| 21. |
- Vinichenko, Vadim, et al.
(författare)
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Phasing out coal for 2 °C target requires worldwide replication of most ambitious national plans despite security and fairness concerns
- 2023
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- 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.
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| 22. |
- Vowles, Tage, et al.
(författare)
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Contrasting impacts of reindeer grazing in two tundra grasslands
- 2017
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Plant communities in Arctic and alpine areas are changing due to higher temperatures and longer vegetation periods and it is uncertain how this will affect plant-herbivore dynamics. For instance, relatively fast-growing, deciduous shrub species that are the most responsive to warming may also be the most targeted by herbivores such as reindeer, giving less palatable evergreen shrubs the chance to expand. Using herbivore exclosures, we have studied how two grasslands with contrasting nutrient and moisture regimes, a dry, nutrient-poor alpine grass heath and a wet, productive low herb meadow, changed between 1995 and 2012, in grazed and ungrazed conditions. At the grass heath, evergreen low shrub abundance had more than doubled, regardless of grazer treatment, whereas at the low herb meadow, evergreen shrubs had increased only outside exclosures while deciduous tall shrubs and forbs were significantly more abundant inside exclosures. Deciduous tall shrubs were also significantly taller in exclosures. These contrasting findings suggest that the impact of herbivores is to a great deal determined by their influence on competitive interactions between plant species, and therefore depends on the underlying composition of the plant community. Consequently, as the balance in these competitive interactions is shifting due to climate warming, we conclude that the potential of herbivory to influence this balance is considerable yet highly site dependent.
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| 23. |
- Azar, Christian, 1969, et al.
(författare)
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Meeting global temperature targets-the role of bioenergy with carbon capture and storage
- 2013
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 8:3
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Tidskriftsartikel (refereegranskat)abstract
- In order to meet stringent temperature targets, active removal of CO2 from the atmosphere may be required in the long run. Such negative emissions can be materialized when well-performing bioenergy systems are combined with carbon capture and storage (BECCS). Here, we develop an integrated global energy system and climate model to evaluate the role of BECCS in reaching ambitious temperature targets. We present emission, concentration and temperature pathways towards 1.5 and 2 degrees C targets. Our model results demonstrate that BECCS makes it feasible to reach temperature targets that are otherwise out of reach, provided that a temporary overshoot of the target is accepted. Additionally, stringent temperature targets can be met at considerably lower cost if BECCS is available. However, the economic benefit of BECCS nearly vanishes if an overshoot of the temperature target is not allowed. Finally, the least-cost emission pathway over the next 50 years towards a 1.5 degrees C overshoot target with BECCS is almost identical to a pathway leading to a 2 degrees C ceiling target.
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| 24. |
- Azar, Christian, 1969, et al.
(författare)
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IPCC and the effectiveness of carbon sinks
- 2022
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 17:4
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 25. |
- Bastos Lima, Mairon G., 1984, et al.
(författare)
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Leakage and boosting effects in environmental governance: a framework for analysis
- 2019
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 14:10
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Tidskriftsartikel (refereegranskat)abstract
- In an increasingly interconnected world, leakage-broadly understood as unintended displacement of impacts caused by an environmental policy intervention-has become a major governance concern. Yet, leakage remains both loosely conceptualized and poorly understood as a phenomenon in policy making. To fill this gap and broaden the leakage research agenda, we conduct a state-of-the-art review of scientific assessments on leakage (particularly on land use) and combine it with conceptual and analytical frameworks from the environmental governance literature. We then propose a rigorous definition of leakage, discuss frequently overlooked political dimensions, and develop a typology of leakage pathways. Our analysis of leakage through a governance lens yields five core insights: (1) Leakage is not simply a mechanistic phenomenon, but a complex governance issue involving questions of institutional fit, interactions, and political agency. (2) Although the land use literature traditionally focuses on leakage through markets or activity displacement, a governance lens shows that it also occurs through information, motivation, or institutional channels. (3) As policy-makers may act strategically, the unintentionally of leakage should not be assumed but rather become an object of research. (4) A phenomenon not initially regarded as leakage can come to be framed as such through the action of 'problem brokers' and changes in policy fields. (5) Policy-makers and researchers should broaden their focus from only avoiding leakage to seeking positive spillovers and institutional synergies. These insights are illustrated with examples from two cases relating to land use policy in Brazil and Southeast Asia.
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| 26. |
- Bjorn, A., et al.
(författare)
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Review of life-cycle based methods for absolute environmental sustainability assessment and their applications
- 2020
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Ingår i: Environmental Research Letters. - : IOP Publishing Ltd. - 1748-9326 .- 1748-9318. ; 15:8
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Tidskriftsartikel (refereegranskat)abstract
- In many regions and at the planetary scale, human pressures on the environment exceed levels that natural systems can sustain. These pressures are caused by networks of human activities, which often extend across countries and continents due to global trade. This has led to an increasing requirement for methods that enable absolute environmental sustainability assessment (AESA) of anthropogenic systems and which have a basis in life cycle assessment (LCA). Such methods enable the comparison of environmental impacts of products, companies, nations, etc, with an assigned share of environmental carrying capacity for various impact categories. This study is the first systematic review of LCA-based AESA methods and their applications. After developing a framework for LCA-based AESA methods, we identified 45 relevant studies through an initial survey, database searches and citation analysis. We characterized these studies according to their intended application, impact categories, basis of carrying capacity estimates, spatial differentiation of environmental model and principles for assigning carrying capacity. We then characterized all method applications and synthesized their results. Based on this assessment, we present recommendations to practitioners on the selection and use of existing LCA-based AESA methods, as well as ways to perform assessments and communicate results to decision-makers. Furthermore, we identify future research priorities intended to extend coverage of all components of the proposed method framework, improve modeling and increase the applicability of methods. © 2020 The Author(s).
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| 27. |
- Blennow, Kristina
(författare)
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Are forest disturbances amplifying or canceling out climate change-induced productivity changes in European forests?
- 2017
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 12
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Tidskriftsartikel (refereegranskat)abstract
- Recent studies projecting future climate change impacts on forests mainly consider either the effects of climate change on productivity or on disturbances. However, productivity and disturbances are intrinsically linked because 1) disturbances directly affect forest productivity (e.g. via a reduction in leaf area, growing stock or resource-use efficiency), and 2) disturbance susceptibility is often coupled to a certain development phase of the forest with productivity determining the time a forest is in this specific phase of susceptibility. The objective of this paper is to provide an overview of forest productivity changes in different forest regions in Europe under climate change, and partition these changes into effects induced by climate change alone and by climate change and disturbances. We present projections of climate change impacts on forest productivity from state-of-the-art forest models that dynamically simulate forest productivity and the effects of the main European disturbance agents (fire, storm, insects), driven by the same climate scenario in seven forest case studies along a large climatic gradient throughout Europe. Our study shows that, in most cases, including disturbances in the simulations exaggerate ongoing productivity declines or cancel out productivity gains in response to climate change. In fewer cases, disturbances also increase productivity or buffer climate-change induced productivity losses, e.g. because low severity fires can alleviate resource competition and increase fertilization. Even though our results cannot simply be extrapolated to other types of forests and disturbances, we argue that it is necessary to interpret climate change-induced productivity and disturbance changes jointly to capture the full range of climate change impacts on forests and to plan adaptation measures.
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| 28. |
- Deng, K., et al.
(författare)
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More frequent summer heat waves in southwestern China linked to the recent declining of Arctic sea ice
- 2020
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 15:7
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Tidskriftsartikel (refereegranskat)abstract
- Southwestern China (SWC) has suffered from increasing frequency of heat wave (HW) in recent summers. While the local drought-HW connection is one obvious mechanism for this change, remote controls remain to be explored. Based on ERA-5 reanalysis, it is found that the SWC summer HWs are significantly correlated with sea-ice losses in the Barents Sea, Kara Sea and the Arctic pole. The reduction of Arctic sea ice can cause low pressure anomalies over the polar region due to increased heat-flux exchanges at the sea-air interface, which subsequently triggers southeastward Rossby wave trains propagating from northern Europe to East Asia that induce anomalous anticyclone over SWC. As a result, the North Pacific subtropical high extends westward, accompanied by divergent winds, decreased cloud cover and increased insolation in SWC, which leads to above-normal air temperatures there. In addition, the East Asian westerly jet stream is shifted northward, which enhances (reduces) the moisture convergence in North China (SWC), resulting in prominently drier soil in SWC. Therefore, the sea ice - forced changes in atmospheric circulation and surface conditions favor the occurrences of SWC summer HWs. © 2020 The Author(s). Published by IOP Publishing Ltd.
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| 29. |
- Einarsson, Rasmus, 1988, et al.
(författare)
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The nitrogen footprint of Swedish food consumption
- 2022
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9318 .- 1748-9326. ; 17:10
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Tidskriftsartikel (refereegranskat)abstract
- Food systems are major drivers of environmental and health impacts. While the emissions and other pressures causing these impacts mainly occur in primary agricultural production, the deeper causes and much of the mitigation potential are distributed throughout food systems, including dietary choices and multiple inefficiencies in the whole chain from agricultural production to consumption and waste management. An environmental indicator based on this systems perspective is the nitrogen (N) footprint, defined as the emissions of reactive N due to the consumption of an individual or other entity. Here, we present a method to estimate the N footprint of Swedish food consumption, using a detailed inventory of agricultural production, food and feed processing, food waste, waste management, and wastewater treatment. Limitations of data sources and methods are discussed in detail. The estimated Swedish food N footprint is 12.1 kg N capita(-1) yr(-1), of which 42% is emitted in Swedish production, 38% in production abroad, 1% in consumer waste management, and 19% in wastewater treatment. Animal food products account for 81% of the food N footprint and 70% of the protein intake. Average protein intake exceeds nutritional requirements by about 60%, which suggests that at least 35% reduction of food-related reactive N emissions could be achieved through dietary change. Of the apparent food N consumption (6.9 kg N capita(-1) yr(-1)), about 22% is food waste N (1.5 kg N capita(-1) yr(-1)). We estimate that 76% of food waste N is unavoidable (bones and other parts not commonly eaten). Avoidable food waste is about 7% of the edible food supply, implying that a hypothetical complete elimination of food waste would reduce emissions by about 7%. In summary, we present a detailed method, discuss its limitations, and demonstrate possible uses of the N footprint as a complement to existing territorial and sectoral environmental indicators.
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| 30. |
- Johansson, Daniel, 1975, et al.
(författare)
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The role of negative carbon emissions in reaching the Paris climate targets: The impact of target formulation in integrated assessment models
- 2020
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326 .- 1748-9318. ; 15:12
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Tidskriftsartikel (refereegranskat)abstract
- Global net-negative carbon emissions are prevalent in almost all emission pathways that meet the Paris temperature targets. In this paper, we generate and compare cost-effective emission pathways that satisfy two different types of climate targets. First, the common approach of a radiative forcing target that has to be met by the year 2100 (RF2100), and, second, a temperature ceiling target that has to be met over the entire period, avoiding any overshoot. Across two integrated assessment models (IAMs), we found that the amount of net-negative emissions - when global net emissions fall below zero - depends to a large extent on how the target is represented, i.e. implemented in the model. With a temperature ceiling (no temperature overshoot), net-negative emissions are limited and primarily a consequence of trade-offs with non-CO2 emissions, whereas net-negative emissions are significant for the RF2100 target (temperature overshoot). The difference becomes more pronounced with more stringent climate targets. This has important implications: more stringent near-term emission reductions are needed when a temperature ceiling is implemented compared to when an RF2100 target is implemented. Further, in one IAM, for our base case assumptions, the cost-effective negative carbon emissions (i.e. gross anthropogenic removals) do not depend to any significant extent on how the constraint is implemented, only, largely, on the ultimate stringency of the constraint. Hence, for a given climate target stringency in 2100, the RF2100 target and the temperature ceiling may result in essentially the same amount of negative carbon emissions. Finally, it is important that IAM demonstrate results for diverse ways of implementing a climate target, since the implementation has implications for the level of near-term emissions and the perceived need for net-negative emissions (beyond 2050).
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