Pandemic politics—lessons for solar geoengineering

Responses to the COVID-19 emergency have exposed break-points at the interface of science, media, and policy. We summarize five lessons that should be heeded if climate change ever enters a state of emergency perceived to warrant stratospheric aerosol injection

Modelling net-zero emissions energy systems requires a change in approach

Energy modelling can assist national decision makers in determining strategies that achieve net-zero greenhouse gas (GHG) emissions. However, three key challenges for the modelling community are emerging under this radical climate target that needs to be recognized and addressed. A first challenge is the need to represent new mitigation options not currently represented in many energy models. We emphasize here the under representation of end-use sector demand-side options due to the traditional supply side focus of many energy models, along with issues surrounding robustness in deploying carbon dioxide removal (CDR) options. A second challenge concerns the types of models used. We highlight doubts about whether current models provide sufficient relevant insights on system feasibility, actor behaviour, and policy effectiveness. A third challenge concerns how models are applied for policy analyses. Priorities include the need for expanding scenario thinking to incorporate a wider range of uncertainty factors, providing insights on target setting, alignment with broader policy objectives, and improving engagement and transparency of approaches. There is a significant risk that without reconsidering energy modelling approaches, the role that the modelling community can play in providing effective decision support may be reduced. Such support is critical, as countries seek to develop new Nationally Determined Contributions and longer-term strategies over the next few years

Modelling net-zero emissions energy systems requires a change in approach

Energy modelling can assist national decision makers in determining strategies that achieve net-zero greenhouse gas (GHG) emissions. However, three key challenges for the modelling community are emerging under this radical climate target that needs to be recognized and addressed. A first challenge is the need to represent new mitigation options not currently represented in many energy models. We emphasize here the under representation of end-use sector demand-side options due to the traditional supply side focus of many energy models, along with issues surrounding robustness in deploying carbon dioxide removal (CDR) options. A second challenge concerns the types of models used. We highlight doubts about whether current models provide sufficient relevant insights on system feasibility, actor behaviour, and policy effectiveness. A third challenge concerns how models are applied for policy analyses. Priorities include the need for expanding scenario thinking to incorporate a wider range of uncertainty factors, providing insights on target setting, alignment with broader policy objectives, and improving engagement and transparency of approaches. There is a significant risk that without reconsidering energy modelling approaches, the role that the modelling community can play in providing effective decision support may be reduced. Such support is critical, as countries seek to develop new Nationally Determined Contributions and longer-term strategies over the next few years

Targeting carbon dioxide removal in the European Union

In principle, many climate policymakers have accepted that large-scale carbon dioxide removal (CDR) is necessary to meet the Paris Agreement’s mitigation targets, but they have avoided proposing by whom CDR might be delivered. Given its role in international climate policy, the European Union (EU) might be expected to lead the way. But among EU climate policymakers so far there is little talk on CDR, let alone action. Here we assess how best to ‘target’ CDR to motivate EU policymakers exploring which CDR target strategy may work best to start dealing with CDR on a meaningful scale. A comprehensive CDR approach would focus on delivering the CDR volumes required from the EU by 2100, approximately at least 50 Gigatonnes (Gt) CO2, according to global model simulations aiming to keep warming below 2°C. A limited CDR approach would focus on an intermediate target to deliver the CDR needed to reach ‘net zero emissions’ (i.e. the gross negative emissions needed to offset residual positive emissions that are too expensive or even impossible to mitigate). We argue that a comprehensive CDR approach may be too intimidating for EU policymakers. A limited CDR approach that only addresses the necessary steps to reach the (intermediate) target of ‘net zero emissions’ is arguably more achievable, since it is a better match to the existing policy paradigm and would allow for a pragmatic phase-in of CDR while avoiding outright resistance by environmental NGOs and the broader public. Key policy insights Making CDR an integral part of EU climate policy has the potential to significantly reshape the policy landscape. Burden sharing considerations would probably play a major role, with comprehensive CDR prolonging the disparity and tensions between progressives and laggards. Introducing limited CDR in the context of ‘net zero’ pathways would retain a visible primary focus on decarbonization but acknowledge the need for a significant enhancement of removals via ‘natural’ and/or ‘engineered’ sinks. A decarbonization approach that intends to lead to a low level of ‘residual emissions’ (to be tackled by a pragmatic phase-in of CDR) should be the priority of EU climate policy. © 2018, © 2018 The Author(s). Published by Informa UK Limited, trading as Taylor Francis Group

Taking stock of carbon dioxide removal policy in emerging economies: developments in Brazil, China, and India

Deliberately removing carbon dioxide from the atmosphere is an important element of bringing mitigation pathways in line with the climate goals of the Paris Agreement. To reach global net-zero CO2 emissions and limit global warming to 1.5°C with no or limited overshoot, global mitigation pathways assessed by IPCC’s Sixth Assessment Report require some world regions to achieve net-negative CO2 emissions with large-scale carbon dioxide removal (CDR) deployment. This raises important questions about the availability and feasibility of CDR deployment in different societal and political contexts. This paper therefore combines an analysis of CDR deployment in a sample of scenarios from the IPCC AR6 database with a bottom-up analysis of the state of CDR governance and policy in countries considered key in scaling up CDR capacity and not yet covered by existing research. In particular, the paper focuses on Brazil, China, and India as important emerging economies and large emitters. We highlight the expected use of CDR methods in those regions in scenarios and systematically assess and compare the level of CDR regulation and innovation across these countries. This comparative perspective has the potential to broaden the understanding of existing and emerging CDR policies and politics. The synthesis of the case studies provides three key contributions to existing literature: First, we explore the state of CDR governance and policymaking in key emerging economies. As in OECD countries, there is a notable lack of CDR regulation and innovation to enable the scale of CDR required in the short- and medium term. Second, we identify that repurposing policies is a key type of emerging CDR policymaking in these countries targeting CDR methods in the land use, land use change and forestry (LULUCF) sector. We find that the repurposing efforts strengthen the level of regulation and innovation for this group of methods. Third, we explore three building blocks (regional differentiation, delay of upscaling, sustainability thresholds) of plausible CDR deployment narratives that could help bridge integrated assessment models and comparative case studies in future research

Cross-sectoral perspectives (Chapter 12)

The total emission mitigation potential achievable by the year 2030, calculated based on sectoral assessments, is sufficient to reduce global greenhouse gas emissions to half of the current (2019) level or less (robust evidence, high agreement). This potential (32–44 GtCO2-eq) requires implementation of a wide range of mitigation options. Options with mitigation costs lower than USD20 tCO2 –1 make up more than half of this potential and are available for all sectors

Was sind negative Emissionen, und warum brauchen wir sie? Akademienprojekt ‘Energiesysteme der Zukunft’ (ESYS)

Selbst mit ambitionierteren Maßnahmen zur Vermeidung von Emissionen lässt sich Klimaneutralität und damit die Stabilisierung der Temperatur nicht mehr erreichen. Darauf weist der Weltklimarat in seinem sechsten Sachstandsbericht hin. Zusätzlich zu einer schnelleren Reduktion der Emissionen muss CO2 der Atmosphäre entzogen und anschließend eingelagert werden, um nicht vermeidbare Restemissionen auszugleichen, etwa aus der Landwirtschaft. Sogenannte „negative Emissionen“ können zum Beispiel durch Aufforstung erzeugt werden. Es gibt aber eine Reihe weiterer natürlicher und technischer Verfahren, den entnommenen Kohlenstoff dauerhaft einzulagern und aus der Atmosphäre fernzuhalten. In diesem „Kurz erklärt“ skizzieren Fachleute des Akademienprojekts ESYS den aktuellen Forschungsstand, erläutern Verfahren zur CO2-Entnahme und benennen deren jeweiligen Vor- und Nachteile