Pub Date : 2023-08-14DOI: 10.1088/2752-5295/aceff2
A. King, H. Douglas, L. Harrington, E. Hawkins, Alexander Borowiak
The emergence of climate change from background variability is a useful metric for identifying changes in local climate which may affect people and ecosystems. Studies have found that equatorial regions, which are typically poorer, experience clearer climate change emergence over the observational record and in model projections. Here, we perform the first analysis of people’s experienced climate change relative to background variability, and we examine where people have already lived through an emergence of local warming. We calculate signal-to-noise (S/N) ratios and combine these with demographic data to compute local emergence of warming over human lifetimes. Younger people have typically experienced less clear emergence of a climate change signal over their lifetimes to date. Over a given time period, tropical, lower-income areas have experienced higher S/N than extratropical and typically higher-income areas. However, this is counter-balanced by the younger populations of these areas such that the median experienced S/N ratio is similar between the wealthiest and poorest parts of the world. Given projected ageing of low-income regions, it is imperative that substantial climate action is taken to avoid local climates becoming unrecognizable within human lifetimes.
{"title":"Climate change emergence over people’s lifetimes","authors":"A. King, H. Douglas, L. Harrington, E. Hawkins, Alexander Borowiak","doi":"10.1088/2752-5295/aceff2","DOIUrl":"https://doi.org/10.1088/2752-5295/aceff2","url":null,"abstract":"The emergence of climate change from background variability is a useful metric for identifying changes in local climate which may affect people and ecosystems. Studies have found that equatorial regions, which are typically poorer, experience clearer climate change emergence over the observational record and in model projections. Here, we perform the first analysis of people’s experienced climate change relative to background variability, and we examine where people have already lived through an emergence of local warming. We calculate signal-to-noise (S/N) ratios and combine these with demographic data to compute local emergence of warming over human lifetimes. Younger people have typically experienced less clear emergence of a climate change signal over their lifetimes to date. Over a given time period, tropical, lower-income areas have experienced higher S/N than extratropical and typically higher-income areas. However, this is counter-balanced by the younger populations of these areas such that the median experienced S/N ratio is similar between the wealthiest and poorest parts of the world. Given projected ageing of low-income regions, it is imperative that substantial climate action is taken to avoid local climates becoming unrecognizable within human lifetimes.","PeriodicalId":432508,"journal":{"name":"Environmental Research: Climate","volume":"41 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128704621","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-09DOI: 10.1088/2752-5295/aceea2
Shi Zhou, Yu‐Chiao Liang, I. Mitevski, L. Polvani
Arctic amplification (AA), referring to the phenomenon of amplified warming in the Arctic compared to the warming in the rest of the globe, is generally attributed to the increasing concentrations of carbon dioxide (CO2) in the atmosphere. However, little attention has been paid to the mechanisms and quantitative variations of AA under decreasing levels of CO2, when cooling where the Arctic region is considerably larger than over the rest of the planet. Analyzing climate model experiments forced with a wide range of CO2 concentrations (from 1/8× to 8×CO2, with respect to preindustrial levels), we show that AA indeed occurs under decreasing CO2 concentrations, and it is stronger than AA under increasing CO2 concentrations. Feedback analysis reveals that the Planck, lapse-rate, and albedo feedbacks are the main contributors to producing AAs forced by CO2 increase and decrease, but the stronger lapse-rate feedback associated with decreasing CO2 level gives rise to stronger AA. We further find that the increasing CO2 concentrations delay the peak month of AA from November to December or January, depending on the forcing strength. In contrast, decreasing CO2 levels cannot shift the peak of AA earlier than October, as a consequence of the maximum sea-ice increase in September which is independent of forcing strength. Such seasonality changes are also presented in the lapse-rate feedback, but do not appear in other feedbacks nor in the atmospheric and oceanic heat transport processeses. Our results highlight the strongly asymmetric responses of AA, as evidenced by the different changes in its intensity and seasonality, to the increasing and decreasing CO2 concentrations. These findings have significant implications for understanding how carbon removal could impact the Arctic climate, ecosystems, and socio-economic activities.
{"title":"Stronger Arctic amplification produced by decreasing, not increasing, CO2 concentrations","authors":"Shi Zhou, Yu‐Chiao Liang, I. Mitevski, L. Polvani","doi":"10.1088/2752-5295/aceea2","DOIUrl":"https://doi.org/10.1088/2752-5295/aceea2","url":null,"abstract":"Arctic amplification (AA), referring to the phenomenon of amplified warming in the Arctic compared to the warming in the rest of the globe, is generally attributed to the increasing concentrations of carbon dioxide (CO2) in the atmosphere. However, little attention has been paid to the mechanisms and quantitative variations of AA under decreasing levels of CO2, when cooling where the Arctic region is considerably larger than over the rest of the planet. Analyzing climate model experiments forced with a wide range of CO2 concentrations (from 1/8× to 8×CO2, with respect to preindustrial levels), we show that AA indeed occurs under decreasing CO2 concentrations, and it is stronger than AA under increasing CO2 concentrations. Feedback analysis reveals that the Planck, lapse-rate, and albedo feedbacks are the main contributors to producing AAs forced by CO2 increase and decrease, but the stronger lapse-rate feedback associated with decreasing CO2 level gives rise to stronger AA. We further find that the increasing CO2 concentrations delay the peak month of AA from November to December or January, depending on the forcing strength. In contrast, decreasing CO2 levels cannot shift the peak of AA earlier than October, as a consequence of the maximum sea-ice increase in September which is independent of forcing strength. Such seasonality changes are also presented in the lapse-rate feedback, but do not appear in other feedbacks nor in the atmospheric and oceanic heat transport processeses. Our results highlight the strongly asymmetric responses of AA, as evidenced by the different changes in its intensity and seasonality, to the increasing and decreasing CO2 concentrations. These findings have significant implications for understanding how carbon removal could impact the Arctic climate, ecosystems, and socio-economic activities.","PeriodicalId":432508,"journal":{"name":"Environmental Research: Climate","volume":"93 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131413992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-09DOI: 10.1088/2752-5295/acee9f
N. Freychet, A. Schurer, A. Ballinger, Laura Suarez‐Gutierrez, C. Timmreck
Very large volcanic eruptions have substantial impacts on the climate, causing global cooling and major changes to the hydrological cycle. While most studies have focused on changes to mean climate, here we use a large ensemble to assess the impact on extreme climate for three years following tropical and extratropical eruptions of different sulfur emission strength. We focus on the impact of an extremely large eruption, injecting 40 Tg sulfur into the stratosphere, which could be expected to occur approximately twice a millennium. Our findings show that the eruption would have a profound effect on large areas of the globe, resulting in extremely rare drought events that under normal circumstances would occur once every century becoming very likely. Several regions such as West Africa, South and East Asia and the Maritime continent are particularly affected with the expected climate shifting well outside the usual range, by up to five standard deviations. These results have important consequences as they indicate that a severe drought in multiple breadbasket regions should be expected following a large eruption. The risk of heavy rainfall tends to decrease over the same regions but by a reduced amount, heatwaves become extremely rare, however the chance of extreme Winter cold surges do not increase by a corresponding amount, since widespread parts of the Northern Hemisphere display a winter warming. Our results show that the location of the eruption is crucial for the change in extremes, with overall changes larger for a Northern Hemisphere eruption than a tropical and Southern Hemisphere eruption, although there is a regional dependency. Simulations of different eruptions with similar forcing distributions but with different sizes are consistent with a linear relationship, however for smaller eruptions the internal variability tends to become dominant and the effect on extreme climate less detectable.
{"title":"Assessing the impact of very large volcanic eruptions on the risk of extreme climate events","authors":"N. Freychet, A. Schurer, A. Ballinger, Laura Suarez‐Gutierrez, C. Timmreck","doi":"10.1088/2752-5295/acee9f","DOIUrl":"https://doi.org/10.1088/2752-5295/acee9f","url":null,"abstract":"Very large volcanic eruptions have substantial impacts on the climate, causing global cooling and major changes to the hydrological cycle. While most studies have focused on changes to mean climate, here we use a large ensemble to assess the impact on extreme climate for three years following tropical and extratropical eruptions of different sulfur emission strength. We focus on the impact of an extremely large eruption, injecting 40 Tg sulfur into the stratosphere, which could be expected to occur approximately twice a millennium. Our findings show that the eruption would have a profound effect on large areas of the globe, resulting in extremely rare drought events that under normal circumstances would occur once every century becoming very likely. Several regions such as West Africa, South and East Asia and the Maritime continent are particularly affected with the expected climate shifting well outside the usual range, by up to five standard deviations. These results have important consequences as they indicate that a severe drought in multiple breadbasket regions should be expected following a large eruption. The risk of heavy rainfall tends to decrease over the same regions but by a reduced amount, heatwaves become extremely rare, however the chance of extreme Winter cold surges do not increase by a corresponding amount, since widespread parts of the Northern Hemisphere display a winter warming. Our results show that the location of the eruption is crucial for the change in extremes, with overall changes larger for a Northern Hemisphere eruption than a tropical and Southern Hemisphere eruption, although there is a regional dependency. Simulations of different eruptions with similar forcing distributions but with different sizes are consistent with a linear relationship, however for smaller eruptions the internal variability tends to become dominant and the effect on extreme climate less detectable.","PeriodicalId":432508,"journal":{"name":"Environmental Research: Climate","volume":"110 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117188966","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-09DOI: 10.1088/2752-5295/acee9e
R. Bintanja, R. Graversen, M. Kolbe
Polar warming, ice melt and strong precipitation events are strongly affected by episodic poleward advection of warm and moist air (Woods and Caballero 2016 J. Clim. 29 4473–85; Wille et al 2019 Nat. Geosci. 12 911–6), which, in turn, is linked to variability in poleward moisture transport (PMT) (Nash et al 2018 J. Geophys. Res. Atmos. 123 6804–21). However, processes governing regional impacts of PMT as well as long-term trends remain largely unknown. Here we use an ensemble of state-of-the-art global climate models in standardized scenario simulations (1850–2100) to show that both the Arctic and the Antarctic exhibit distinct geographical patterns of PMT-related warming. Specifically, years with high PMT experience considerable warming over subarctic Eurasia and West-Antarctica (Raphael et al 2016 Bull. Am. Meteorol. Soc. 97 111–21), whereas precipitation is distributed more evenly over the polar regions. The warming patterns indicate preferred routes of atmospheric rivers (Woods and Caballero 2016 J. Clim. 29 4473–85), which may regionally enhance atmospheric moisture content, cloud cover, and downward longwave radiative heating in years with comparatively high PMT (Scott et al 2019 J. Clim. 32 665–84). Trend-analyses reveal that the link between PMT-variability and regional precipitation patterns will weaken in both polar regions. Even though uncertainties associated with intermodel differences are considerable, the advection of warm and moist air associated with PMT-variability is likely to increasingly cause mild conditions in both polar regions, which in the Arctic will reinforce sea-ice melt. Similarly, the results suggest that warm years in West-Antarctica disproportionally contribute to ice sheet melt (Trusel et al 2015 Nat. Geosci. 8 927–32), enhancing the risk of ice-sheet instabilities causing accelerated and sudden sea-level rise.
极地变暖、冰融化和强降水事件受到暖湿空气向极地平流的强烈影响(Woods and Caballero, 2016 . J.气候，29 4473-85;Wille et al . 2019地球科学学报，12 911-6)，这反过来又与极地水分输送(PMT)的变化有关(Nash et al . 2018 J. Geophys。Res. Atmos. 123 6804-21)。然而，控制PMT区域影响的过程以及长期趋势在很大程度上仍然未知。在这里，我们在标准化情景模拟(1850-2100)中使用了最先进的全球气候模式集合，以表明北极和南极都表现出与pmt相关的不同的变暖地理模式。具体来说，PMT高的年份在欧亚亚北极和南极洲西部经历了相当大的变暖(Raphael et al . 2016 Bull)。点。Meteorol。Soc. 97 111-21)，而降水在极地地区分布更为均匀。变暖模式表明了大气河流的优先路径(Woods and Caballero 2016 J. Clim. 29 4473-85)，这可能会在PMT相对较高的年份区域增强大气含水量、云量和向下的长波辐射加热(Scott et al . 2019 J. Clim. 32 665-84)。趋势分析表明，在两极地区，pmt变率与区域降水模式之间的联系将减弱。尽管与模式间差异相关的不确定性相当大，但与pmt变率相关的暖湿空气平流可能越来越多地在两极地区造成温和条件，这将在北极加强海冰融化。同样，结果表明，南极洲西部的温暖年份不成比例地促进了冰盖融化(Trusel et al . 2015 Nat. geosi . 8 927-32)，增加了冰盖不稳定导致海平面加速和突然上升的风险。
{"title":"Regional polar warming linked to poleward moisture transport variability","authors":"R. Bintanja, R. Graversen, M. Kolbe","doi":"10.1088/2752-5295/acee9e","DOIUrl":"https://doi.org/10.1088/2752-5295/acee9e","url":null,"abstract":"Polar warming, ice melt and strong precipitation events are strongly affected by episodic poleward advection of warm and moist air (Woods and Caballero 2016 J. Clim. 29 4473–85; Wille et al 2019 Nat. Geosci. 12 911–6), which, in turn, is linked to variability in poleward moisture transport (PMT) (Nash et al 2018 J. Geophys. Res. Atmos. 123 6804–21). However, processes governing regional impacts of PMT as well as long-term trends remain largely unknown. Here we use an ensemble of state-of-the-art global climate models in standardized scenario simulations (1850–2100) to show that both the Arctic and the Antarctic exhibit distinct geographical patterns of PMT-related warming. Specifically, years with high PMT experience considerable warming over subarctic Eurasia and West-Antarctica (Raphael et al 2016 Bull. Am. Meteorol. Soc. 97 111–21), whereas precipitation is distributed more evenly over the polar regions. The warming patterns indicate preferred routes of atmospheric rivers (Woods and Caballero 2016 J. Clim. 29 4473–85), which may regionally enhance atmospheric moisture content, cloud cover, and downward longwave radiative heating in years with comparatively high PMT (Scott et al 2019 J. Clim. 32 665–84). Trend-analyses reveal that the link between PMT-variability and regional precipitation patterns will weaken in both polar regions. Even though uncertainties associated with intermodel differences are considerable, the advection of warm and moist air associated with PMT-variability is likely to increasingly cause mild conditions in both polar regions, which in the Arctic will reinforce sea-ice melt. Similarly, the results suggest that warm years in West-Antarctica disproportionally contribute to ice sheet melt (Trusel et al 2015 Nat. Geosci. 8 927–32), enhancing the risk of ice-sheet instabilities causing accelerated and sudden sea-level rise.","PeriodicalId":432508,"journal":{"name":"Environmental Research: Climate","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131378710","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-09DOI: 10.1088/2752-5295/aceea1
E. Lloyd, T. Shepherd
Attribution—the explanation of an observed change in terms of multiple causal factors—is the cornerstone of climate-change science. For anthropogenic climate change (ACC), the central causal factor is evidently ACC itself, and one of the primary tools used to reveal ACC is aggregation, or grouping together, of data, e.g. global mean surface temperature. Whilst this approach has served climate-change science well, the landscape is changing rapidly. First, there is an increasing focus on regional or local aspects of climate change, and on singular or unprecedented events, which require varying degrees of disaggregation. Relatedly, climate change is increasingly apparent in observations at the local scale, which is challenging the primacy of climate model simulations. Finally, the explosion of climate data is leading to more phenomena-laden methodologies such as machine learning. All this demands a re-think of how attribution is performed and causal explanations are constructed. Here we use Lloyd’s ‘Logic of Research Questions’ framework to show how the way in which the attribution question is framed can strongly constrain its possible and responsive answers. To address the Research Question ‘What was the effect of ACC on X?’ (RQ1), scientists generally consider the question ‘What were the causal factors leading to X, and was ACC among them?’. If the causal factors include only external forcing and internal variability (RQ2), then answering RQ2 also answers RQ1. However, this unconditional attribution is not always possible. In such cases, allowing the causal factors to include elements of the climate system itself (RQ3)—the conditional, storyline approach—is shown to allow for a wider range of possible and responsive answers than RQ2, including that of singular causation. This flexibility is important when uncertainties are high. As a result, the conditional RQ3 mitigates against the sort of epistemic injustice that can arise from the unconditional RQ2.
{"title":"Foundations of attribution in climate-change science","authors":"E. Lloyd, T. Shepherd","doi":"10.1088/2752-5295/aceea1","DOIUrl":"https://doi.org/10.1088/2752-5295/aceea1","url":null,"abstract":"Attribution—the explanation of an observed change in terms of multiple causal factors—is the cornerstone of climate-change science. For anthropogenic climate change (ACC), the central causal factor is evidently ACC itself, and one of the primary tools used to reveal ACC is aggregation, or grouping together, of data, e.g. global mean surface temperature. Whilst this approach has served climate-change science well, the landscape is changing rapidly. First, there is an increasing focus on regional or local aspects of climate change, and on singular or unprecedented events, which require varying degrees of disaggregation. Relatedly, climate change is increasingly apparent in observations at the local scale, which is challenging the primacy of climate model simulations. Finally, the explosion of climate data is leading to more phenomena-laden methodologies such as machine learning. All this demands a re-think of how attribution is performed and causal explanations are constructed. Here we use Lloyd’s ‘Logic of Research Questions’ framework to show how the way in which the attribution question is framed can strongly constrain its possible and responsive answers. To address the Research Question ‘What was the effect of ACC on X?’ (RQ1), scientists generally consider the question ‘What were the causal factors leading to X, and was ACC among them?’. If the causal factors include only external forcing and internal variability (RQ2), then answering RQ2 also answers RQ1. However, this unconditional attribution is not always possible. In such cases, allowing the causal factors to include elements of the climate system itself (RQ3)—the conditional, storyline approach—is shown to allow for a wider range of possible and responsive answers than RQ2, including that of singular causation. This flexibility is important when uncertainties are high. As a result, the conditional RQ3 mitigates against the sort of epistemic injustice that can arise from the unconditional RQ2.","PeriodicalId":432508,"journal":{"name":"Environmental Research: Climate","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129811467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-09DOI: 10.1088/2752-5295/aceea0
Johannes Többen, Peter-Paul Pichler, Ingram S Jaccard, K. Kratena, D. Moran, Heran Zheng, H. Weisz
Carbon pricing is a core climate policy in many countries. However, the distribution of impacts is highly unequal across income brackets, but also across household types and regions. The complex interplay between household characteristics and location specific factors such as building stock and transport infrastructure considerably hampers our understanding of the inequality impacts of carbon taxes and the development of remedial measures. In this paper, we simulate the impacts of carbon taxes and compensation on the purchasing power of more than 38 million German households living in over 11 000 municipalities. We find that the strength of impacts varies more within income groups (horizontal inequality) than across income groups (vertical inequality), based on demographic, socio-economic and geographic factors. Without compensation, a carbon tax of €50 per ton doubles the number of households at risk of becoming energy poor, the majority of them low-income families in remotely located small and medium cities. A lump sum payment of €100 per capita and year reduces inequality impacts and additional energy poverty risk substantially.
{"title":"Unequal carbon tax impacts on 38 million German households: assessing spatial and socio-economic hotspots","authors":"Johannes Többen, Peter-Paul Pichler, Ingram S Jaccard, K. Kratena, D. Moran, Heran Zheng, H. Weisz","doi":"10.1088/2752-5295/aceea0","DOIUrl":"https://doi.org/10.1088/2752-5295/aceea0","url":null,"abstract":"Carbon pricing is a core climate policy in many countries. However, the distribution of impacts is highly unequal across income brackets, but also across household types and regions. The complex interplay between household characteristics and location specific factors such as building stock and transport infrastructure considerably hampers our understanding of the inequality impacts of carbon taxes and the development of remedial measures. In this paper, we simulate the impacts of carbon taxes and compensation on the purchasing power of more than 38 million German households living in over 11 000 municipalities. We find that the strength of impacts varies more within income groups (horizontal inequality) than across income groups (vertical inequality), based on demographic, socio-economic and geographic factors. Without compensation, a carbon tax of €50 per ton doubles the number of households at risk of becoming energy poor, the majority of them low-income families in remotely located small and medium cities. A lump sum payment of €100 per capita and year reduces inequality impacts and additional energy poverty risk substantially.","PeriodicalId":432508,"journal":{"name":"Environmental Research: Climate","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122802895","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-04DOI: 10.1088/2752-5295/aced63
O. Miyawaki, T. Shaw, M. Jansen
The modern Arctic climate during wintertime is characterized by sea-ice cover, a strong surface temperature inversion, and the absence of convection. Correspondingly, the energy balance in the Arctic atmosphere today is dominated by atmospheric radiative cooling and advective heating, so-called radiative advective equilibrium. Climate change in the Arctic involves sea-ice melt, vanishing of the surface inversion, and emergence of convective precipitation. Here we show climate change in the Arctic involves the emergence of a new energy balance regime characterized by radiative cooling, convective heating, and advective heating, so-called radiative convective advective equilibrium. A time-dependent decomposition of the atmospheric energy balance shows the regime transition is associated with enhanced radiative cooling followed by decreased advective heating. The radiative cooling response consists of a robust clear-sky greenhouse effect and a transient cloud contribution that varies across models. Mechanism-denial experiments in an aquaplanet with and without interactive sea ice highlight the important role of sea-ice melt in both the radiative cooling and advective heating responses. The results show that climate change in the Arctic involves temporally evolving mechanisms, suggesting that an emergent constraint based on historical data or trends may not constrain the long-term response.
{"title":"The emergence of a new wintertime Arctic energy balance regime","authors":"O. Miyawaki, T. Shaw, M. Jansen","doi":"10.1088/2752-5295/aced63","DOIUrl":"https://doi.org/10.1088/2752-5295/aced63","url":null,"abstract":"The modern Arctic climate during wintertime is characterized by sea-ice cover, a strong surface temperature inversion, and the absence of convection. Correspondingly, the energy balance in the Arctic atmosphere today is dominated by atmospheric radiative cooling and advective heating, so-called radiative advective equilibrium. Climate change in the Arctic involves sea-ice melt, vanishing of the surface inversion, and emergence of convective precipitation. Here we show climate change in the Arctic involves the emergence of a new energy balance regime characterized by radiative cooling, convective heating, and advective heating, so-called radiative convective advective equilibrium. A time-dependent decomposition of the atmospheric energy balance shows the regime transition is associated with enhanced radiative cooling followed by decreased advective heating. The radiative cooling response consists of a robust clear-sky greenhouse effect and a transient cloud contribution that varies across models. Mechanism-denial experiments in an aquaplanet with and without interactive sea ice highlight the important role of sea-ice melt in both the radiative cooling and advective heating responses. The results show that climate change in the Arctic involves temporally evolving mechanisms, suggesting that an emergent constraint based on historical data or trends may not constrain the long-term response.","PeriodicalId":432508,"journal":{"name":"Environmental Research: Climate","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133992332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-04DOI: 10.1088/2752-5295/aced62
Ed Atkins
[Extract from Introduction] This perspective details how objects and technologies, like the gas stove, are becoming key sites where climate policy is located within broader politically-charged ‘culture wars’. Within this process, climate policies are inscribed with new meanings that position groups against one another. While concerns about gas stoves were linked to public health, they were presented by detractors as representative of climate action. One Fox News article argued that: “These Leftists don't give a damn about everyday Americans… Barking orders is their favorite indoor activity. And if total control buys them a holier spot in Climatarian Heaven, even better.” [2] Whilst gas stove emissions aren’t necessarily significant to fulfilling national emission reductions, any potential regulation will shift domestic energy use – due to the technology being used in close to 40% of US homes [3]. This episode illuminates an emergent shift in the narratives adopted by those opposing climate action. Rather than being primarily sceptical about climate change and mitigation and adaptation policies, political figures are working to link climate action to broader ideological battles about the economy, society, and identity. Within such battles, new objects will become key ‘artefacts’ in the climate change culture wars – becoming infused with new meanings as they emerge or are phased out. These must be understood further as failing to do so can open future environmental and climate policy to backlash, polarisation, and opposition.
{"title":"What next for the climate change culture wars?","authors":"Ed Atkins","doi":"10.1088/2752-5295/aced62","DOIUrl":"https://doi.org/10.1088/2752-5295/aced62","url":null,"abstract":"\u0000 [Extract from Introduction] This perspective details how objects and technologies, like the gas stove, are becoming key sites where climate policy is located within broader politically-charged ‘culture wars’. Within this process, climate policies are inscribed with new meanings that position groups against one another. While concerns about gas stoves were linked to public health, they were presented by detractors as representative of climate action. One Fox News article argued that: “These Leftists don't give a damn about everyday Americans… Barking orders is their favorite indoor activity. And if total control buys them a holier spot in Climatarian Heaven, even better.” [2] Whilst gas stove emissions aren’t necessarily significant to fulfilling national emission reductions, any potential regulation will shift domestic energy use – due to the technology being used in close to 40% of US homes [3]. This episode illuminates an emergent shift in the narratives adopted by those opposing climate action. Rather than being primarily sceptical about climate change and mitigation and adaptation policies, political figures are working to link climate action to broader ideological battles about the economy, society, and identity. Within such battles, new objects will become key ‘artefacts’ in the climate change culture wars – becoming infused with new meanings as they emerge or are phased out. These must be understood further as failing to do so can open future environmental and climate policy to backlash, polarisation, and opposition.","PeriodicalId":432508,"journal":{"name":"Environmental Research: Climate","volume":"57 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133317119","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-04DOI: 10.1088/2752-5295/aced60
Marybeth Arcodia, Elizabeth A. Barnes, Kirsten J. Mayer, Ji-Woo Lee, A. Ordoñez, M. Ahn
Identifying predictable states of the climate system allows for enhanced prediction skill on the generally low-skill subseasonal timescale via forecasts with higher confidence and accuracy, known as forecasts of opportunity. This study takes a neural network approach to explore decadal variability of subseasonal predictability, particularly during forecasts of opportunity. Specifically, this work quantifies subseasonal prediction skill provided by the tropics within the Community Earth System Model Version 2 (CESM2) Large Ensemble and assesses how this skill evolves on decadal timescales. Utilizing the networks’ confidence and explainable artificial intelligence, physically meaningful sources of predictability associated with periods of enhanced skill are identified. Using these networks, we find that tropically-driven subseasonal predictability varies on decadal timescales during forecasts of opportunity. Further, we investigate the drivers of the low frequency modulation of the tropical-extratropical teleconnection and discuss the implications. Analysis is extended to ECMWF Reanalysis v5 data, revealing that the relationships learned within the CESM2-Large Ensemble holds in modern reanalysis data. These results indicate that the neural networks are capable of identifying predictable decadal states of the climate system within CESM2 that are useful for making confident, accurate subseasonal precipitation predictions in the real world.
{"title":"Assessing decadal variability of subseasonal forecasts of opportunity using explainable AI","authors":"Marybeth Arcodia, Elizabeth A. Barnes, Kirsten J. Mayer, Ji-Woo Lee, A. Ordoñez, M. Ahn","doi":"10.1088/2752-5295/aced60","DOIUrl":"https://doi.org/10.1088/2752-5295/aced60","url":null,"abstract":"Identifying predictable states of the climate system allows for enhanced prediction skill on the generally low-skill subseasonal timescale via forecasts with higher confidence and accuracy, known as forecasts of opportunity. This study takes a neural network approach to explore decadal variability of subseasonal predictability, particularly during forecasts of opportunity. Specifically, this work quantifies subseasonal prediction skill provided by the tropics within the Community Earth System Model Version 2 (CESM2) Large Ensemble and assesses how this skill evolves on decadal timescales. Utilizing the networks’ confidence and explainable artificial intelligence, physically meaningful sources of predictability associated with periods of enhanced skill are identified. Using these networks, we find that tropically-driven subseasonal predictability varies on decadal timescales during forecasts of opportunity. Further, we investigate the drivers of the low frequency modulation of the tropical-extratropical teleconnection and discuss the implications. Analysis is extended to ECMWF Reanalysis v5 data, revealing that the relationships learned within the CESM2-Large Ensemble holds in modern reanalysis data. These results indicate that the neural networks are capable of identifying predictable decadal states of the climate system within CESM2 that are useful for making confident, accurate subseasonal precipitation predictions in the real world.","PeriodicalId":432508,"journal":{"name":"Environmental Research: Climate","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123169080","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-08-04DOI: 10.1088/2752-5295/aced61
M. Bushuk, L. Polvani, M. England
The rapid decline of Arctic sea ice is widely believed to be a consequence of increasing atmospheric concentrations of greenhouse gases (GHGs). While carbon dioxide (CO2) is the dominant GHG contributor, recent work has highlighted a substantial role for ozone-depleting substances (ODS) in Arctic sea ice loss. However, a careful analysis of the mechanisms and relative impacts of CO2 versus ODS on Arctic sea ice loss has yet to be performed. This study performs this comparison over the period 1955–2005 when concentrations of ODS increased rapidly, by analyzing a suite of all-but-one-forcing ensembles of climate model integrations, designed to isolate the forced response to individual forcing agents in the context of internal climate variability. We show that ODS have played a significant role in year-round Arctic sea ice extent and volume trends over that period, accounting for 64% and 32% of extent and volume trends, respectively. These impacts represent 50% and 38% of the impact from CO2 forcing, respectively. We find that ODS act via similar physical processes to CO2, causing sea ice loss via increased summer melt, and not sea ice dynamics changes. These findings imply that the future trajectory of ODS emissions will play an important role in future Arctic sea ice evolution.
{"title":"Comparing the impacts of ozone-depleting substances and carbon dioxide on Arctic sea ice loss","authors":"M. Bushuk, L. Polvani, M. England","doi":"10.1088/2752-5295/aced61","DOIUrl":"https://doi.org/10.1088/2752-5295/aced61","url":null,"abstract":"The rapid decline of Arctic sea ice is widely believed to be a consequence of increasing atmospheric concentrations of greenhouse gases (GHGs). While carbon dioxide (CO2) is the dominant GHG contributor, recent work has highlighted a substantial role for ozone-depleting substances (ODS) in Arctic sea ice loss. However, a careful analysis of the mechanisms and relative impacts of CO2 versus ODS on Arctic sea ice loss has yet to be performed. This study performs this comparison over the period 1955–2005 when concentrations of ODS increased rapidly, by analyzing a suite of all-but-one-forcing ensembles of climate model integrations, designed to isolate the forced response to individual forcing agents in the context of internal climate variability. We show that ODS have played a significant role in year-round Arctic sea ice extent and volume trends over that period, accounting for 64% and 32% of extent and volume trends, respectively. These impacts represent 50% and 38% of the impact from CO2 forcing, respectively. We find that ODS act via similar physical processes to CO2, causing sea ice loss via increased summer melt, and not sea ice dynamics changes. These findings imply that the future trajectory of ODS emissions will play an important role in future Arctic sea ice evolution.","PeriodicalId":432508,"journal":{"name":"Environmental Research: Climate","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128958873","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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