Ambio’s legacy on monitoring,impact, and management of acid rain: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Acidification

Early studies published in Ambio showed large-scale acidification of lakes in southern Sweden and Norway from acid rain. These studies were important for delimiting various scientific issues and thus for eventually contributing to legislation, which reduced emissions of sulfur dioxide and nitrogen oxides and helped to mitigate this major environmental problem. Long-term studies and monitoring in Sweden and Norway and at Hubbard Brook Experimental Forest in New Hampshire helped guide this legislation in Europe and in the USA.     

People and biodiversity in the 21st century: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Biodiversity conservation

Fifty years have elapsed since the first publication of Ambio. Throughout this period, fundamental changes have occurred in societal attitudes to biodiversity conservation. Ambio has published numerous papers that have aligned with these new approaches. High citations numbers suggest that Ambio papers have had a significant impact on conservation strategies. We review these publications and find that they align well with changed societal perspectives on biodiversity. Ambio papers have called for greater contributions of local and indigenous peoples and for conservation in multi-functional landscapes. The 1992 Convention on Biological Diversity built on these principles. Negotiations are now underway for a post-2020 framework for biodiversity. Ambio papers have argued for a stronger scientific basis for conservation and for the need to adapt to changing conditions and to the rich diversity of societal preferences for conservation. International processes favor simple, generalizable approaches to conservation but we call for recognition of the diversity of ecological and human conditions in which conservation occurs. There is a need to build capacity to support a diversity of conservation approaches that are adapted to changing local conditions and to the priorities of diverse human societies.     

Solutions-oriented research for sustainability: Turning knowledge into action: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Solutions-oriented research

In this perspective, we reflect upon the question: what processes may help transition scientific insights on sustainability issues into practice and thus contribute to tackling the complex, systemic sustainability problems of today? We use five forerunners in the field of providing and brokering knowledge for science informed real world solutions, all published in Ambio and highlighted in this Anniversary collection, as our starting point. We discuss how the authors present solutions, whom they tried to reach, and what was suggested—implicitly or explicitly—as the potential uptake processes for turning scientific knowledge into practice. With this as the starting point, we discuss how sustainability science, as a field vowed to action, has evolved in its views of actors, pathways for impacts, and the potential roles of research and researchers to promote sustainability transformations.     

Risks to the stratospheric ozone shield in the Anthropocene: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Ozone Layer

Crutzen (1974) and Crutzen and Ehhalt (1977) presented two key papers in Ambio that in Ambioexemplify how science first revealed to humankind the potential for damage to our ozone shield in the Anthropocene. Crutzen’s (1974) review is a sweeping summary of the risks to the ozone layer from supersonic aircraft, chlorofluorocarbons, as well as nuclear weapons testing and nuclear war. Crutzen and Ehhalt (1977) described how the nitrous oxide produced from fertilizers could pose another threat to the stability of the stratospheric ozone layer. The two papers are part of a body of influential scientific work that led to the pioneering Montreal Protocol to Protect the Earth’s Ozone Layer to phase out production of chlorofluorocarbons (in 1987), as well as national decisions that slowed or stopped production of supersonic planes (in the 1970s). They remain guideposts today for ongoing international negotiations regarding reducing emissions from fertilizer and limiting nuclear testing.     

Continuous integration in urban social-ecological systems science needs to allow for spacing co-existence: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Urbanization

Urbanization brings benefits and burdens to both humans and nature. Cities are key systems for integrated social-ecological research and the interdisciplinary journal of Ambio has published ground-breaking contributions in this field. This reflection piece identifies and discusses integration of the human and natural spheres in urban social-ecological research using the following foundational papers as important milestones: Folke et al. (1997), Ernstson et al. (2010) and Andersson et al. (2014). These papers each take unique approaches that aim to uncover core properties—processes, structures, and actors—of urban systems and set them into mutual relationship. This piece will end with a forward-looking vision for the coming 50 years of urban sustainability and resilience study in Ambio.     

Reflecting on the Anthropocene: The Call for Deeper Transformations: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Anthropocene

Research on global environmental change has transformed the way that we think about human-environment relationships and Earth system processes. The four Ambio articles highlighted in this 50th Anniversary Issue have influenced the cultural narrative on environmental change, highlighting concepts such as “resilience,” “coupled human and natural systems”, and the “Anthropocene.” In this peer response, I argue that global change research is still paying insufficient attention to how to deliberately transform systems and cultures to avoid the risks that science itself has warned us about. In particular, global change research has failed to adequately integrate the subjective realm of meaning making into both understanding and action. Although this has been an implicit subtext in global change research, it is time to fully integrate research from the social sciences and environmental humanities.     

Urban sustainability science: prospects for innovations through a system’s perspective,relational and transformations’ approaches: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Urbanization

In this perspective, we present how three initial landmark papers on urban sustainability research contributed to the larger sustainability science scholarship and paved the way for the continued development of urban sustainability research. Based on this, we propose three conceptual innovation pathways to trace the progression of urban sustainability science: First, urban sustainability from a system’s perspective, meaning that urban sustainability requires integrative solutions to work in the tripled social-ecological-technological system setting. Second, urban sustainability from a (people and place) relational perspective, meaning urban sustainability is a contested and dynamic social-ecological contract of cities. As a governance mission, urban sustainability requires evidence from research that can inform coordinated action to bridge people, places, meanings, visions and ecosystems. Third, urban sustainability from a transformative science perspective, meaning that for urban sustainability to be achieved and progressed, deep transformations are required in systems, relations, policies and governance approaches. Our proposal for the future of urban sustainability science centres on emphasizing the relevance and policy applicability of systems’ thinking, value and place thinking and transitions/transformations thinking as fundamental to how knowledge is co-produced by research science, policy and society and becomes actionable.     

Revisiting old lessons from classic literature on persistent global pollutants: This article belongs to Ambio’s 50th Anniversary Collection. Theme: Environmental contaminants

Looking back 50 years at classic literature was a reminder of inspiring discoveries and clever theories that were formative to the field of environmental chemistry, but also of the irreparable costs that persistent global pollutants have had on ecosystems and human society. In my view, these three papers have greatly impacted contemporary science and influenced development of policies that have limited the spread of hazardous contaminants. At the same time, a sobering reality is that reversing decades of past pollution has proven impossible in our lifetime, and global trends are dire for both legacy and emerging contaminants. Lessons in these papers are clear to most environmental scientists, but I argue have not resulted in adequate investment in infrastructure or manpower to enable systematic unbiased searching for pollutants as proposed by Sören Jensen in 1972. Acknowledging that the costs of new global contaminants will be too high, we must incentivize safer chemicals and their sustainable use, increase international exchange of lists of chemicals in commerce, and coordinate international efforts in nontarget screening to identify new contaminants before they circulate the world.