Dissemination of CICERO researchers’ scientific publications, reports and other outputs.

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Nature Reviews Earth & Environment

Climate impacts of hydrogen emissions

Maria Sand et. al. including Ragnhild B. Skeie, Gunnar Myhre, Marit Sandstad and Srinath Krishnan from CICERO

Current estimates of hydrogen’s climate impact are now sufficiently robust to inform policy and business decision-making, according to researchers in a new review article on the climate impacts of hydrogen emissions.  Read the paper. Read the press release.

Publications

Environmental Research Letters

Permafrost carbon–climate feedback amplifies Earth system tipping risks

Norman E. Steinert et. al. includingMarit Sandstad and Benjamin Sanderson from CICERO

Global warming leads to widespread permafrost thaw and subsequent emissions of carbon dioxide and methane, driving the permafrost carbon–climate feedback which amplifies climate change. Many current-generation climate models omit this feedback, limiting projections of long-term temperature outcomes and associated Earth system tipping risks. This paper investigate how this feedback affects the risk and timing of crossing tipping points in the Earth system by integrating permafrost carbon emissions into temperature projections for idealized stabilization and overshoot scenarios. Read more.  

Journal of Common Market Studies

European Union Agencies and Implementation: ACER's Authority in Effectuating a Contested EU Energy Rule

Torbjørg Jevnakerand Per Ove Eikeland

EU agencies have increasingly been tasked with supporting the implementation of EU legislation, yet their impact on how such implementation unfolds remains understudied. This article examines how the work of an EU agency can shape the implementation of a specific EU rule. Focusing on the Agency for the Cooperation of Energy Regulators (ACER) and the 70% rule under EU electricity market regulation, we explore how ACER used its tasks to promote more uniform implementation across member states. Read more. 

Science  

Clouds moderate Amazon deforestation’s climate effects

Gunnar Myhre

Amazon deforestation does more than reduce carbon uptake; it also alters clouds. A new study by Dror and Feingold finds increased cloud cover following deforestation, which dampens the net climate effect. In this Perspective article, Gunnar Myhre discusses the implications of these findings and highlight the importance of long-term satellite records Read more. 

npj Natural Hazards

Rapid intensification of recent extreme precipitation events in southern Norway under warmer climate conditions

Iris Mužić, Øivind Hodnebrog, Gunnar Myhre, Jana Sillmann and Camilla W. Stjern

High sub-daily intensity of extreme precipitation events in southern Norway causes landslides, debris flows, and infrastructure damage, affecting safety. This paper quantifies changes in intensity and spatial extent of recent short-duration high-impact extreme precipitation events in southern Norway, "Gyda" (January 2022), "Hans" (August 2023), and "Bø" (July 2024) under past colder (-2 °C) and future warmer (+2 °C and +4 °C) climate. Read more. 

Ecological Economics

Is tax aversion dominant? A survey experiment on combining energy taxes and subsidies

Steffen Kallbekken, Sofie Waage Skjeflo and Knut Einar Rosendahl

This study investigates the behavioral underpinnings of public support for environmental policy packages combining taxes and subsidies. The results reveal that, while support for combined policies falls between tax-only and subsidy-only levels, they are closer to tax-only support. The findings indicate that combining unpopular taxes with favorable subsidies may not significantly increase public support, contrary to some theories of policy packaging. Read more.

Oxford Open Energy

India’s role in energy transition

Solveig Aamodt, Karina Standal, Gopal K. Sarangi et. al. including Robbie Andrew from CICERO

This article takes stock of energy transition developments in India at different governance levels to offer examples and draw lessons-learned that can enhance our understanding of India’s potential role in the low-carbon energy transition, with particular focus on how to make transitions more inclusive of opportunities and address challenges in global South contexts. Being the world’s most populated country and the third-largest energy user and greenhouse gases emitter, India is key to the global transition from fossil to renewable energy. Read more.  

Energies

Breaking the Cycle or Repeat? Justice Implications of Energy Transition in the Indian Brick Industry

Karina Standal, Ayushi Saharan, Solveig Aamodt and Bhavya Batra

This article analyses the justice implications of energy efficiency measures in the brick industry in Bihar, India. The analysis is based on document analysis and fieldwork in Patna and highlights how present policies focus on regulations and financial incentives relevant for entrepreneurs with pre-existing skills, network and financial resources, but lack attention to mechanisms that reproduce the socio-economic inequality of the brick labour force. Read more.

Energy and Climate Change

Achieving net zero emissions in India's power sector: the dilemma between climate justice and energy justice

Kopal Dhandhania, Shivika Mittal and Minal Pathak

India has announced the goal of reaching net-zero emissions by 2070. Decarbonising India’s power sector has the potential to contribute substantially to its climate goals. This paper aims to determine a coal phase-out timeline within the framework of India's just transition to net zero. The assessment of the three scenarios based on techno-economic cost, socio-economic cost, and co-benefits of the transition shows that the peak of coal demand by 2040 will meet energy demand while focusing on achieving energy access and power supply security. Read more.

World Development Sustainability

The “grey” areas of the “green”: Assessing capabilities and distributional justice impacts of decentralised solar energy schemes in India

Bhavya Batra, Manish Kumar Shrivastava, Karina Standal, Gopal K. Sarangi, Solveig Aamodt

This article explores the ‘grey areas’ of the green energy transition by examining the distributional justice implications of decentralised solar energy projects in India. It focuses on the PM-KUSUM scheme, which aims to solarise the agricultural sector and improve farmers' incomes. The findings show that although the scheme creates multiple opportunity pathways, the ability to access and utilise these opportunities is unevenly distributed. Read more.

Atmospheric Chemistry and Physics

European summer precipitation

Birthe M. Steensen, Gunnar Myhre, Rachael Byrom, Ada Gjermundsen, Caroline Jouan and Camilla W. Stjern

Observations indicate that parts of Europe have experienced summer drying over recent decades. There is, however, substantial uncertainty in terms of precipitation changes projected by global climate models, underscoring the need for improved understanding to guide adaptation. This article analyses changes in European summer precipitation with global warming in 35 CMIP6 Earth system Models using a regional atmospheric energy budget framework. Read more. 

Geoscientific Model Development

Introducing Volatile Organic Compound Model Intercomparison Project (VOCMIP)

Gunnar Myhre, Øivind Hodnebrog, Srinath Krishnan, Maria Sand, Marit Sandstad, Ragnhild B. Skeie et. al. 

How well do global models capture volatile organic compounds — and what does that mean for air quality and climate? This article introduces VOCMIP, a community-wide effort to compare models against observations and improve VOC chemistry, with a special focus on formaldehyde (HCHO) and its central role in atmospheric processes. The authors invite atmospheric chemistry modelling groups to join this collaborative initiative. Read more. 

Natural Hazards and Earth System Sciences

Emergence of climate change signal in CMIP6 extreme indices

Nina Schuhen, Carley E. Iles, Marit Sandstad, Viktor Ananiev, andJana Sillmann

Climate and weather extremes are becoming more frequent due to the influence of anthropogenic climate change. Knowing when and where we can expect these changes to occur is essential for both climate change mitigation and developing adaptation measures. The results of this study provide a consistent basis for understanding and comparing the emergence of different types of extremes, and they highlight opportunities for further research into the underlying drivers, as well as impact- or region-specific risk assessments. Read more.

Resources, Conservation and Recycling

Confronting the incineration economy: costs and benefits of adopting advanced sorting and carbon capture for residual waste flows in Norway

Kim Rainer Mattson

Greenhouse gas emissions from waste incineration has been characterized as hard to abate process-based emissions due to the consistent generation of residual waste, which contains significant levels of embedded fossil carbon. The study uses LCA and LCC to assess emissions, material flows, energy use, and costs per ton of residual waste. Results show considerable environmental improvements in terms of emission mitigation via CCS and increased recycling , with a considerable trade-off with energy recovery and costs. Read more.

Environmental Research letters

The implications of overshooting 1.5 °C on Earth system tipping elements—a review

Paul D L Ritchie,Norman J Steinert, Jesse F Abrams et. al.

Global warming must peak below 2°C then return under 1.5°C as quickly as possible to limit the risk of dangerous “tipping points” , according to a reveiw which builds on a chapter of the 2025 Global Tipping Points Report. It warns that up to eight tipping points could be reached below 2°C warming. Read the press release. Read the article.

Nature

Moderate global warming does not rule out extreme global climate outcomes

Emanuele Bevacqua, Erich Fischer, Jana Sillmann & Jakob Zscheischler

Effectively communicating worst-case projections of global future climate—hereinafter referred to as worst-case climate outcomes—is essential for risk assessment and developing robust adaptation strategies to global warming. Yet, current approaches for identifying spatially consistent climate outcomes are limited, with worst-case global climates typically communicated via the average of climate model projections at high global warming levels, such as 3 °C or 4 °C above the preindustrial era. This paper shows that extreme global climate outcomes may occur even under moderate 2 °C warming for several sectors. Read more. 

Journal of Quantitative Spectroscopy and Radiative Transfer

Estimated atmospheric lifetimes, ozone depletion potentials, and climate metrics for Montreal Protocol chlorofluorocarbons lacking evaluation

Daniel Van Hoomissen, Øivind Hodnebrog and James B Burkholder

Montreal Protocol regulated chlorofluorocarbons (CFCs) lacking experimental data were evaluated computationally. FC-111 and C3 CFC infrared absorption spectra were calculated theoretically and used to estimate policy relevant climate metrics.

CFCs are potent ozone depleting and greenhouse gases.  Read more. 

AGU Advances

Aerosol-Cloud Interactions: Overcoming a Barrier to Projecting Near-Term Climate Evolution and Risk

Ulas Im, Bjørn Hallvard Samset, Athanasios Nenes et. al. 

Aerosol-cloud interactions are a major source of uncertainty in climate science, critically affecting our ability to project near-term climate evolution and assess societal risks.This uncertainty hampers robust policy advice across multiple domains—from estimating remaining carbon budgets and climate sensitivity, to anticipating regional extreme events and evaluating climate interventions such as solar radiation modification. This article outlines a path forward to overcome these barriers by leveraging emerging opportunities in satellite remote sensing, ground-based and airborne observations, high-resolution climate modeling, and machine learning. Read more. 

Global Policy

Revisiting International Political Leadership: Nordic Leadership in Informal Intergovernmental Climate Organisations

Christin Heinz-Fischer and Elin Lerum Boasson

The growing significance of informal intergovernmental organisations (IIGOs) in global politics necessitates a re-evaluation of leadership dynamics. The authors develop a theory framework that enables us to explain why countries take on leadership roles in IIGOs, with a specific focus on climate politics. Governments do not assume leadership in IIGOs because they want to shape bargaining processes within traditional and formal organisations, such as the UNFCCC; rather, they do this for reasons particular to informal international cooperation. Read more. 

Atmospheric Chemistry and Physics

Impact of present aircraft and aerosol emissions on atmospheric composition and climate: results from a model intercomparison

Yann Cohen, Didier Hauglustaine, Zosia Staniaszek, Marianne Tronstad Lund et. al.

Aircraft emissions of nitrogen oxides (NOx= NO + NO2), aerosols, and aerosol precursors provide a non-negligible contribution to the climate impact of air traffic, and the uncertainty in their climate Effective Radiative Forcing (ERF) remains significant. This study presents results from a new model intercomparison of the impact of aircraft emissions involving five state-of-the-art global models including both tropospheric and stratospheric chemistry. Read more. 

Journal of Climate

Understanding the Spread in Climate Feedbacks and Polar Amplification Using Coordinated Multimodel Experiments and CMIP6

Olivia Linke, Julien Lenhardt, Marianne T. Lund, et al. 

Polar amplification (PA) is a robust feature of climate change in coupled atmosphere–ocean general circulation models (AOGCMs), yet its magnitude varies substantially across models. Prior work showed that PA and its drivers, primarily positive feedbacks, are strongly linked to the degree of sea ice loss. Here, we assess to what extent this intermodel spread narrows when sea ice and sea surface temperatures are prescribed in a coordinated set of atmosphere-only GCM (AGCM) simulations. Read more.

Atmospheric Chemistry and Physics

Distinct drivers of recent seasonal precipitation increase over Central Asia: roles of anthropogenic aerosols and greenhouse gases

Jianing Guo, Xiaoning Xie, Gunnar Myhre et. al. 

Observational evidence reveals a pronounced wetting trend over Central Asia in recent decades, with the most substantial increases occurring during winter and summer. Yet the extent to which the drivers of these changes differ seasonally remains unknown. The authors use single-forcing experiments from the Precipitation Driver and Response Model Intercomparison Project (PDRMIP) to examine the effects of various external forcings on winter and summer precipitation across Central Asia and to explore the physical mechanisms underlying seasonal precipitation changes. Read more. 

Environmental Research: Climate

Decomposing the global and regional aerosol effective radiative forcing associated with strong versus weak air quality policies by Mid-21st century

Robert J Allen, Laura J Wilcox, Bjørn H Samset et. al. 

The Regional Aerosol Model Intercomparison Project (RAMIP) is designed to quantify the forcing and climate impacts of mid-21st century anthropogenic aerosol and precursor gas (AA) emissions reductions (both industrial and biomass burning), by comparing a weak (SSP3-7.0) versus strong (SSP1-2.6) level of air quality control aerosol emissions pathway.  Here, authors use RAMIP time-slice simulations with fixed sea surface temperatures and sea-ice distributions from nine models to quantify the aerosol effective radiative forcing (ERF), including aerosol radiation (ERFari) and aerosol cloud interactions (ERFaci). Read more. 

Advances in Statistical Climatology, Meteorology and Oceanography

Bayesian hierarchical modelling of intensity-duration-frequency curves using a climate model large ensemble

Alexander Lee Rischmuller, Benjamin Poschlod, and Jana Sillmann

Accurate modelling of extreme precipitation is vital for predicting future risks and informing adaptation strategies. Here, the authors compare and evaluate six different extreme value statistical models for hourly to 48 h extreme precipitation in southern Germany, with a primary focus on duration-dependent Generalized Extreme Value (dGEV) distributions. Read more. 

Climate Policy

Could policy sequencing increase public support for ambitious climate policies? Experimental insights from efforts to enhance battery electric vehicle adoption in Norway and Switzerland

Thomas Bernauer, Sverker C. Jagers, Steffen Kallbekken, Marina Povitkina and Maja Schoch

Conventional wisdom presumes there is a trade-off between policy effectiveness and feasibility: push policies that disincentivize undesirable behaviour and tend to be more effective are often less popular; pull policies that incentivize desired behaviour and tend to be less effective are often more popular. The authors link this presumption to recent research on policy sequencing to hypothesize that temporal policy sequencing, starting with pull and subsequently moving to push policies, could help achieve higher levels of public acceptance and thus mitigate the effectiveness- feasibility dilemma. Read more. 

Other material

Report

Decarbonization of the power sector – Views of Norwegian stakeholders

Asbjørn Torvanger

In this report stakeholders in the Norwegian electricity sector are interviewed about their perceptions and views about decarbonization of the Norwegian society. There is broad support for expanding the production of renewable power, especially land-based wind power, investing in more hydropower effect capacity, more grid development, and prioritizing more flexibility in the electricity system. There are, however, many dilemmas in terms of impacts on nature, market interventions that reduce incentives for energy saving and responding to price signals, and challenges with connecting new industry projects to the grid due to strict regulation of power and grid expansion combined with free trading of power. Read more.