Ice algae are critical components to the lipid-driven Arctic marine food web, particularly early in the spring. As little is known about these communities in multiyear ice (MYI), we aimed to provide a baseline of fatty acid (FA) and stable isotope signatures of sea-ice communities in MYI from the Lincoln Sea and compare these biomarkers to first-year ice (FYI). Significant differences in the relative proportions of approximately 25% of the identified FAs and significantly higher nitrogen stable isotope values (δ 15 N) in bottom-ice samples of FYI (δ 15 N = 6.4 ± 0.7%) compared to MYI (δ 15 N = 5.0 ± 0.4%) reflect different community compositions in the two ice types. Yet, the relative proportion of diatom- and dinoflagellate-associated FAs, as well as their bulk and most of the FA-specific carbon stable isotope compositions (δ 13 C) were not significantly different between bottom FYI (bulk δ 13 C: –28.4% to –26.7%, FA average δ 13 C: –34.4% to –31.7%) and MYI (bulk δ 13 C: –27.6% to –27.2%, FA average δ 13 C: –33.6% to –31.9%), suggesting at least partly overlapping community structures and similar biochemical processes within the ice. Diatom-associated FAs contributed, on average, 28% and 25% to the total FA content of bottom FYI and MYI, respectively, indicating that diatoms play a central role in structuring sea-ice communities in the Lincoln Sea. The differences in FA signatures of FYI and MYI support the view that different ice types harbor different inhabitants and that the loss of Arctic MYI will impact complex food web interactions with ice-associated ecosystems. Comparable nutritional quality of FAs, however, as indicated by similar average levels of polyunsaturated FAs in bottom FYI (33%) and MYI (28%), could help to ensure growth and reproduction of ice-associated grazers despite the shift from a MYI to FYI-dominated sea-ice cover with ongoing climate warming.

Benthic organisms depend primarily on seasonal pulses of organic matter from primary producers. In the Arctic, declines in sea ice due to warming climate could lead to changes in this food supply with as yet unknown effects on benthic trophic dynamics. Benthic consumer diets and food web structure were studied in a seasonally ice-covered region of Baffin Bay during spring 2016 at stations ranging in depth from 199 to 2,111 m. We used a novel combination of highly branched isoprenoid (HBI) lipid biomarkers and stable isotope ratios (δ 13 C, δ 15 N) to better understand the relationship between the availability of carbon sources in spring on the seafloor and their assimilation and transfer within the benthic food web. Organic carbon from sea ice (sympagic carbon [SC]) was an important food source for benthic consumers. The lipid biomarker analyses revealed a high relative contribution of SC in sediments (mean SC% ± standard deviation [ SD ] = 86% ± 16.0, n = 17) and in benthic consumer tissues (mean SC% ± SD = 78% ± 19.7, n = 159). We also detected an effect of sea-ice concentration on the relative contribution of SC in sediment and in benthic consumers. Cluster analysis separated the study region into three different zones according to the relative proportions of SC assimilated by benthic macrofauna. We observed variation of the benthic food web between zones, with increases in the width of the ecological niche in zones with less sea-ice concentration, indicating greater diversity of carbon sources assimilated by consumers. In zones with greater sea-ice concentration, the higher availability of SC increased the ecological role that primary consumers play in driving a stronger transfer of nutrients to higher trophic levels. Based on our results, SC is an important energy source for Arctic deep-sea benthos in Baffin Bay, such that changes in spring sea-ice phenology could alter benthic food-web structure.

The ability of the ocean to continue to sustain human society depends on adequate protections of its ecosystem function and services. Despite the establishment of marine protected areas, formal protection of critical connectivity corridors to link habitats and thereby maintain necessary demographic transitions in marine species under threat is now rare. Such protections are critical to future resilience of food webs as climate and ocean change continues. Here, we focus on the Gulf of Mexico to support an integrative, holistic approach to marine and coastal habitat restoration, rehabilitation, and conservation in an ecosystem context following the extensive environmental and living resource injuries from the Deepwater Horizon oil well blowout. Critically important physical, chemical, and biological connectivity processes drive nutrient transport from the nearshore, mid-waters, and even deep ocean into coastal terrestrial habitats, enhancing primary production and terrestrial species populations. The emerging scientific understanding of the nature, habitat specificity, locations, and directions of transport in connectivity processes can help build natural ecosystem capital through protecting flows from land to sea and from the sea to multiple coastal habitats. We expose a dire need for a new conservation imperative, recognizing that oceanic and coastal protected areas established around the reliance of individual species on critical habitats are insufficient without also conserving relevant connectivity corridors that service ontogenetic migration pathways and ecosystem-support processes. Such connectivity must be explicitly understood, protected, and often actively enhanced through restoration intervention to ensure the success of various site-specific conservation actions and be continually modified in anticipation of and in response to multiple impacts of changing climate.

Many ecosystems are experiencing an increase in drought conditions as a consequence of climate warming and changing precipitation patterns. The stress imposed by these environmental changes can affect ecosystem processes such as the extracellular enzymatic degradation of carbon-containing leaf litter by soil microbial communities. However, the magnitude of these impacts may depend on the composition and metabolism of the microbial community. Based on the hypothesis of local adaptation, microbial communities native to warm-dry ecosystems should display a greater capacity to degrade leaf litter polymers with extracellular enzymes following exposure to warm-dry conditions. To test this hypothesis, we performed a microcosm study in which we monitored extracellular enzyme activity and respiration of microbial communities from five ecosystems along a southern California climate gradient, ranging from warmer, drier desert to wetter, cooler subalpine forest. To simulate drought and rewetting, we subjected microcosms to periods of high temperature and low moisture followed by a water pulse. We found that enzyme activity of wet-cool communities generally exceeded that of warm-dry communities across enzyme types for the five sites we considered. Additionally, we observed a significant decrease in respiration for all communities after longer durations of drought exposure. Although these findings did not align with our expectations of local adaptation, they suggest litter-inhabiting microbial communities are able to retain metabolic functioning in environmental conditions different from those of their native ecosystems. These results may imply that factors such as litter chemistry impose greater constraints than climate on community metabolic function. Overall, despite differences in local climates, microbial communities from semiarid regions may be metabolically adapted to maintain functioning in the face of drought.

This study details the enhancement and calibration of the Arctic implementation of the HYdrological Predictions for the Environment (HYPE) hydrological model established for the BaySys group of projects to produce freshwater discharge scenarios for the Hudson Bay Drainage Basin (HBDB). The challenge in producing estimates of freshwater discharge for the HBDB is that it spans over a third of Canada’s continental landmass and is 40% ungauged. Scenarios for BaySys require the separation between human and climate interactions, specifically the separation of regulated river discharge from a natural, climate-driven response. We present three key improvements to the modelling system required to support the identification of natural from anthropogenic impacts: representation of prairie disconnected landscapes (i.e., non-contributing areas), a method to generalize lake storage-discharge parameters across large regions, and frozen soil modifications. Additionally, a unique approach to account for irregular hydrometric gauge density across the basins during model calibration is presented that avoids overfitting parameters to the densely gauged southern regions. We summarize our methodologies used to facilitate improved separation of human and climate driven impacts to streamflow within the basin and outline the baseline discharge simulations used for the BaySys group of projects. Challenges remain for modeling the most northern reaches of the basin, and in the lake-dominated watersheds. The techniques presented in this work, particularly the lake and flow signature clusters, may be applied to other high latitude, ungauged Arctic basins. Discharge simulations are subsequently used as input data for oceanographic, biogeochemical, and ecosystem studies across the HBDB.

Young people are both among the generations to be most affected by climate change and critical advocates for climate action. In the face of growing urgency surrounding the climate crisis, the United Nations Framework Convention on Climate Change (UNFCCC) has become an important institutional framework for political progress. We developed a community-based participatory action research project centered on youth involved in the COP climate negotiations. A “leverage points” approach guided our research; this paper is the first time the framework has been applied in an international negotiations context. Our findings point to the structural power, networks, and paradigms that youth might engage with for international climate justice work. We identify actionable leverage points through which youth organizers might increase their social power in the COP process to bring about climate action. Many of these leverage points are rooted in dynamics of power, which we expand upon and connect to broader literature. Moving forward, these findings can benefit and inform the strategies of youth as they participate in the COP process.

The decline of sea-ice thickness, area, and volume due to the transition from multi-year to first-year sea ice has improved the under-ice light environment for pelagic Arctic ecosystems. One unexpected and direct consequence of this transition, the proliferation of under-ice phytoplankton blooms (UIBs), challenges the paradigm that waters beneath the ice pack harbor little planktonic life. Little is known about the diversity and spatial distribution of UIBs in the Arctic Ocean, or the environmental drivers behind their timing, magnitude, and taxonomic composition. Here, we compiled a unique and comprehensive dataset from seven major research projects in the Arctic Ocean (11 expeditions, covering the spring sea-ice-covered period to summer ice-free conditions) to identify the environmental drivers responsible for initiating and shaping the magnitude and assemblage structure of UIBs. The temporal dynamics behind UIB formation are related to the ways that snow and sea-ice conditions impact the under-ice light field. In particular, the onset of snowmelt significantly increased under-ice light availability (>0.1–0.2 mol photons m –2 d –1 ), marking the concomitant termination of the sea-ice algal bloom and initiation of UIBs. At the pan-Arctic scale, bloom magnitude (expressed as maximum chlorophyll a concentration) was predicted best by winter water Si(OH) 4 and PO 4 3– concentrations, as well as Si(OH) 4 :NO 3 – and PO 4 3– :NO 3 – drawdown ratios, but not NO 3 – concentration. Two main phytoplankton assemblages dominated UIBs (diatoms or Phaeocystis ), driven primarily by the winter nitrate:silicate (NO 3 – :Si(OH) 4 ) ratio and the under-ice light climate. Phaeocystis co-dominated in low Si(OH) 4 (i.e., NO 3 :Si(OH) 4 molar ratios >1) waters, while diatoms contributed the bulk of UIB biomass when Si(OH) 4 was high (i.e., NO 3 :Si(OH) 4 molar ratios <1). The implications of such differences in UIB composition could have important ramifications for Arctic biogeochemical cycles, and ultimately impact carbon flow to higher trophic levels and the deep ocean.

Young people represent a powerful force for social change, and they have an important role to play in climate change responses. However, empowering young people to be “systems changers” is not straightforward. It is particularly challenging within educational systems that prioritize instrumental learning over critical thinking and creative actions. History has shown that by creating novel spaces for reflexivity and experimentation, the arts have played a role in shifting mindsets and opening up new political horizons. In this paper, we explore the role of art as a driver for societal transformation in a changing climate and consider how an experiment with change can facilitate reflection on relationships between individual change and systems change. Following a review of the literature on transformations, transformative learning and the role of art, we describe an experiment with change carried out with students at an Art High School in Lisbon, Portugal, which involved choosing one sustainable behavior and adopting it for 30 days. A transformative program encouraged regular reflection and group discussions. During the experiment, students started developing an art project about his or her experience with change. The results show that a transformative learning approach that engages students with art can support critical thinking and climate change awareness, new perspectives and a sense of empowerment. Experiential, arts-based approaches also have the potential to create direct and indirect effects beyond the involved participants. We conclude that climate-related art projects can serve as more than a form of science communication. They represent a process of opening up imaginative spaces where audiences can move more freely and reconsider the role of humans as responsible beings with agency and a stake in sustainability transformations.

The food sector is a significant contributor to greenhouse gas emissions, contributing 10–32% of global anthropogenic sources. Compared with land-based food production systems, relatively little is known about the climate impact of seafood products. Previous studies have placed an emphasis on fishing activities, overlooking the contribution of the processing phase in the seafood supply chain. Furthermore, other studies have ignored short-lived climate forcing pollutants which can be particularly large for ship fuels. To address these critical knowledge gaps, we conducted a carbon footprint analysis of seafood products from Alaska pollock, one of the world’s largest fisheries. A holistic assessment was made including all components in the supply chain from fishing through retail display case, including a broad suite of climate forcing pollutants (well-mixed greenhouse gases, sulfur oxides, nitrogen oxides, black carbon and organic carbon), for domestic and top importers. We found that in some instances the processing phase contributed nearly twice the climate impact as the fishing phase of the seafood supply chain. For highly fuel-efficient fisheries, such as the Alaska pollock catcher-processor fleet, including the processing phase of the seafood supply chain is essential. Furthermore, the contribution from cooling emissions (sulfur and nitrogen oxides, and organic carbon) offsets a significant portion of the climate forcing from warming emissions. The estimates that include only greenhouse gases are as much as 2.6 times higher than the cases that include short-lived climate forcing pollutants. This study also advances our understanding of the climate impact of seafood distribution with products for the domestic retail market having a climate impact that is as much as 1.6 times higher than export products that undergo transoceanic shipping. A full accounting of the supply chain and of the impact of the pollutants emitted by food production systems is important for climate change mitigation strategies in the near-term.

Over the past three decades, marine resource management has shifted conceptually from top-down sectoral approaches towards the more systems-oriented multi-stakeholder frameworks of integrated coastal management and ecosystem-based conservation. However, the successful implementation of such frameworks is commonly hindered by a lack of cross-disciplinary knowledge transfer, especially between natural and social sciences. This review represents a holistic synthesis of three decades of change in the oceanography, biology and human dimension of False Bay, South Africa. The productivity of marine life in this bay and its close vicinity to the steadily growing metropolis of Cape Town have led to its socio-economic significance throughout history. Considerable research has highlighted shifts driven by climate change, human population growth, serial overfishing, and coastal development. Upwelling-inducing winds have increased in the region, leading to cooling and likely to nutrient enrichment of the bay. Subsequently the distributions of key components of the marine ecosystem have shifted eastward, including kelp, rock lobsters, seabirds, pelagic fish, and several alien invasive species. Increasing sea level and exposure to storm surges contribute to coastal erosion of the sandy shorelines in the bay, causing losses in coastal infrastructure and posing risk to coastal developments. Since the 1980s, the human population of Cape Town has doubled, and with it pollution has amplified. Overfishing has led to drastic declines in the catches of numerous commercially and recreationally targeted fish, and illegal fishing is widespread. The tourism value of the bay contributes substantially to the country’s economy, and whale watching, shark-cage diving and water sports have become important sources of revenue. Compliance with fisheries and environmental regulations would benefit from a systems-oriented approach whereby coastal systems are managed holistically, embracing both social and ecological goals. In this context, we synthesize knowledge and provide recommendations for multidisciplinary research and monitoring to achieve a better balance between developmental and environmental agendas.

Sustainability transitions tend to be seen as technical, not social, affairs. Mainstream scholars and practitioners do not very often acknowledge environmental and social justice in their transitions work. They seldom recognize rights for racially marginalized people, or the possible existence of rights of Earth. Nor do they query whether they are exaggerating the reach of scientific and technological solutions. By contrast, some recent ecological science fiction writing has begun to place these issues at the center of transitions. In the Broken Earth series, N.K. Jemisin explores Earth through the lens of racial and ecological injustice. She interrogates four themes relevant to transitions. How should we live in a climate-changed world? What role does racial and social subordination play in destroying the environment? What are the dangers of hubris in seeking out a fundamental change through science and technology that cannot be readily controlled after all? How should we think about Earth itself? I conclude with some thoughts on how Earth could be made ‘unbroken’ again through integrating recognition, humility, renewal, and redistribution into transitions.

The socio-ecological sensitivity to water deficits makes Chile highly vulnerable to global change. New evidence of a multi-decadal drying trend and the impacts of a persistent drought that since 2010 has affected several regions of the country, reinforce the need for clear diagnoses of the hydro-climate changes in Chile. Based on the analysis of long-term records (50+ years) of precipitation and streamflow, we confirm a tendency toward a dryer condition in central-southern Chile (30–48°S). We describe the geographical and seasonal character of this trend, as well as the associated large-scale circulation patterns. When a large ensemble of climate model simulations is contrasted to observations, anthropogenic forcing appears as the leading factor of precipitation change. In addition to a drying trend driven by greenhouse gas forcing in all seasons, our results indicate that the Antarctic stratospheric ozone depletion has played a major role in the summer rainfall decline. Although average model results agree well with the drying trend’s seasonal character, the observed change magnitude is two to three times larger than that simulated, indicating a potential underestimation of future projections for this region. Under present-day carbon emission rates, the drying pathway in Chile will likely prevail during the next decades, although the summer signal should weaken as a result of the gradual ozone layer recovery. The trends and scenarios shown here pose substantial stress on Chilean society and its institutions, and call for urgent action regarding adaptation measures.

Multilateral efforts are essential to an effective response to climate change, but individual nations define climate action policy by translating local and global objectives into adaptation and mitigation actions. We propose a conceptual framework to explore opportunities for polycentric climate governance, understanding polycentricity as a property that encompasses the potential for coordinating multiple centers of semiautonomous decision-making. We assert that polycentrism engages a diverse array of public and private actors for a more effective approach to reducing the threat of climate change. In this way, polycentrism may provide an appropriate strategy for addressing the many challenges of climate governance in the Anthropocene. We review two Chilean case studies: Chile’s Nationally Determined Contribution on Climate Change and the Chilean National Climate Change Action Plan. Our examination demonstrates that Chile has included a diversity of actors and directed significant financial resources to both processes. The central government coordinated both of these processes, showing the key role of interventions at higher jurisdictional levels in orienting institutional change to improve strategic planning and better address climate change. Both processes also provide some evidence of knowledge co-production, while at the same time remaining primarily driven by state agencies and directed by technical experts. Efforts to overcome governance weaknesses should focus on further strengthening existing practices for climate change responses, establishing new institutions, and promoting decision-making that incorporates diverse social actors and multiple levels of governance. In particular, stronger inclusion of local level actors provides an opportunity to enhance polycentric modes of governance and improve climate change responses. Fully capitalizing on this opportunity requires establishing durable communication channels between different levels of governance.

Fossil fuel divestment activists re-imagine how the war metaphor can be used in climate change action to transform thinking around what will lead to a sustainable society. Through the naming of a clear enemy and an end goal, the overused war metaphor is renewed. By casting the fossil fuel industry in the role of enemy, fossil fuel divestment activists move to a re-imagining of the climate change problem as one that is located in the here and now with known villains who must be challenged and defeated. In this scenario, climate activists move away from the climate and national security framing to a climate and human security way of thinking.

The seasonally ice-covered waters of Hudson Bay, James Bay, Foxe Basin, and Hudson Strait (“the study area”) are bordered by 39 communities with a total population of roughly 50,000 people, most of whom are Inuit or Cree. Sea ice is a cornerstone of the environment and culture of the study area but is also the main barrier to shipping traffic, which has been growing in the area. This paper presents a review of sea ice and shipping in the study area and an analysis of shipping accessibility as represented by the timing of breakup, freeze-up, and the open water season in its offshore and local waters. Offshore ice timing was analyzed using passive microwave-based data for 1980–2014; local ice timing near Rankin Inlet, Churchill, Kuujjuarapik/Whapmagoostui, and Salluit was examined using Canadian Ice Service ice charts for 1996–2016. Open water was defined using sea ice concentration thresholds of ≤15% (offshore) or <20% (local) in an attempt to represent accessible conditions for open water shipping vessels. The results for both offshore and local waters display considerable spatial variability. For offshore waters, breakup currently occurs between 17 May and 19 August and freeze-up occurs between 22 October and 30 December, with overall trends (1980–2014) of +0.58 days year –1 towards an earlier breakup, +0.47 days year –1 towards a later freeze-up, and +0.97 days year –1 towards a longer open water season. Also, significant relationships amongst breakup and freeze-up were observed. For local waters, the 1996–2016 average open water season at the four communities varied between 112.7 days (Churchill) and 154.7 days (Kuujjuarapik/Whapmagoostui). Ultimately, shipping accessibility to Rankin Inlet, Churchill, and Salluit appears to be limited by their local ice timing, while accessibility to Kuujjuarapik/Whapmagoostui appears to be limited by ice timing in northeastern Hudson Bay.

Global climate models were used to assess changes in the mean, variability and extreme sea surface temperatures (SSTs) in northern oceans with a focus on large marine ecosystems (LMEs) adjacent to North America, Europe, and the Arctic Ocean. Results were obtained from 26 models in the Community Model Intercomparison Project Phase 5 (CMIP5) archive and 30 simulations from the National Center for Atmospheric Research Large Ensemble Community Project (CESM-LENS). All of the simulations used the observed greenhouse gas concentrations for 1976–2005 and the RCP8.5 “business as usual” scenario for greenhouse gases through the remainder of the 21 st century. In general, differences between models are substantially larger than among the simulations in the CESM-LENS, indicating that the SST changes are more strongly affected by model formulation than internal climate variability. The annual SST trends over 1976–2099 in the 18 LMEs examined here are all positive ranging from 0.05 to 0.5°C decade –1 . SST changes by the end of the 21 st century are primarily due to a positive shift in the mean with only modest changes in the variability in most LMEs, resulting in a substantial increase in warm extremes and decrease in cold extremes. The shift in the mean is so large that in many regions SSTs during 2070–2099 will always be warmer than the warmest year during 1976–2005. The SST trends are generally stronger in summer than in winter, as greenhouse gas heating is integrated over a much shallower climatological mixed layer depth in summer than in winter, which amplifies the seasonal cycle of SST over the 21 st century. In the Arctic, the mean SST and its variability increases substantially during summer, when it is ice free, but not during winter when a thin layer of ice reforms and SSTs remain near the freezing point.

This study presents the results of a campaign that estimated methane emissions at 268 gas production facilities in the Fayetteville shale gas play using onsite measurements (261 facilities) and two downwind methods – the dual tracer flux ratio method (Tracer Facility Estimate – TFE, 17 facilities) and the EPA Other Test Method 33a (OTM33A Facility Estimate – OFE, 50 facilities). A study onsite estimate (SOE) for each facility was developed by combining direct measurements and simulation of unmeasured emission sources, using operator activity data and emission data from literature. The SOE spans 0–403 kg/h and simulated methane emissions from liquid unloadings account for 88% of total emissions estimated by the SOE, with 76% (95% CI [51%–92%]) contributed by liquid unloading at two facilities. TFE and SOE show overlapping 95% CI between individual estimates at 15 of 16 (94%) facilities where the measurements were paired, while OFE and SOE show overlapping 95% CI between individual estimates at 28 of 43 (65%) facilities. However, variance-weighted least-squares (VWLS) regressions performed on sets of paired estimates indicate statistically significant differences between methods. The SOE represents a lower bound of emissions at facilities where onsite direct measurements of continuously emitting sources are the primary contributor to the SOE, a sub-selection of facilities which minimizes expected inter-method differences for intermittent pneumatic controllers and the impact of episodically-emitting unloadings. At 9 such facilities, VWLS indicates that TFE estimates systematically higher emissions than SOE (TFE-to-SOE ratio = 1.6, 95% CI [1.2 to 2.1]). At 20 such facilities, VWLS indicates that OFE estimates systematically lower emissions than SOE (OFE-to-SOE ratio of 0.41 [0.26 to 0.90]). Given that SOE at these facilities is a lower limit on emissions, these results indicate that OFE is likely a less accurate method than SOE or TFE for this type of facility.

Coordinated dual-tracer, aircraft-based, and direct component-level measurements were made at midstream natural gas gathering and boosting stations in the Fayetteville shale (Arkansas, USA). On-site component-level measurements were combined with engineering estimates to generate comprehensive facility-level methane emission rate estimates (“study on-site estimates (SOE)”) comparable to tracer and aircraft measurements. Combustion slip (unburned fuel entrained in compressor engine exhaust), which was calculated based on 111 recent measurements of representative compressor engines, accounts for an estimated 75% of cumulative SOEs at gathering stations included in comparisons. Measured methane emissions from regenerator vents on glycol dehydrator units were substantially larger than predicted by modelling software; the contribution of dehydrator regenerator vents to the cumulative SOE would increase from 1% to 10% if based on direct measurements. Concurrent measurements at 14 normally-operating facilities show relative agreement between tracer and SOE, but indicate that tracer measurements estimate lower emissions (regression of tracer to SOE = 0.91 (95% CI = 0.83–0.99), R 2 = 0.89). Tracer and SOE 95% confidence intervals overlap at 11/14 facilities. Contemporaneous measurements at six facilities suggest that aircraft measurements estimate higher emissions than SOE. Aircraft and study on-site estimate 95% confidence intervals overlap at 3/6 facilities. The average facility level emission rate (FLER) estimated by tracer measurements in this study is 17–73% higher than a prior national study by Marchese et al.

Decision-support tools are increasingly popular for informing policy decisions linked to environmental issues. For example, a number of decision-support tools on transport planning provide information on expected effects of different measures (actions, policies, or interventions) on air quality, often combined with information on noise pollution or mitigation costs. These tools range in complexity and scale of applicability, from city to international, and include one or several polluting sectors. However, evaluation of the need and utility of tools to support decisions on such linked issues is often lacking, especially for tools intended to support local authorities at the city scale. Here we assessed the need for and value of combining air pollution and climate change mitigation measures into one decision-support tool and the existing policy context in which such a tool might be used. We developed a prototype decision-support tool for evaluating measures for coordinated management of air quality and climate change; and administered a survey in which respondents used the prototype to answer questions about demand for such tools and requirements to make them useful. Additionally, the survey asked questions about participants’ awareness of linkages between air pollution and climate change that are crucial for considering synergies and trade-offs among mitigation measures. Participants showed a high understanding of the linkages between air pollution and climate change, especially recognizing that emissions of greenhouse gases and air pollutants come from the same source. Survey participants were: European, predominantly German; employed across a range of governmental, non-governmental and research organizations; and responsible for a diversity of issues, primarily involving climate change, air pollution or environment. Survey results showed a lack of awareness of decision-support tools and little implementation or regular use. However, respondents expressed a general need for such tools while also recognizing barriers to their implementation, such as limited legal support or lack of time, finances, or manpower. The main barrier identified through this study is the mismatch between detailed information needed from such tools to make them useful at the local implementation scale and the coarser scale information readily available for developing such tools. Significant research efforts at the local scale would be needed to populate decision-support tools with salient mitigation alternatives at the location of implementation. Although global- or regional-scale information can motivate local action towards sustainability, effective on-the-ground implementation of coordinated measures requires knowledge of local circumstances and impacts, calling for active engagement of the local research communities.

Climate change places major transformational demands on modern societies. Transformations require the capacity to collectively envision and meaningfully debate realistic and desirable futures. Without such a collective imagination capacity and active deliberation processes, societies lack both the motivation for change and guidance for decision-making in a certain direction of change. Recent arguments that science fiction can play a role in societal transformation processes is not yet supported by theory or empirical evidence. Advancing the argument that fiction can support sustainability transformations, this paper makes four contributions. First, building on the imaginary concept, I introduce and define the idea of socio-climatic imaginaries. Second, I develop a theory of imagination as linked cognitive-social processes that enable the creation of collectively shared visions of future states of the world. This theory addresses the dynamics that bridge imagination processes in the individual mind and collective imagining that informs social and political decision-making. Third, emphasizing the political nature of creating and contesting imaginaries in a society, I introduce the role of power and agency in this theory of collective imagination. I argue that both ideational and structural power concepts are relevant for understanding the potential societal influence of climate fiction. Finally, the paper illuminates these different forms of transformational power and agency with two brief case studies: two climate fiction novels. I contrast a dystopian and utopian science fiction novel – Paolo Bacigalupi’s The Water Knife ( 2015 ) and Kim Stanley Robinson’s Green Earth (2015). The two books are very similar in their power/agency profile, but the comparison provides initial insights into the different roles of optimistic and pessimistic future visions.