Search Results
Taxing interacting externalities of ocean acidification, global warming, and eutrophication
2021, Hänsel, Martin C., Bergh, Jeroen C. J. M. van den
We model a stylized economy dependent on agriculture and fisheries to study optimal environmental policy in the face of interacting external effects of ocean acidification, global warming, and eutrophication. This allows us to capture some of the latest insights from research on ocean acidification. Using a static two-sector general equilibrium model we derive optimal rules for national taxes on (Formula presented.) emissions and agricultural run-off and show how they depend on both isolated and interacting damage effects. In addition, we derive a second-best rule for a tax on agricultural run-off of fertilizers for the realistic case that effective internalization of (Formula presented.) externalities is lacking. The results contribute to a better understanding of the social costs of ocean acidification in coastal economies when there is interaction with other environmental stressors. Recommendations for Resource Managers: Marginal environmental damages from (Formula presented.) emissions should be internalized by a tax on (Formula presented.) emissions that is high enough to not only reflect marginal damages from temperature increases, but also marginal damages from ocean acidification and the interaction of both with regional sources of acidification like nutrient run-off from agriculture. In the absence of serious national policies that fully internalize externalities, a sufficiently high tax on regional nutrient run-off of fertilizers used in agricultural production can limit not only marginal environmental damages from nutrient run-off but also account for unregulated carbon emissions. Putting such regional policies in place that consider multiple important drivers of environmental change will be of particular importance for developing coastal economies that are likely to suffer the most from ocean acidification. © 2021 The Authors. Natural Resource Modeling published by Wiley Periodicals LLC.
Grounding Social Foundations for Integrated Assessment Models of Climate Change
2020, Mathias, Jean‐Denis, Debeljak, Marko, Deffuant, Guillaume, Diemer, Arnaud, Dierickx, Florian, Donges, Jonathan F., Gladkykh, Ganna, Heitzig, Jobst, Holtz, Georg, Obergassel, Wolfgang, Pellaud, Francine, Sánchez, Angel, Trajanov, Aneta, Videira, Nuno
Integrated assessment models (IAMs) are commonly used by decision makers in order to derive climate policies. IAMs are currently based on climate-economics interactions, whereas the role of social system has been highlighted to be of prime importance on the implementation of climate policies. Beyond existing IAMs, we argue that it is therefore urgent to increase efforts in the integration of social processes within IAMs. For achieving such a challenge, we present some promising avenues of research based on the social branches of economics. We finally present the potential implications yielded by such social IAMs. ©2020. The Authors. Earth's Future published by Wiley Periodicals LLC on behalf of American Geophysical Union
Exploring Global Climate Policy Futures and Their Representation in Integrated Assessment Models
2022, Hickmann, Thomas, Bertram, Christoph, Biermann, Frank, Brutschin, Elina, Kriegler, Elmar, Livingston, Jasmine E., Pianta, Silvia, Riahi, Keywan, van Ruijven, Bas, van Vuuren, Detlef
The Paris Agreement, adopted in 2015, paved the way for a new hybrid global climate governance architecture with both bottom‐up and top‐down elements. While governments can choose individual climate goals and actions, a global stocktake and a ratcheting‐up mechanism have been put in place with the overall aim to ensure that collective efforts will prevent increasing adverse impacts of climate change. Integrated assessment models show that current combined climate commitments and policies of national governments fall short of keeping global warming to 1.5 °C or 2 °C above preindustrial levels. Although major greenhouse gas emitters, such as China, the European Union, India, the United States under the Biden administration, and several other countries, have made new pledges to take more ambitious climate action, it is highly uncertain where global climate policy is heading. Scenarios in line with long‐term temperature targets typically assume a simplistic and hardly realistic level of harmonization of climate policies across countries. Against this backdrop, this article develops four archetypes for the further evolution of the global climate governance architecture and matches them with existing sets of scenarios developed by integrated assessment models. By these means, the article identifies knowledge gaps in the current scenario literature and discusses possible research avenues to explore the pre‐conditions for successful coordination of national policies towards achieving the long‐term target stipulated in the Paris Agreement.
Early retirement of power plants in climate mitigation scenarios
2020, Fofrich, Robert, Tong, Dan, Calvin, Katherine, De Boer, Harmen Sytze, Emmerling, Johannes, Fricko, Oliver, Fujimori, Shinichiro, Luderer, Gunnar, Rogelj, Joeri, Davis, Steven J.
International efforts to avoid dangerous climate change aim for large and rapid reductions of fossil fuel CO2 emissions worldwide, including nearly complete decarbonization of the electric power sector. However, achieving such rapid reductions may depend on early retirement of coal- and natural gas-fired power plants. Here, we analyze future fossil fuel electricity demand in 171 energy-emissions scenarios from Integrated Assessment Models (IAMs), evaluating the implicit retirements and/or reduced operation of generating infrastructure. Although IAMs calculate retirements endogenously, the structure and methods of each model differ; we use a standard approach to infer retirements in outputs from all six major IAMs and—unlike the IAMs themselves—we begin with the age distribution and region-specific operating capacities of the existing power fleet. We find that coal-fired power plants in scenarios consistent with international climate targets (i.e. keeping global warming well-below 2 °C or 1.5 °C) retire one to three decades earlier than historically has been the case. If plants are built to meet projected fossil electricity demand and instead allowed to operate at the level and over the lifetimes they have historically, the roughly 200 Gt CO2 of additional emissions this century would be incompatible with keeping global warming well-below 2 °C. Thus, ambitious climate mitigation scenarios entail drastic, and perhaps un-appreciated, changes in the operating and/or retirement schedules of power infrastructure.
Energy system developments and investments in the decisive decade for the Paris Agreement goals
2021-6-29, Bertram, Christoph, Riahi, Keywan, Hilaire, Jérôme, Bosetti, Valentina, Drouet, Laurent, Fricko, Oliver, Malik, Aman, Pupo Nogueira, Larissa, van der Zwaan, Bob, van Ruijven, Bas, van Vuuren, Detlef, Weitzel, Matthias, Dalla Longa, Francesco, de Boer, Harmen-Sytze, Emmerling, Johannes, Fosse, Florian, Fragkiadakis, Kostas, Harmsen, Mathijs, Keramidas, Kimon, Kishimoto, Paul Natsuo, Kriegler, Elmar, Krey, Volker, Paroussos, Leonidas, Saygin, Deger, Vrontisi, Zoi, Luderer, Gunnar
The Paris Agreement does not only stipulate to limit the global average temperature increase to well below 2 °C, it also calls for 'making finance flows consistent with a pathway towards low greenhouse gas emissions'. Consequently, there is an urgent need to understand the implications of climate targets for energy systems and quantify the associated investment requirements in the coming decade. A meaningful analysis must however consider the near-term mitigation requirements to avoid the overshoot of a temperature goal. It must also include the recently observed fast technological progress in key mitigation options. Here, we use a new and unique scenario ensemble that limit peak warming by construction and that stems from seven up-to-date integrated assessment models. This allows us to study the near-term implications of different limits to peak temperature increase under a consistent and up-to-date set of assumptions. We find that ambitious immediate action allows for limiting median warming outcomes to well below 2 °C in all models. By contrast, current nationally determined contributions for 2030 would add around 0.2 °C of peak warming, leading to an unavoidable transgression of 1.5 °C in all models, and 2 °C in some. In contrast to the incremental changes as foreseen by current plans, ambitious peak warming targets require decisive emission cuts until 2030, with the most substantial contribution to decarbonization coming from the power sector. Therefore, investments into low-carbon power generation need to increase beyond current levels to meet the Paris goals, especially for solar and wind technologies and related system enhancements for electricity transmission, distribution and storage. Estimates on absolute investment levels, up-scaling of other low-carbon power generation technologies and investment shares in less ambitious scenarios vary considerably across models. In scenarios limiting peak warming to below 2 °C, while coal is phased out quickly, oil and gas are still being used significantly until 2030, albeit at lower than current levels. This requires continued investments into existing oil and gas infrastructure, but investments into new fields in such scenarios might not be needed. The results show that credible and effective policy action is essential for ensuring efficient allocation of investments aligned with medium-term climate targets.
What are the social outcomes of climate policies? A systematic map and review of the ex-post literature
2020, Lamb, William F., Antal, Miklós, Bohnenberger, Katharina, Brand-Correa, Lina I., Müller-Hansen, Finn, Jakob, Michael, Minx, Jan C., Raiser, Kilian, Williams, Laurence, Sovacool, Benjamin K.
It is critical to ensure climate and energy policies are just, equitable and beneficial for communities, both to sustain public support for decarbonisation and address multifaceted societal challenges. Our objective in this article is to examine the diverse social outcomes that have resulted from climate policies, in varying contexts worldwide, over the past few decades. We review 203 ex-post climate policy assessments that analyse social outcomes in the literature. We systematically and comprehensively map out this work, identifying articles on carbon, energy and transport taxes, feed-in-tariffs, subsidies, direct procurement policies, large renewable deployment projects, and other regulatory and market-based interventions. We code each article in terms of their studied social outcomes and effects, with a focus on electricity access, energy affordability, community cohesion, employment, distributional and equity issues, livelihoods and poverty, procedural justice, subjective well-being and drudgery. Our analysis finds that climate and energy policies often fall short of delivering positive social outcomes. Nonetheless, across country contexts and policy types there are manifold examples of climate policymaking that does deliver on both social and climate goals. This requires attending to distributive and procedural justice in policy design, and making use of appropriate mechanisms to ensure that policy costs and benefits are fairly shared. We emphasize the need to further advance ex-post policy assessments and learn about what policies work for a just transition.
Ten new insights in climate science 2020 – a horizon scan
2021, Pihl, Erik, Alfredsson, Eva, Bengtsson, Magnus, Bowen, Kathryn J., Cástan Broto, Vanesa, Chou, Kuei Tien, Cleugh, Helen, Ebi, Kristie, Edwards, Clea M., Fisher, Eleanor, Friedlingstein, Pierre, Godoy-Faúndez, Alex, Gupta, Mukesh, Harrington, Alexandra R., Hayes, Katie, Hayward, Bronwyn M., Hebden, Sophie R., Hickmann, Thomas, Hugelius, Gustaf, Ilyina, Tatiana, Jackson, Robert B., Keenan, Trevor F., Lambino, Ria A., Leuzinger, Sebastian, Malmaeus, Mikael, McDonald, Robert I., McMichael, Celia, Miller, Clark A., Muratori, Matteo, Nagabhatla, Nidhi, Nagendra, Harini, Passarello, Cristian, Penuelas, Josep, Pongratz, Julia, Rockström, Johan, Romero-Lankao, Patricia, Roy, Joyashree, Scaife, Adam A., Schlosser, Peter, Schuur, Edward, Scobie, Michelle, Sherwood, Steven C., Sioen, Giles B., Skovgaard, Jakob, Sobenes Obregon, Edgardo A., Sonntag, Sebastian, Spangenberg, Joachim H., Spijkers, Otto, Srivastava, Leena, Stammer, Detlef B., Torres, Pedro H. C., Turetsky, Merritt R., Ukkola, Anna M., van Vuuren, Detlef P., Voigt, Christina, Wannous, Chadia, Zelinka, Mark D.
Non-technical summary: We summarize some of the past year's most important findings within climate change-related research. New research has improved our understanding of Earth's sensitivity to carbon dioxide, finds that permafrost thaw could release more carbon emissions than expected and that the uptake of carbon in tropical ecosystems is weakening. Adverse impacts on human society include increasing water shortages and impacts on mental health. Options for solutions emerge from rethinking economic models, rights-based litigation, strengthened governance systems and a new social contract. The disruption caused by COVID-19 could be seized as an opportunity for positive change, directing economic stimulus towards sustainable investments. Technical summary: A synthesis is made of ten fields within climate science where there have been significant advances since mid-2019, through an expert elicitation process with broad disciplinary scope. Findings include: (1) a better understanding of equilibrium climate sensitivity; (2) abrupt thaw as an accelerator of carbon release from permafrost; (3) changes to global and regional land carbon sinks; (4) impacts of climate change on water crises, including equity perspectives; (5) adverse effects on mental health from climate change; (6) immediate effects on climate of the COVID-19 pandemic and requirements for recovery packages to deliver on the Paris Agreement; (7) suggested long-term changes to governance and a social contract to address climate change, learning from the current pandemic, (8) updated positive cost-benefit ratio and new perspectives on the potential for green growth in the short- A nd long-term perspective; (9) urban electrification as a strategy to move towards low-carbon energy systems and (10) rights-based litigation as an increasingly important method to address climate change, with recent clarifications on the legal standing and representation of future generations. Social media summary: Stronger permafrost thaw, COVID-19 effects and growing mental health impacts among highlights of latest climate science. Copyright © The Author(s), 2021. Published by Cambridge University Press.