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Although the Nile is one of the largest rivers in the world and played a central role in ancient Egyptian life, little is known about its response to climatic change during the Holocene. Here we present a framework for the evolution of the Egyptian Nile, demonstrating how climatic and environmental changes have shaped the landscape of the Egyptian Nile Valley over the past 11,500 years, including the civilization of ancient Egypt (~5,000 to 2,000 years ago). Using data from over 80 sediment cores drilled in a transect spanning the Nile Valley near Luxor, pinned in time by 48 optically stimulated luminescence ages, we reconstruct the dynamics of the Nile River during the Holocene in the vicinity of UNESCO World Heritage sites such as Karnak and Luxor temples. According to our reconstruction, valley incision occurred from the start of the record until approximately 4,000 years ago and then rapidly shifted to massive floodplain aggradation. We argue that this relatively abrupt change in the riverine landscape near Luxor from the Middle to Late Holocene was linked to a shift towards a drier regional hydroclimate around this time. Such a dramatic change in river sediment dynamics could have had local agro-economic consequences.

The timing and formation of Earth’s first continents during the Archean are subjects of significant debate. By examining titanium isotope variations in Archean Tonalite-Trondhjemite-Granodiorite (TTG) rocks and using advanced thermodynamic modelling, we can narrow down the processes involved and emphasise the role of mafic precursor compositions. In our study of Eoarchean Isua metabasalts and Itsaq tonalites in southern West Greenland, we observed a pattern of increasing Ti isotope enrichment with higher SiO2 content, resembling the compositions found in modern subduction zone rocks. Our modelling suggests that the Ti isotope variations in TTGs can be best explained by a combination of partial melting of low TiO2 metabasalts and subsequent crystallisation of tonalitic magmas, resulting in heavier Ti isotopes. This means that Ti isotopes help us distinguish the contributions of various mafic sources and fractional crystallisation during TTG formation. In the case of Itsaq tonalites and many other Eoarchean TTGs, low TiO2 tholeiitic metabasalts with arc-like characteristics likely represent the mafic source rocks, suggesting the formation of some of Earth’s earliest continental crust within a proto-subduction zone setting.

Existing frameworks offer a holistic way to evaluate a food system based on sustainability indicators but can fall short of offering clear direction. To analyze the sustainability of a geographical indication (GI) system, we adopt a product-centered approach that begins with understanding the product qualification along the value-chain. We use the case of the GI Corsican grapefruit focusing on understanding the quality criteria priorities from the orchard to the store. Our results show that certain compromises written into the Code of Practices threaten the system's sustainability. Today the GI allows the fruit to be harvested before achieving peak maturity and expectations on visual quality lead to high levels of food waste. Its primary function is to help penetrate mainstream export markets and to optimize labor and infrastructure. Analyzing the stakeholders' choices of qualification brings to light potential seeds for change in the short run such as later springtime harvests, diversification of the marketing channels, and more leniency on the fruit's aesthetics. These solutions lead us to reflect on long-term pathways to sustainable development such as reinforcing the fruit's typicality, reducing food waste, reorganizing human resources, and embedding the fruit into its territory and the local culture.