to three brief case studies drawn from road transportation, each of which fail on one of these dimensions.