Essential Components of Energy and Climate Scenarios
Energy and climate models give insight into how the future may unfold, based on various technical, economic, societal, and policy assumptions. They are generally built as integrated assessment models (IAMs), which bring together simplified versions of the energy, economy, and climate systems. They are the main tool used by academic research groups, intergovernmental organizations, and policy-makers to understand how different energy and technology choices affect our ability to achieve climate goals and impact other elements of the energy transition.
For climate and energy models to provide robust and credible pathways to 1.5°C, they must consider several key elements. Accordingly, the CER should ensure its new scenarios include the criteria below to deliver on its mandate.
Disclose Consistently on All Types of Greenhouse Gas Emissions
Consistent, clear, and accurate reporting of all GHGs is essential for a comprehensive understanding of how to limit warming to 1.5°C. While carbon dioxide emissions from burning fossil fuels are the main cause of global warming, other shorter-lived climate pollutants such as methane, nitrous oxide, and fluorinated gases have higher warming potential. The relative contribution of these GHGs to global temperature rise must be carefully modelled to design effective short- and long-term mitigation strategies.
The Canadian Net-Zero Emissions Accountability Act enshrines in legislation Canada’s commitment to achieve net-zero GHG emissions by 2050. Hence, accounting for all GHG emissions will not only be important to assess the global impact on Canadian emissions for the global climate target but also to plan policies to achieve Canada’s own domestic emissions reduction target.
Report Transparently on Emissions Reductions Versus Carbon Dioxide Sequestration
Knowing the relative contribution of emissions reduction versus carbon dioxide removal (CDR) and offsets is essential to assess whether a climate model can realistically reach its target. The Intergovernmental Panel on Climate Change (IPCC) Special Report on 1.5°C explicitly warned that “CDR deployed at scale is unproven, and reliance on [CDR] is a major risk in the ability to limit warming to 1.5°C.” The assumptions a model makes about CDR as well as the expected reductions from carbon capture and storage (CCS) in the fossil fuel sector (fossil-CCS) have a major impact on the relative mitigation efforts required to limit temperature rise to 1.5°C. Credible and feasible assumptions about the use of CDR and CCS are especially critical to reliably estimating the rate at which oil and gas must be phased out. Moreover, relying on forest carbon offsets is also problematic: well-documented issues over additionality, performance, double counting, and leakage generally prevent accurate assessments of these offsets’ sequestration potential.
Considering these technologies’ risks, high costs, and limited mitigation potential, the CER should limit the reliance of their 1.5°C scenarios on fossil-CCS and CDR to the IPCC feasibility and sustainability thresholds to remain realistically implementable. Rapid and deep GHG emission reductions are essential in all credible 1.5°C scenarios. While CCS technologies are a crucial component of all climate models, their deployment is slow and has limited scale, and application should be restricted mainly to hard-to-abate sectors, such as cement and steel. To assess the sensitivity of their mitigation pathways to these assumptions, the CER should also create one scenario with zero CDR and CCS.
Include Granular Sectoral Emissions Reduction Pathways
Limiting warming to 1.5°C will require different emissions reduction solutions in each sector, which will necessarily occur at different paces. However, immutable constraints on the 1.5°C carbon budget—the maximum amount of CO2 that can be emitted over a period of time to limit global temperature to 1.5°C—mean that slower mitigation efforts in one sector will need to be compensated for by faster reductions in other sectors. In other words, giving one sector a bigger carbon budget leaves a smaller carbon budget for other sectors. Hence, governments need sector-level data to rationally distribute effort across sectors and track overall progress toward the Paris Agreement goal.
Accordingly, CER scenarios should feature sectoral mitigation pathways to provide useful guidance for Canadian policy-makers, energy producers, providers, and financial actors. Not only does the CER scenario need to show the trajectory of emissions reductions in each sector, it should also describe how electricity generation will be ramped up to accommodate the necessary declines in fossil fuel use in other sectors, such as transportation and buildings.
Integrate Equity Considerations
Modelling assumptions must also reflect a fair distribution of mitigation efforts across countries in line with the United Nations Framework Convention on Climate Change's principle of Common but Differentiated Responsibilities and Respective Capabilities. While most IAMs are based on least-cost assumptions—allocating a large share of mitigation efforts where they are the cheapest—this tends to put a higher burden on developing countries. Equitable and fair pathways must consider that fossil fuel production from large historical emitters with highly diversified economies, relatively low dependence on fossil fuel production, and high GDP per capita need to cut their emissions faster than the global baseline.
Canada, together with Australia, the United Kingdom, the United States, and Norway, belongs to this category of countries and has a responsibility and the capability to mitigate its emissions faster than the average emissions reduction trajectories in global 1.5°C scenarios. Moreover, global oil and gas production needs to decline rapidly by 2030 to allow emerging economies adequate time to phase out their coal dependence while meeting their social and economic goals.