CICERO Research Archive (CICERO Senter for klimaforskning)
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How well are aerosol-cloud interactions represented in climate models? - Part 1: Understanding the sulfate aerosol production from the 2014-15 Holuhraun eruption
Get PDFFor over 6 months, the 2014–2015 effusive eruption at Holuhraun, Iceland, injected considerable amounts of sulfur dioxide (SO2) into the lower troposphere with a daily rate of up to one-third of the global emission rate, causing extensive air pollution across Europe. The large injection of SO2, which oxidises to form sulfate aerosol (), provides a natural experiment offering an ideal opportunity to scrutinise state-of-the-art general circulation models' (GCMs) representation of aerosol–cloud interactions (ACIs). Here we present Part 1 of a two-part model inter-comparison using the Holuhraun eruption as a framework to analyse ACIs. We use SO2 retrievals from the Infrared Atmospheric Sounding Interferometer (IASI) instrument and ground-based measurements of SO2 and mass concentrations across Europe, in conjunction with a trajectory analysis using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model, to assess the spatial and chemical evolution of the volcanic plume as simulated by five GCMs and a chemical transport model (CTM). IASI retrievals of plume altitude and SO2 column load reveal that the volcanic perturbation is largely contained within the lower troposphere. Compared to the satellite observations, the models capture the spatial evolution and vertical variability of the plume reasonably well, although the models often overestimate the plume altitude. HYSPLIT trajectories are used to attribute to Holuhraun emissions 111 instances of elevated sulfurous surface mass concentrations recorded at European Monitoring and Evaluation Programme (EMEP) stations during September and October 2014. Comparisons with the simulated concentrations show that the modelled ratio of SO2 to during these pollution episodes is often underestimated and overestimated for the young and mature plume, respectively. Models with finer vertical resolutions near the surface are found to better capture these elevated sulfurous ground-level concentrations. Using an exponential function to describe the decay of observed surface mass concentration ratios of SO2 to with plume age, the in-plume oxidation rate constant is estimated as 0.032 ± 0.002 h−1 (1.30 ± 0.08 d e-folding time), with a near-vent ratio of 25 ± 5 (µg m−3 of SO2 µg m−3 of ). The majority of the corresponding derived modelled oxidation rate constants are lower than the observed estimate. This suggests that the representation of the oxidation pathway/s in the simulated plumes is too slow. Overall, despite their coarse spatial resolutions, the six models show reasonable skill in capturing the spatial and chemical evolution of the Holuhraun plume. This capable representation of the underlying aerosol perturbation is essential to enable the investigation of the eruption's impact on ACIs in the second part of this study.publishedVersio
Modification of heat-related effects on mortality by air pollution concentration, at small-area level, in the Attica prefecture, Greece
Get PDFThe independent effects of short-term exposure to increased air temperature and air pollution on mortality are well-documented. There is some evidence indicating that elevated concentrations of air pollutants may lead to increased heat-related mortality, but this evidence is not consistent. Most of these effects have been documented through time-series studies using city-wide data, rather than at a finer spatial level. In our study, we examined the possible modification of the heat effects on total and cause-specific mortality by air pollution at municipality level in the Attica region, Greece, during the warm period of the years 2000 to 2016.publishedVersio
A perspective on the next generation of Earth system model scenarios: Towards representative emission pathways (REPs)
Get PDFIn every Intergovernmental Panel on Climate Change (IPCC) Assessment cycle, a multitude of scenarios are assessed, with different scope and emphasis throughout the various Working Group reports and special reports, as well as their respective chapters. Within the reports, the ambition is to integrate knowledge on possible climate futures across the Working Groups and scientific research domains based on a small set of “framing pathways” such as the so-called representative concentration pathways (RCPs) in the Fifth IPCC Assessment Report (AR5) and the shared socioeconomic pathway (SSP) scenarios in the Sixth Assessment Report (AR6). This perspective, initiated by discussions at the IPCC Bangkok workshop in April 2023 on the “Use of Scenarios in AR6 and Subsequent Assessments”, is intended to serve as one of the community contributions to highlight the needs for the next generation of framing pathways that is being advanced under the Coupled Model Intercomparison Project (CMIP) umbrella, which will influence or even predicate the IPCC AR7 consideration of framing pathways. Here we suggest several policy research objectives that such a set of framing pathways should ideally fulfil, including mitigation needs for meeting the Paris Agreement objectives, the risks associated with carbon removal strategies, the consequences of delay in enacting that mitigation, guidance for adaptation needs, loss and damage, and for achieving mitigation in the wider context of societal development goals. Based on this context, we suggest that the next generation of climate scenarios for Earth system models should evolve towards representative emission pathways (REPs) and suggest key categories for such pathways. These framing pathways should address the most critical mitigation policy and adaptation plans that need to be implemented over the next 10 years. In our view, the most important categories are those relevant in the context of the Paris Agreement long-term goal, specifically an immediate action (low overshoot) 1.5 °C pathway and a delayed action (high overshoot) 1.5 °C pathway. Two other key categories are a pathway category approximately in line with current (as expressed by 2023) near- and long-term policy objectives, as well as a higher-emission category that is approximately in line with “current policies” (as expressed by 2023). We also argue for the scientific and policy relevance in exploring two “worlds that could have been”. One of these categories has high-emission trajectories well above what is implied by current policies and the other has very-low-emission trajectories which assume that global mitigation action in line with limiting warming to 1.5 °C without overshoot had begun in 2015. Finally, we note that the timely provision of new scientific information on pathways is critical to inform the development and implementation of climate policy. Under the Paris Agreement, for the second global stocktake, which will occur in 2028, and to inform subsequent development of nationally determined contributions (NDCs) up to 2040, scientific inputs are required by 2027. These needs should be carefully considered in the development timeline of community modelling activities, including those under CMIP7.publishedVersio
Impacts og Gobal Warming on Regional Energy and Economy: uneven Consequences arasing from Global Warming-induced Heating and Cooling Demand of Households
Get PDFThe impacts of global warming vary across regions. This paper studies the distributional implications of global warming impacts on household energy use for heating and cooling and the induced macroeconomic responses under different scenarios. Our research updates the direct impact of global warming on household energy demand in 140 regions worldwide by utilizing existing estimations of damage functions related to temperature changes. Subsequently, the updated direct impact is used in a global static computable general equilibrium (CGE) model to evaluate the macroeconomic responses. We find that at the global level, the market effects cause a reduction in the direct impact on the demand for oil and gas, while that for electricity displays a positive but moderate growth. Whereas the regional effects vary across countries and lead to changes in both directions, in which the autonomous adaptation embodied in the global market plays a vital role. Furthermore, we find strong inequality in the socioeconomic responses to global warming across regions. Notably, low-income countries are most strongly affected by increased primary energy use and decreased gross domestic product (GDP). Disparities in the impacts on carbon-based energy sources yield a near-perfect inequality as per the adjusted Gini index for CO2 emission changes, which potentially intensify the distributional consequences of global climate change.Impacts og Gobal Warming on Regional Energy and Economy: uneven Consequences arasing from Global Warming-induced Heating and Cooling Demand of HouseholdspublishedVersio
Human heat stress could offset potential economic benefits of CO<inf>2</inf> fertilization in crop production under a high-emissions scenario
No full textClimate change can significantly affect food production in many ways. Changes in greenhouse gases, temperature, and rainfall directly influence crop productivity, sometimes increasing yield through a mechanism known as the carbon dioxide fertilization effect. However, agricultural production in many countries also relies on physically demanding manual labor, primarily outside, and, as temperatures rise, heat stress on agricultural workers can reduce labor capacity. Consequential climate change impacts on food availability and affordability are a major societal concern, yet the specific and combined impacts on agricultural production remain highly uncertain. An assessment of the future impacts of climate change on the production and prices of four of the world’s most consumed crops (maize, wheat, soybean, and rice) reveals that a rise in heat stress will lower agricultural labor capacity and increase labor costs in Africa and Asia. This could offset the potential economic benefits of higher yields due to elevated levels of CO2. Proactive adaptation measures, such as mechanization deployment, are needed to reduce the vulnerability to heat stress.publishedVersio
High-Resolution Modeling and Projecting Local Dynamics of Differential Vulnerability to Urban Heat Stress
Get PDFClimate change-induced heat stress has significant effects on human health, and is influenced by a wide variety of factors. Most assessments of future heat-related risks however are based on coarse resolution projections of heat hazards and overlook the contribution of relevant factors other than climate change to the negative impacts on health. Research highlights sociodemographic disparities related to heat stress vulnerability, especially among older adults, women and individuals with low socioeconomic status, leading to higher morbidity and mortality rates. There is thus an urgent need for detailed, local information on demographic characteristics underlying vulnerability with refined spatial resolution. This study aims to address the research gaps by presenting a new population projection exercise at high-resolution based on the Bayesian modeling framework for the case study of Madrid, using demographic data under the scenarios compatible with the Shared Socioeconomic Pathways. We examine the spatial and temporal distribution of population subgroups at the intra-urban level within Madrid. Our findings reveal a concentration of vulnerable populations, as measured by their age, sex and educational attainment level in some of the city's most disadvantaged neighborhoods. These vulnerable clusters are projected to widen in the future unless a sustainable trajectory is realized, driving vulnerability dynamics toward a more uniform and resilient change. These results can guide local adaptation efforts and support climate justice initiatives to protect vulnerable communities in urban environments.publishedVersio
Scoping Review of Climate Change Adaptation Interventions for Health: Implications for Policy and Practice
Get PDFClimate change is among the greatest threats to health in the 21st century, requiring the urgent scaling-up of adaptation interventions. We aim to summarise adaptation interventions that were funded by the Belmont Forum and the European Union, the largest global funders of climate change and health research. A systematic search was conducted (updated February 2023) to identify articles on adaptation interventions for health within this funding network. The data extracted included study characteristics, types of interventions, and study outcomes. The results were synthesised narratively within the PRISMA-ScR guidelines. A total of 197 articles were screened, with 37 reporting on adaptation interventions. The majority of interventions focused on the general population (n = 17), with few studies examining high-risk populations such as pregnant women and children (n = 4) or migrants (n = 0). Targeted interventions were mostly aimed at behavioural change (n = 8) and health system strengthening (n = 6), while interventions with mitigation co-benefits such as nature-based solutions (n = 1) or the built environment (n = 0) were limited. The most studied climate change hazard was extreme heat (n = 26). Several studies reported promising findings, principally regarding interventions to counter heat impacts on workers and pregnant women and improving risk awareness in communities. These findings provide a platform on which to expand research and public health interventions for safeguarding public health from the effects of climate change.publishedVersio
Atmospheric health burden across the century and the accelerating impact of temperature compared to pollution
Get PDFAnthropogenic emissions alter atmospheric composition and therefore the climate, with implications for air pollution- and climate-related human health. Mortality attributable to air pollution and non-optimal temperature is a major concern, expected to shift under future climate change and socioeconomic scenarios. In this work, results from numerical simulations are used to assess future changes in mortality attributable to long-term exposure to both non-optimal temperature and air pollution simultaneously. Here we show that under a realistic scenario, end-of-century mortality could quadruple from present-day values to around 30 (95% confidence level:12-53) million people/year. While pollution-related mortality is projected to increase five-fold, temperature-related mortality will experience a seven-fold rise, making it a more important health risk factor than air pollution for at least 20% of the world’s population. These findings highlight the urgent need to implement stronger climate policies to prevent future loss of life, outweighing the benefits of air quality improvements alone.publishedVersio
Digitised demand response in practice: The role of digital housekeeping for smart energy technologies
Get PDFThe renewable energy transition requires more flexible electricity consumption. This article follows up on Norwegian plans to achieve this through demand response and a piloting of smart home technology targeting indoor heating, which we call Smart Energy Technology (SET). Based on 17 in-depth interviews with participants in a technology pilot project, we map the work required to keep the SET system running, how it impacted electricity-consuming household practices, and analyse why use of the system varied widely among participants. We show that the system in question was too complex for other than exceptionally skilled and motivated users, who engaged in extensive “digital housekeeping”. Other users were navigating a complex Norwegian electricity market using technology they found difficult to operate. This was linked with limited system use, which lowered the energy efficiency contribution of the smart system. Smart systems and their use are highly gendered and have the potential both to challenge and reinforce gendered divisions of labour. More research into the gendered impacts of smart systems in Norway is needed. Simpler and more user-friendly systems are necessary for future pilot projects, more hands-on training for users in such pilots is required, and the daily work required to operate complex smart systems should be recognised more clearly by both smart system developers and policy makers.publishedVersio
A review of coarse mineral dust in the Earth system
Get PDFMineral dust particles suspended in the atmosphere span more than three orders of magnitude in diameter, from <0.1 μm to more than 100 μm. This wide size range makes dust a unique aerosol species with the ability to interact with many aspects of the Earth system, including radiation, clouds, hydrology, atmospheric chemistry, and biogeochemistry. This review focuses on coarse and super-coarse dust aerosols, which we respectively define as dust particles with a diameter of 2.5–10 μm and 10–62.5 μm. We review several lines of observational evidence indicating that coarse and super-coarse dust particles are transported farther than previously expected and that the abundance of these particles is substantially underestimated in current global models. We synthesize previous studies that used observations, theories, and model simulations to highlight the impacts of coarse and super-coarse dust aerosols on the Earth system, including their effects on dust-radiation interactions, dust-cloud interactions, atmospheric chemistry, and biogeochemistry. Specifically, coarse and super-coarse dust aerosols produce a net positive direct radiative effect (warming) at the top of the atmosphere and can modify temperature and water vapor profiles, influencing the distribution of clouds and precipitation. In addition, coarse and supercoarse dust aerosols contribute a substantial fraction of ice-nucleating particles, especially at temperatures above –23 ◦C. They also contribute a substantial fraction to the available reactive surfaces for atmospheric processing and the dust deposition flux that impacts land and ocean biogeochemistry by supplying important nutrients such as iron and phosphorus. Furthermore, we examine several limitations in the representation of coarse and supercoarse dust aerosols in current model simulations and remote-sensing retrievals. Because these limitations substantially contribute to the uncertainties in simulating the abundance and impacts of coarse and super-coarse dust aerosols, we offer some recommendations to facilitate future studies. Overall, we conclude that an accuratepublishedVersio