11.6 Takeaways


As the review of these reports makes clear, the complexity of energy systems and other sources of emissions in various regions of the world can make broad-brush comparisons either difficult or, even worse, misleading. Nonetheless, a synthesis of the comparisons made in this chapter helps highlight a few important points in reflections on how to achieve net-zero in advanced economies. 

The first is that regardless of the role that hydrogen may end up playing once uncertainties are reduced and infrastructure choices are made, low-carbon electricity demand will grow significantly and fast. While the specifics vary, all regions covered in these reports underscore the key challenges of increasing grid infrastructure capacity to accommodate drastically higher demand (especially peak), despite the efficiency gains of electrification, of managing high shares of variable generation, and of determining the exact role of baseload (nuclear or hydroelectric) and storage in this mix.A second point is that all reports include a discussion of sectors where many uncertainties remain about the infrastructure development that should be favoured, depending on which, if any, of the many currently emerging or marginal technologies will end up dominating the sector. Results for industry (outside of energy production) and freight and aviation transport in particular show not only that decarbonization is particularly costly with current technologies for these sectors, but also that many options exist that may or may not develop rapidly through technological innovation—to say nothing of developments that are impossible to foresee at this time. In any case, one overarching implication is that while governments need not choose every specific technology to favour, they must nevertheless make early decisions on which infrastructure to help develop in a way that enables some flexibility to account for future innovations. 

The third point is that all five reports agree on the unavoidable role of CCS and BECCS in reaching net-zero emissions with current technologies, given the remaining emissions from the various sectors, especially agriculture, industrial processes, transport and waste. Most reports explicitly or implicitly follow a line of discussion similar to Chapters 9 and 12 of this Outlook−that is, that given the magnitude of the remaining emissions in net-zero scenarios, carbon capture and negative emissions should be kept only to compensate for unavoidable emissions, which is to say that priority should always be given to mitigation. This point can be extended to the discussion of the role of DAC, which is minor in all reports but the US, especially in scenarios where biomass is more constrained. 

Finally, informative comparisons like those attempted here need not be limited to the points covered in the CEO2021. For instance, an area neglected in this Outlook is the importance of behavioural changes, notably dietary preferences, to which FR and the UK accord special attention. Perhaps more importantly, while LULUCF is not discussed in the CEO2021 and in most of the other four reports, FR pays special attention to the management of forests and land, including through agricultural policies. This is certainly an area to delve into more deeply for other regions as well, including Canada.