We are entering a new dimension of the Anthropocene age affecting the Earth and its vital biogeochemical cycles in an unprecedented way. The anthropogenically-produced mass (including plastics, titanium dioxide (TiO2), and ultrafine-soot particles) had surpassed all global living biomass with annual fluxes entering the environment estimated at millions of tons. These anthropogenic particles integrate oceans and interact with the biogeochemical cycles, from microscale to nanoscale (or colloidal scale). The main goal of NANO-GATE is to characterize the presence and the biogeochemical cycling of anthropogenic nanoparticles in the Arctic Ocean. Nanoplastics, TiO2, and nano-soots are targeted due to their extensive use in anthropogenic activities, high reactivity against other contaminants in the environment, and expected ubiquity in the AO. Despite its relatively small size and lower direct contact with human activities, the Arctic Ocean (AO) is one of the most exposed oceans to anthropogenic impacts. While the presence of microscale anthropogenic particles starts to be partially documented there is absolutely no data concerning nanoparticles. And yet, even at (ultra)-trace concentration, and due to their high surface specificity, diffusivity and reactivity, nanoparticles are more likely to interact with biota, especially primary producers, and to impact the main biogeochemical cycles. In light of these properties and the increase in anthropogenic material mass entering the global ocean, there is an urgent need to address the pervasiveness of ANP dispersal, particularly in the AO. NANO-GATE will pioneer ANP research in the AO by providing a unique dataset of their distribution and cycling, with the determination of their behavior with key variables specific to the AO. NANO-GATE will provide unprecedented data to support the various Arctic monitoring program agencies and policymakers and list ANPs as an emerging threat.

We propose to characterize the response of continental biosphere to large extraterrestrial impact craters, in particular the megafires they may have generated, associated with the melting of the Earth surface. Studying the impact glasses ejected at long distance, called tektite, will be instrumental in the project. Three tektite producing impacts occurring on forested tropical surfaces from Nicaragua, Ghana, and Indochina during the last 1.1 Myr will be investigated. Environmental response to impact, probed by pollen, charcoal and other proxies will be studied in various marine and lacustrine archives. Reaction of impact melt with biomass (elements such as C, P, S) will be traced using compositional variability of tektites explored in a systematic way, as well as nano-scale characterization of inclusions in tektites such as phosphates, metal, iron oxydes, and eventual carbon phases. This will bring new clues on tektite production processes and response of ecosystems to megafires.

The D2LIFE project aims to understand the interactions between organic matter and phosphates during the hydrothermal liquefaction of residual biomass (e.g. digestate, sewage sludge, manure, agro-waste). This knowledge will contribute to the development of a hydrothermal treatment process that integrates the recovery of phosphorus (P) with the production of bio-fuels, by concentrating P in a solid phase mainly composed of Ca phosphates which will be used as fertilizer. The objective of the project is to identify and describe the effect of the main operating parameters of the hydrothermal process (e.g. temperature, pressure, reaction time, addition of reagents) on the kinetics and pathways of P conversion, and on the partition of P among the aqueous, oily and solid phases resulting from biomass liquefaction. The methodological approach of the project is based on hydrothermal liquefaction experiments carried out in a batch reactor using a real substrate (digestate from anaerobic digestion of sewage sludge), followed by modeling of the experimental results. The aqueous, oily and solid phases resulting from digestate liquefaction will be separated and characterized in order to quantify the main forms of P (organic and inorganic). The results will allow to identify the effect of the main operating parameters of the hydrothermal process on the conversion pathways and on the partition of P among the different phases, and finally to develop a model that describes P conversion during hydrothermal liquefaction of digestate. Finally, a techno-economic analysis of the process will be carried out to identify the optimal operating parameters based on exergetic criteria, conversion yields, and by-products (Ca phosphates and bio-fuels) recovery performance. The results of the D2LIFE project will have an impact in the field of bio-waste and residual biomass management, and will contribute to the development of a sustainable process chain for the valorization of digestate.

This project aims to generate major breakthroughs in the quantification of ecosystem services provided by biodiversity in agro-ecosystems in the lower Mekong basin, a region facing dramatic environmental and societal changes. In this region, paddy fields appear as mosaics owing to the presence of mounds built by termites. While these structures seem comparable to hedgerows or bocage areas in temperate ecosystems, their impacts on the sustainability of agricultural systems and the livelihood of farmers remain unknown. Therefore, ECO-TERM project proposes to characterize and quantify the ecological (e.g., impact on animal and plant biodiversity), environmental (e.g., impact on soil and water dynamic, pesticide utilization, rice resistance and production) as well as socio-economical processes (e.g., impact on food security, human health, and farmer’s incomes) impacted by these patches of biodiversity and fertility in Cambodia, in adequacy with the axis 1.6 and the Sustainable Development Goals n°1, 2, 3, 8, 12, 13, 15 and 17. This project is built around 3 inter-connected scientific work packages (WPs) and on a WP dedicated to the coordination of cross-cutting activities and the co-construction of knowledge by making farmers and scientists interact within participatory workshops. This project brings together 5 French academic partners and self-funded research units in Cambodia, one local NGO, and one society specialized in the utilization of participatory modelling and role playing games. It requires the recruitment of a PhD student, with transversal activities between WP, and a postdoc for two years (only one year requested to ANR) for the construction of econometric models.

Pacific atolls are at the forefront of debates about effects of global warming and sea-level rise. The resilience capacities of atoll-dwelling populations often dominate discussions although with none or very little consideration for the long history of human occupation and adaptation to the hostile and restricting environmental conditions of these peculiar islands. To shed light on such complex processes, the PASTAtolls project offers a multidisciplinary and multifocal approach of atolls’ socio-ecosystems in Central-East Polynesia (today’s French Polynesia) over the long term. While the ecology of Polynesian atolls is well documented, dedicated Human and Social Sciences (SHS) research remains rare and heterogenous. The atolls’ societies have long been considered unable to achieve social complexity due to the supposedly constraining environments. Such environmental determinism was recently challenged thanks to archaeological and anthropological studies mostly led by members of our team. However, our knowledge on relationships and dynamics between humans and atolls is by far too incomplete. Our project aims at filling this gap by apprehending the unique lifeways of atoll-dwelling populations, both past and present, at a time when they are facing new challenges, especially climate changes. The project is fourfold: 1. Refining the chronology of geological history and human occupation on the Polynesian atolls; 2. Documenting the timing and processes of plants and animals’ introductions and their impact on ecosystems; 3. Reconstructing traditional knowledge and technical know-how now threatened of disappearance; 4. Examining symbolic representations of atolls environments through the investigation of ancient ritual practices. PASTAtolls is a 4-yr Collaborative Research Project (PRC), with eight partners. For the first time, it brings together specialists in archaeology, anthropology, linguistics, palaeoecology and geomorphology with long experience on Polynesian atolls. Our multidisciplinary approach, structured in eight work-packages, will be deployed on five targeted atolls in three different archipelagos, characterized by various environmental conditions and cultural backgrounds (from west to east: Teti’aroa, Niau, Anaa, Takume and Temoe). Several field seasons will allow for data collection through archaeological excavations, palaeoecological studies, and ethnographic and linguistic works. While questions and issues tackled in this project are of primary concern to the Humanities, they also participate in the diachronic perspective on biodiversity, which biologists are lacking. They will further increase our knowledge about the resilience mechanisms of Pacific populations in the face of global challenges.