The climate crisis requires nations to achieve human well-being with low national levels of carbon emissions. Countries vary from one another dramatically in how effectively they convert resources into well-being, and some nations with low levels of emissions have relatively high objective and subjective well-being. We identify urgent research and policy agendas for four groups of countries with either low or high emissions and well-being indicators. Least studied are those with low well-being and high emissions. Understanding social and political barriers to switching from high-carbon to lower-carbon modes of production and consumption, and ways to overcome them, will be fundamental.

Advancing solar geoengineering research is associated with multiple hidden injustices that are revealed by addressing three questions: Who is conducting and funding solar geoengineering research? How do those advocating for solar geoengineering research think about social justice and social change? How is this technology likely to be deployed? Navigating these questions reveals that solar geoengineering research is being advocated for by a small group of primarily white men at elite institutions in the Global North, funded largely by billionaires or their philanthropic arms, who are increasingly adopting militarized approaches and logics. Solar geoengineering research advances an extreme, expert–elite technocratic intervention into the global climate system that would serve to further concentrate contemporary forms of political and economic power. For these reasons, we argue that it is unethical and unjust to advance solar geoengineering research.

Biodiversity footprinting links consumers to the biodiversity pressure their consumption induces, thereby informing choices and enabling participation in remediation measures. In order for countries, cities and households to reduce their impacts it is useful to know more precisely what the various drivers of their footprints are. Here we ask: do urban or rural areas in Europe exert higher biodiversity footprints? And how strongly coupled are income and biodiversity losses? Studying urban versus rural households at the country level in Europe, we found both have generally similar footprints, but that higher income households clearly drive higher footprints.

Sustainable access to outer space is increasingly threatened by growing orbital clouds of satellites and debris. A boom in competitively priced commercial rocket launches has lowered prices, prompting satellite operators to begin deploying thousands of satellites. Six decades ago, ‘hard law’ international treaties established governance for outer space designed for the few governmental space programmes. Today, non-governmental commercial entities are operating under voluntary ‘soft law’ rules of the road that expose the deficiencies of the original treaties to empower regulatory supervision of the expanding commercial orbital presence. This paper suggests how a ‘sustainable’ system of governance, required for sustainable space access and exploration, may be promoted by increasing the costs of non-compliance.

Since the earliest stages of international climate policy, carbon dioxide (CO2) has been framed and widely accepted as a problem that needs to be solved by reducing its amount in the atmosphere. In principle this is a correct and relevant starting point for efforts to decarbonize societies. At the same time, however, the unquestioned and one-sided framing of CO2 as a problem has significantly biased the strategies for tackling climate change. We introduce the origins, meanings and implications of one-sided framing of CO2 in climate policy. We also discuss how alternative framings could impact policymaking and eventually our capacity to mitigate climate change. We introduce a paradox: framing CO2 as a problem often translates into policies that hamper the implementation of technologies to decrease the amount of CO2 emitted into the atmosphere. We suggest that plurality in framing CO2 could lead to innovative ways and strategies to combat climate change.

The world agreed to achieve 17 Sustainable Development Goals by 2030. Nine planetary boundaries set an upper limit to Earth system impacts of human activity in the long run. Conventional efforts to achieve the 14 socio-economic goals will raise pressure on planetary boundaries, moving the world away from the three environmental SDGs. We have created a simple model, Earth3, to measure how much environmental damage follows from achievement of the 14 socio-economic goals, and we propose an index to track effects on people's wellbeing. Extraordinary efforts will be needed to achieve all SDGs within planetary boundaries.

The politics of the United Nations aims at sustainable development (i.e., development that can continue with future generations). Andreas Losch has recently proposed to expand our current notion of sustainability to what he calls ‘planetary sustainability’, and he has urged an ethics of planetary sustainability. This comment article discusses these proposals. The proposed conceptual change is assessed, drawing on desiderata suggested by Carnap. To the extent to which the current notion of sustainability has excluded consideration of outer space, we gain in simplicity. To the extent to which it has been unclear about this issue, we gain in exactness. The proposed concept is fruitful because it points to important considerations, in particular if there are extra-terrestrial beings that share moral status with human beings. But to some extent this fruitfulness requires a clear deviation from the anthropocentric outlook of our current notion of sustainability, and costs regarding similarity arise. As far as an ethics of sustainability is concerned, we certainly need to address ethical issues that arise in relation to outer space. However, the notion of planetary sustainability is not likely to figure prominently in related thoughts because the notion of sustainability is not a key concept in known ethical theories.

Individual organisms on land and in the ocean sequester massive amounts of the carbon emitted into the atmosphere by humans. Yet the role of ecosystems as a whole in modulating this uptake of carbon is less clear. Here, we study several different mechanisms by which climate change and ecosystems could interact. We show that climate change could cause changes in ecosystems that reduce their capacity to take up carbon, further accelerating climate change. More research on – and better governance of – interactions between climate change and ecosystems is urgently required.

This perspective article from the co-chairs of the United Nations Environment Programme's Sixth Global Environment Outlook (GEO-6) uses the assessment of the literature in the GEO-6 to show how a healthy planet and healthy people are linked together. It argues that the health of the planet is deteriorating and that this deteriorating ecosystem health has major direct and indirect impacts on human health and well-being. Direct impacts include the impacts of polluted air on the lungs of people, while indirect impacts include the impacts of land degradation on food security. Therefore, protecting the environment will also have major benefits for human health and well-being.

There are significant challenges to retaining indigenous biodiversity and ecological infrastructure in African cities. These include a lack of formal protection and status for remnant ecologically functional patches rendering them open to ad hoc human settlement, which is in part linked to weak governance and management emerging from complex histories, and competing crisis-ridden demands. Persistent gaps in knowledge and practice mean that the social, economic, development and well-being benefits of ecological infrastructure are not understood or demonstrated. Addressing these challenges requires the adoption of multiple top-down government interventions and bottom-up community and neighbourhood actions. The development of detailed case studies that engage with knowledge generation and sharing at multiple scales through co-learning practices will also help create a much-needed deeper understanding of development options within this context.

The UN Sustainable Development Goals (SDGs) and targets are an important achievement. They largely reflect the worldview of Modernity, with its emphasis on scientific and planning rationality and emancipatory ideals. This worldview is no longer evident and dominant, and it is time to systematically explore complementing worldviews. Explicit use of worldviews, as sets of values and beliefs, and ethics enriches the interpretation and implementation of the SDGs. This facilitates the engagement of citizens in their real-world diversity and the development of respect for and empathy and cooperation with people holding other values, beliefs and morals. Dialogue around ‘the middle road’ can give guidance to just, fair and sustainable development pathways.

Mining regions are affected by climate change. Supplies of energy and water are required, and operations become hazardous during adverse weather events. Adapting to climate change takes three forms: incrementally improving the resilience of mining operations; transitioning to more inclusive governance through institutional and policy innovations; and more profound transformations that shift the balance of power, including profit-sharing, localized control or cessation of mining entirely. Clarifying adaptation pathways helps to identify priorities and inform policies for a fairer and more sustainable future for mining and the regions where it takes place.

Projections of a burgeoning population coupled with global environmental change offer an increasingly dire picture of the state of the world's food security in the not-too-distant future. But how can we transform the current food system to become more sustainable, more equitable and more just? We identify kitchens as sites of transformative innovation in the food system where cooks and chefs can leverage traditional food knowledge about local food species to create delicious and nutritious dishes. Achieving a sustainable food system is a grand challenge, one where cooks in particular are stepping forward as innovators to find solutions.

Although the concept of sustainable development is widely used as a guiding principle, there is much less consensus on its normative foundation and ethical implications. Since the 1880s, when social tensions threatened to tear apart European societies during the Industrial Revolution, Catholic social teaching (CST) has served as a sound basis for dialogue for many political leaders regardless of national or religious affiliation. This article examines how Pope Francis’ present-day CST might foster a cross-cultural debate on the ethics of economic growth, social and ecological justice and civil participation on Planet Earth as well as in outer space.

Digitalization coevolves with and fosters three revolutions in urban transport: sharing, electrification and automatization. This dynamic poses severe risks for social and environmental sustainability. Only strong public policies can steer digitalization towards fostering sustainability in urban transport.

Implementing the logical and ontological principles (dualism, mechanicism, reductionism, law of excluded middle, etc.) of modernity has brought forth an unsustainable world. An overcoming of these principles is proposed by mesology (Umweltlehre, fûdoron), centring on the concept of trajection and the existential operator as (als, en tant que).

Most of the water humans consume is for agriculture. Rapidly increasing water demand has led to overexploitation of water resources in many important food-producing regions. In particular, growing groundwater-based irrigation causes potentially damaging depletion. Food systems are increasingly globalized, leading to large export-oriented production. Much research has focused on quantifying the amount of water resources embedded in traded products, but less attention has been given to the role of groundwater use and the related sustainability of agriculture globally. We assess current knowledge of virtual water trade in light of groundwater use and sustainability and highlight remaining challenges in this field.

Sixty years of space activities have led to ongoing scientific and technological progress. Space 4.0 reflects the rapid changes of the space community. Growing interest in space activities leads to increasing participation of numerous new actors in this field. Governments, private actors and international organizations are eager to fill existing gaps in securing global society's needs. The European Space Agency's Space 4.0 concept is designed to host a new era of space activities, aiming to resolve global challenges and to serve society. Space 4.0 developments are highly important, but are taking place in an extremely complex net of legal, regulatory and political considerations. This paper focuses on the legal challenges raised by the new era of Space 4.0 in a sustainability context.

We present a view on global marine fisheries that emphasizes mitigating the conflict between sustainability and the scale of industrial exploitation driven by the demand of continuous economic growth. We then summarize the current state of global fisheries. Finally, we advocate strongly for scaling back industrial fisheries, most of which are non-sustainable. This can be achieved through eliminating the harmful, capacity-enhancing subsidies that prop up industrial fisheries to continue operating despite declining fish stocks. Instead, we propose to support well-managed, locally owned and operated small-scale fisheries, which generally contribute more to local employment and food security. We stress that contrary to deep-seated opinion in the fishing industry and among politicians, reducing overfishing by eliminating overcapacity in fishing fleets will actually lead to greater, not reduced catches. This would address part of the increased global seafood demand over the coming decades, which is driven by population and wealth growth. This seems counterintuitive, but is supported by fisheries science, data and experiences. Thankfully, we are beginning to see that some of these changes are being pursued by a growing number of countries and international institutions.