Planning for net-zero GHG emissions by 2050: Moving from technical feasibility assessments to actionable analysis
Creators: Sperry, Luke H
Publisher: name: University of Alberta Library
Year: 2023

<p>Researchers with the Intergovernmental Panel on Climate Change (IPCC) predict that the net flux of anthropogenic greenhouse gas (GHG) emissions must reach zero by 2050 to limit global warming to 1.5°C within this century. This target requires that all GHG emissions resulting from human activity are offset by equal levels of natural or technological carbon uptake, meaning that action towards net-zero GHG emissions may involve measures aiming to minimize GHG sources or maximize GHG sinks. Achieving net-zero greenhouse gas (GHG) emissions may only be possible through the rapid deployment of new technologies at an unprecedented rate, requiring policymakers to develop creative policy instruments to facilitate collaborative action across sector boundaries. This research describes a novel approach to planning for and assessing action towards net-zero GHG emissions based on bottom-up, accounting-based energy modelling techniques.The first part of this research develops a framework for assessing the contribution potential of energy-efficiency measures towards economy-wide net-zero emission targets. The framework uses a bottom-up energy model spanning the agriculture, cement, chemicals, commercial and institutional, iron and steel, oil extraction, petroleum refining, and residential sectors, together accounting for over 75% of annual energy demand in the case study region of Alberta, Canada. 81 energy-efficiency improvements were identified for these sectors which, by 2050, may mitigate 8% of regional annual GHG emissions relative to a baseline in which shares and efficiencies of existing technologies are held constant. Considering the interaction effects between simultaneously applied measures, measures representing 80% of the identified cumulative mitigation potential may be implemented at negative cost. The assessed energy-efficiency measures represent cost-effective and readily deployable GHG mitigation strategies for most major economic sectors, but together only account for a small fraction of the GHG mitigation required for complete energy system decarbonization in the assessed region. This framework offers value to policymakers developing actionable policy and milestone targets towards long-term emissions-reduction goals.This framework was expanded to assess technology-specific measures toward achieving net-zero GHG emissions within a multi-regional multi-sectoral economy, where the effects, costs, and benefits of various GHG mitigation measures could be assessed incrementally. A portfolio of 184 measures was developed. Measures were categorized according to practical type and technological readiness  and their maximum technical GHG mitigation potential was evaluated. These measures are applicable in the cement, chemicals, commercial and institutional, iron and steel, oil sands, petroleum refining, pulp and paper, residential, and transportation sectors. The effects of these measures were compared to a static reference scenario and a business-as-usual scenario reflecting current policy. Together, the assessed measures represent an extensive portfolio of commercially available opportunities for energy efficiency improvement, fuel switching, and carbon capture and storage. Under current policy, these measures may mitigate 33% of baseline GHG emissions by 2050 and represent significant economic cost savings. If implemented to their maximum extent, they may reduce baseline GHG emissions by 50% by 2050 at additional economic costs. The results indicate that there is a clear gap between national GHG reduction ambitions and available solutions and highlight the need for more transparent and specific energy systems models for decarbonization assessment.This research ultimately highlights the gap between currently available GHG reduction measures and complete decarbonization; achieving net-zero GHG emissions will only be possible through a complete transformation of entire energy systems and economies. Existing assessment frameworks that represent net-zero as a system-wide constraint and model hypothetical technologies alongside proven measures often fail to communicate the magnitude of change implied by this target. </p>