Moisture recycling is a hydrological process that captures the journey of water particles in the atmosphere - starting with terrestrial and oceanic evaporation, continuing with their windborne transport, and ending with precipitation back on land and ocean. Land cover affects the amount of recycled precipitation, and hence the ways we, as humans, use, manage, and govern land concern moisture recycling. Moisture recycling is scarcely managed and governed currently, despite being increasingly recognized as an important process in the biosphere, supporting our society. Moisture recycling is one of the many processes entangling forests and agriculture at various scales, as part of forest-agricultural social-ecological systems. Forests have the potential for securing precipitation for downwind agriculture, although the understanding of this process within the broader forest-agricultural systems remains limited and improving this understanding requires an interdisciplinary approach. As our biophysical understanding of moisture recycling progresses, a question arises: how can we use the knowledge of moisture recycling to guide our activities on land that safeguard forests and agriculture synergistically? The thesis attempts to answer this question by applying a social-ecological systems perspective and an interdisciplinary approach to investigate the interdependence between forests and agriculture through moisture recycling. By applying the forest-agricultural systems context and beyond, the thesis further assesses the need to govern moisture recycling as a mediating process in social-ecological systems. Five papers in this thesis cover different scales of social-ecological processes entangling forests and agriculture. Paper I analyzes moisture recycling at the national scale, to conceptualize its interconnection with forests, agricultural production, and crop trade across countries globally. Paper II focuses on the regional scale dynamics of moisture recycling and the role of forests as moisture sources during heatwaves in Europe. Paper III zooms in on the local scale to detect changes in local forests and shifting cultivation practices as a result of social-ecological pressures on land in the Democratic Republic of Congo. Paper IV complements Paper III with an investigation into the moisture recycling process connecting local forests with local agricultural practices. Finally, Paper V uses a futuring exercise to imagine the governance of moisture recycling as economic goods at diverse scales. Together, these papers suggest that forests support downwind agricultural production through the provision of precipitation within and across scales. This relationship is reciprocal, considering that forests are also influenced by the state of downwind agriculture through social dynamics. Accordingly, moisture recycling unravels a new way of interdependence between forests and agriculture. This thesis advances the moisture recycling knowledge beyond its biophysical aspects, and prompts us to reflect on what governing moisture recycling in the future would entail.

Anomalous precipitation patterns associated with climate change increasingly threaten global crop supply. Forests, as major moisture source, could potentially buffer these risks, yet their specific role in sustaining agriculture and global crop supply remains underexplored. We investigate global forests’ contribution to crop production and export by estimating moisture flows from forests to agricultural areas and pairing them with traded crop flows. We find that agricultural areas in 155 countries rely on transboundary forests for up to 40% of annual precipitation, whereas in 105 countries, as much as 18% of precipitation is recycled from forests nationally. Moisture from forests globally supports 18% of crop production and 30% of crop export studied. We show that crop producers, exporters and importers are directly and indirectly dependent on upwind forested countries through three typologies. Our study implies that strategically conserving forests located upwind of agricultural areas could be leveraged to safeguard global crop supply.

Marine bioprospecting, which involves the exploration of genetic and biochemical material from marine organisms, can be used towards addressing a broad range of public and environmental health applications such as disease treatment, diagnostics and bioremediation. Marine genetic resources are important reservoirs for such bioprospecting efforts; however, the extent to which they are used commercially for natural product discovery and the marine sources from which they are derived are not well understood. Here we introduce a comprehensive database of marine genes referenced in patent filings, the Marine Bioprospecting Patent database. It includes 92,550 protein-coding sequences associated with 4,779 patent filings, identified by analysing all relevant records from genetic sequence databases. Three companies alone—BASF, IFF and DuPont—included sequences from 949 species (more than half of referenced species with identified marine origin). Microbial life in the deep sea, a vast and remote biome predominantly beyond national jurisdiction, is already attracting substantial economic interest; the top ten patent holders have all filed marine gene patents referencing sequences from deep-sea life. Our findings provide an updated understanding of the marine bioprospecting landscape, contribute to the sustainable use of marine biodiversity and underscore the need for policymakers to ensure stewardship of deep-sea ecosystems.

Despite their importance, wetland ecosystems protected by the Ramsar Convention are under pressure from climate change and human activities. These drivers are altering water availability in these wetlands, changing water levels or surface water extent, in some cases, beyond historical variability. Attribution of the effects of human and climate activities is usually focused on changes within the wetlands or their upstream surface and groundwater inputs. However, the reliance of wetland water availability on upwind atmospheric moisture supply is less understood. Here, we assess the vulnerability of 40 Ramsar wetlands to precipitation changes caused by land use and hydroclimatic change occurring in their upwind moisture-supplying regions. We use moisture flows from a Lagrangian tracking model, atmospheric reanalysis data, and historical land use change (LUC) data to assess and quantify these changes. Our analyses show that historical LUC has decreased precipitation and terrestrial moisture recycling in most wetland hydrological basins, decreasing surface water availability (precipitation minus evaporation). The most substantial effects on wetland water availability occurred in the tropic subtropical regions of Central Europe and Asia. Overall, we found wetlands in Central Asia and South America to be the most vulnerable by a combination of LUC-driven effects on runoff, high terrestrial precipitation recycling, and recent decreases in surface water availability. This study stresses the need to incorporate upwind effects of land use changes in the restoration, management, and conservation of the world's wetlands.

We bring together two decades of research on cross-scale spatial and temporal connectivity of water in the Anthropocene to understand the implications for institutional fit and water governance, with a focus on river basin organizations and watershed-based bodies. There is strong evidence showing how hydrological cycles are tightly coupled across larger spatial scales than they were in the past, which implies a possible expansion of the boundaries typically considered in the study and governance of water. Temporally, frequent time lags between action and consequence and the potential for increasing concurrence of extreme events pose risks for decision-makers trying to make accurate and appropriate decisions. Both cross-scale spatial and temporal connectivity create new challenges to key principles regarding participation, deliberation and collaboration in water governance. We argue for a shift from emphasizing how governance can ‘fit’ a closed, biophysical boundary towards a stronger consideration of institutional ‘fitness’ through flexibility, responsiveness and anticipatory capacity to better support water resilience and sustainability.

Non-Technical Summary. Human societies are changing where and how water flows through the atmosphere. However, these changes in the atmospheric water cycle are not being managed, nor is there any real sense of where these changes might be headed in the future. Thus, we develop a new economic theory of atmospheric water management, and explore this theory using creative story-based scenarios. These scenarios reveal surprising possibilities for the future of atmospheric water management, ranging from a stock market for transpiration to on-demand weather. We discuss these story-based futures in the context of research and policy priorities in the present day.

Technical Summary. Humanity is modifying the atmospheric water cycle, via land use, climate change, air pollution, and weather modification. Historically, atmospheric water was implicitly considered a ‘public good’ since it was neither actively consumed nor controlled. However, given anthropogenic changes, atmospheric water can become a ‘common-pool’ good (consumable) or a ‘club’ good (controllable). Moreover, advancements in weather modification presage water becoming a ‘private’ good, meaning both consumable and controllable. Given the implications, we designed a theoretical framing of atmospheric water as an economic good and used a combination of methods in order to explore possible future scenarios based on human modifications of the atmospheric water cycle. First, a systematic literature search of scholarly abstracts was used in a computational text analysis. Second, the output of the text analysis was matched to different parts of an existing economic goods framework. Then, a group of global water experts were trained and developed story-based scenarios. The resultant scenarios serve as creative investigations of the future of human modification of the atmospheric water cycle. We discuss how the scenarios can enhance anticipatory capacity in the context of both future research frontiers and potential policy pathways including transboundary governance, finance, and resource management.

Social Media Summary. Story-based scenarios reveal novel future pathways for the management of the atmospheric water cycle.

Academia has experienced acceleration and expansion in parallel with the Great Acceleration, which has shaped the Anthropocene. Among other pressures, the expectation to be internationally mobile conflicts with many values held by sustainability scholars and results in disillusionment. The changes in the academic system can be seen through the framework of the adaptive cycle, which can help us understand historical parallels and shape the system to better align with sustainability values in future. We hope this piece can contribute to the discussion of the next steps forward to reimagine academia.

Tree restoration is an effective way to store atmospheric carbon and mitigate climate change. However, large-scale tree-cover expansion has long been known to increase evaporation, leading to reduced local water availability and streamflow. More recent studies suggest that increased precipitation, through enhanced atmospheric moisture recycling, can offset this effect. Here we calculate how 900 million hectares of global tree restoration would impact evaporation and precipitation using an ensemble of data-driven Budyko models and the UTrack moisture recycling dataset. We show that the combined effects of directly enhanced evaporation and indirectly enhanced precipitation create complex patterns of shifting water availability. Large-scale tree-cover expansion can increase water availability by up to 6% in some regions, while decreasing it by up to 38% in others. There is a divergent impact on large river basins: some rivers could lose 6% of their streamflow due to enhanced evaporation, while for other rivers, the greater evaporation is counterbalanced by more moisture recycling. Several so-called hot spots for forest restoration could lose water, including regions that are already facing water scarcity today. Tree restoration significantly shifts terrestrial water fluxes, and we emphasize that future tree-restoration strategies should consider these hydrological effects.

The global hydrological cycle is characterized by complex interdependencies and self-regulating feedbacks that keep water in an ever-evolving state of flux at local, regional, and global levels. Increasingly, the scale of human impacts in the Anthropocene is altering the dynamics of this cycle, which presents additional challenges for water governance. Earth system law provides an important approach for addressing gaps in governance that arise from the mismatch between the global hydrological cycle and dispersed regulatory architecture across institutions and geographic regions. In this article, we articulate the potential for Earth system law to account for core hydrological problems that complicate water governance, including delay, redistribution, intertwinements, permanence, and scale. Through merging concepts from Earth system law with existing policy and legal principles, we frame an approach for addressing hydrological problems in the Anthropocene and strengthening institutional fit between established governance systems and the global hydrological cycle. We discuss how such an approach can be applied, and the challenges and implications for governing water as a cycle and complex social-hydrological system, both in research and practice.