Have climate policies accelerated energy transitions? Historical evolution of electricity mix in the G7 and the EU compared to net-zero targets

M. Suzuki, J. Jewell & A. Cherp. (2023). Have climate policies accelerated energy transitions? Historical evolution of electricity mix in the G7 and the EU compared to net-zero targets. Energy Research & Social Science 106, 103281. Open Access. DOI: https://doi.org/10.1016/j.erss.2023.103281

Climate policies are often assumed to have significant impacts on the nature and speed of energy transitions. To investigate this hypothesis, we develop an approach to categorise, trace, and compare energy transitions across countries and time periods. We apply this approach to analyse electricity transitions in the G7 and the EU between 1960 and 2022, specifically examining whether and how climate policies altered the transitions beyond historical trends. Additionally, we conduct a feasibility analysis of the required transition in these countries by 2035 to keep the global temperature increase below 1.5°C. We find that climate policies have so far had limited impacts: while they may have influenced the choice of deployed technologies and the type of transitions, they have not accelerated the growth of low-carbon technologies or hastened the decline of fossil fuels. Instead, electricity transitions in the G7 and the EU have strongly correlated with the changes in electricity demand throughout the last six decades. In contrast, meeting the 1.5°C target requires unprecedented supply-centred transitions by 2035 where all G7 countries and the EU must expand low-carbon electricity five times faster and reduce fossil fuels two times faster on average compared to the rates in 2015–2020. This highlights the insufficiency of incremental changes and the need for a radically stronger effort to meet the climate target.

Historical diffusion of nuclear, wind and solar power in different national contexts: implications for climate mitigation pathways

V. Vinichenko, J. Jewell, J. Jacobsson, A. Cherp. (2023). Historical diffusion of nuclear, wind and solar power in different national contexts: implications for climate mitigation pathways. Environmental Research Letters 18, 094066. Open Access. DOI: https://doi.org/10.1088/1748-9326/acf47a

Climate change mitigation requires rapid expansion of low-carbon electricity but there is a disagreement on whether available technologies such as renewables and nuclear power can be scaled up sufficiently fast. Here we analyze the diffusion of nuclear (from the 1960s), as well as wind and solar (from the 1980–90s) power. We show that all these technologies have been adopted in most large economies except major energy exporters, but solar and wind have diffused across countries faster and wider than nuclear. After the initial adoption, the maximum annual growth for nuclear power has been 2.6% of national electricity supply (IQR 1.3%–6%), for wind − 1.1% (0.6%–1.7%), and for solar − 0.8% (0.5%–1.3%). The fastest growth of nuclear power occurred in Western Europe in the 1980s, a response by industrialized democracies to the energy supply crises of the 1970s. The European Union (EU), currently experiencing a similar energy supply shock, is planning to expand wind and solar at similarly fast rates. This illustrates that national contexts can impact the speed of technology diffusion at least as much as technology characteristics like cost, granularity, and complexity. In the Intergovernmental Panel on Climate Change mitigation pathways, renewables grow much faster than nuclear due to their lower projected costs, though empirical evidence does not show that the cost is the sole factor determining the speed of diffusion. We demonstrate that expanding low-carbon electricity in Asia in line with the 1.5 °C target requires growth of nuclear power even if renewables increase as fast as in the most ambitious EU's plans. 2 °C-consistent pathways in Asia are compatible with replicating China's nuclear power plans in the whole region, while simultaneously expanding renewables as fast as in the near-term projections for the EU. Our analysis demonstrates the usefulness of empirically-benchmarked feasibility spaces for future technology projections.

The feasibility of climate action: Bridging the inside and the outside view through feasibility spaces

J. Jewell & A. Cherp. (2023). The feasibility of climate action: Bridging the inside and the outside view through feasibility spaces. WIREs Climate Change. DOI: https://doi.org/https://doi.org/10.1002/wcc.838

The feasibility of different options to reduce the risks of climate change has engaged scholars for decades. Yet there is no agreement on how to define and assess feasibility. We define feasible as “do-able under realistic assumptions.” A sound feasibility assessment is based on causal reasoning; enables comparison of feasibility across climate options, contexts, and implementation levels; and reflexively considers the agency of its audience. Global climate scenarios are a good starting point for assessing the feasibility of climate options since they represent causal pathways, quantify implementation levels, and consider policy choices. Yet, scenario developers face difficulties to represent all relevant causalities, assess the realism of assumptions, assign likelihood to potential outcomes, and evaluate the agency of their users, which calls for external feasibility assessments. Existing approaches to feasibility assessment mirror the “inside” and the “outside” view coined by Kahneman and co-authors. The inside view considers climate change as a unique challenge and seeks to identify barriers that should be overcome by political choice, commitment, and skill. The outside view assesses feasibility through examining historical analogies (reference cases) to the given climate option. Recent studies seek to bridge the inside and the outside views through “feasibility spaces,” by identifying reference cases for a climate option, measuring their outcomes and relevant characteristics, and mapping them together with the expected outcomes and characteristics of the climate option. Feasibility spaces are a promising method to prioritize climate options, realistically assess the achievability of climate goals, and construct scenarios with empirically-grounded assumptions.

Feasibility trade-offs in decarbonisation of power sector with high coal dependence: A case of Korea

M. Hyun, A. Cherp, J. Jewell, Y. J. Kim & J. Eom. (2023). Feasibility trade-offs in decarbonisation of power sector with high coal dependence: A case of Korea. Renewable and Sustainable Energy Transition, 3, 100050. Open Access. DOI: https://doi.org/10.1016/j.rset.2023.100050

Decarbonising the power sector requires feasible strategies for the rapid phase-out of fossil fuels and the expansion of low-carbon sources. This study assesses the feasibility of plausible decarbonisation scenarios for the power sector in the Republic of Korea through 2050 and 2060. Our power plant stock accounting model results show that achieving zero emissions from the power sector by the mid-century requires either an ambitious expansion of renewables backed by gas-fired generation equipped with carbon capture and storage or a significant increase of nuclear power. The first strategy implies replicating and maintaining for decades the maximum growth rates of solar power achieved in leading countries and becoming an early and ambitious adopter of the carbon capture and storage technology. The alternative expansion of nuclear power has historical precedents in Korea and other countries but may not be acceptable in the current political and regulatory environment. Hence, our analysis shows that the potential hurdles for decarbonisation in the power sector in Korea are formidable but manageable and should be overcome over the coming years, which gives hope to other similar countries.

Phasing out coal for 2 °C target requires worldwide replication of most ambitious national plans despite security and fairness concerns

V. Vinichenko, M. Vetier, J. Jewell, L. Nacke  & A. Cherp.  (2023). Phasing out coal for 2 °C target requires worldwide replication of most ambitious national plans despite security and fairness concerns. Environmental Research Letters 18, 014031. Open Access. DOI: https://doi.org/10.1088/1748-9326/acadf6

Ending the use of unabated coal power is a key climate change mitigation measure. However, we do not know how fast it is feasible to phase-out coal on the global scale. Historical experience of individual countries indicates feasible coal phase-out rates, but can these be upscaled to the global level and accelerated by deliberate action? To answer this question, we analyse 72 national coal power phase-out pledges and show that these pledges have diffused to more challenging socio-economic contexts and now cover 17% of the global coal power fleet, but their impact on emissions (up to 4.8 Gt CO2 avoided by 2050) remains small compared to what is needed for achieving Paris climate targets. We also show that the ambition of pledges is similar across countries and broadly in line with historical precedents of coal power decline. While some pledges strengthen over time, up to 10% have been weakened by the energy crisis caused by the Russo-Ukrainian war. We construct scenarios of coal power decline based on empirically-grounded assumptions about future diffusion and ambition of coal phase-out policies. We show that under these assumptions unabated coal power generation in 2022–2050 would be between the median generation in 2 °C-consistent IPCC AR6 pathways and the third quartile in 2.5 °C-consistent pathways. More ambitious coal phase-out scenarios require much stronger effort in Asia than in OECD countries, which raises fairness and equity concerns. The majority of the 1.5 °C- and 2 °C-consistent IPCC pathways envision even more unequal distribution of effort and faster coal power decline in India and China than has ever been historically observed in individual countries or pledged by climate leaders.

National growth dynamics of wind and solar power compared to the growth required for global climate targets

A. Cherp, V. Vinichenko, J. Tosun, J. Gordon & J. Jewell. (2021). National growth dynamics of wind and solar power compared to the growth required for global climate targets. Nature Energy 6, 742–754. Gated. DOI: https://doi.org/10.1038/s41560-021-00863-0. Free SharedIt link (view only) code on GitHub: https://github.com/poletresearch/RES_article

Climate mitigation scenarios envision considerable growth of wind and solar power, but scholars disagree on how this growth compares with historical trends. Here we fit growth models to wind and solar trajectories to identify countries in which growth has already stabilized after the initial acceleration. National growth has followed S-curves to reach maximum annual rates of 0.8% (interquartile range of 0.6–1.1%) of the total electricity supply for onshore wind and 0.6% (0.4–0.9%) for solar. In comparison, one-half of 1.5 °C-compatible scenarios envision global growth of wind power above 1.3% and of solar power above 1.4%, while one-quarter of these scenarios envision global growth of solar above 3.3% per year. Replicating or exceeding the fastest national growth globally may be challenging because, so far, countries that introduced wind and solar power later have not achieved higher maximum growth rates, despite their generally speedier progression through the technology adoption cycle.