Riverine Geochemical Response to Global Climate Change

Rivers play central role in material exchange between terrestrial and lacustrine and marine aquatic environments through weathering, erosion, carbon and nutrient cycling, and contaminant transport as well as being important in global biogeochemical cycles and the provision of ecosystem services. Global climate change affecting both temperature and precipitation have a host of interrelated consequences that affect the diverse processes that determine river geochemistry. These include shifts in water temperature, changes in flow volumes, the thawing of permafrost and melting of glaciers, and modification of vegetative land cover/land use and wildfire patterns and intensity that consequently alter geochemical reactions that govern stream chemistry to accelerate rock weathering, modify water quality and stream sediment dynamics, alter riverine biodiversity, and shift carbon and nutrient cycles on local, regional, and global scales. As such, global climate change may drive riverine aquatic systems critical for ecosystem function to change, inducing both positive and negative feedback that influence the chemical composition of river waters in both natural as well as agricultural, suburban, and urban environments. As river flow volumes a diminish in a warmer climate, higher solute concentrations will deteriorate dissolved oxygen levels and water quality even without human perturbation. However, the direction and magnitude of these responses vary considerable amongst terrains and catchments because of differences in lithology, soil development, ecosystem structure, hydrology, and human disturbance. Uncertainties remain concerning the relative contributions of climate-forcing and non-climatic pressures, the effects of extreme events, the persistence of geochemical responses, and the implications for downstream and coastal environments. The connection between short-term observations and long-term trends is not well understood and requires integration of chemical, isotopic, and modelling approaches across spatial scales.We invite of papers to this special issue of Frontiers in Geochemistry that will help deepen our understanding of river geochemistry in the face of changing global climate. Contributors to the special issue will be expected to review papers of other contributors. This research topic aims to present current cross-disciplinary knowledge and in so doing advance understanding of how global climate change influences the production, mobilization, transformation, and export of geochemical constituents to and from river systems. Submissions may address observations, experiments, modelling, palaeoenvironmental reconstructions, or integrated approaches that distinguish climate-related effects from those associated with land use, pollution, dams, and other anthropogenic pressures. It will examine the mechanisms controlling riverine compositional responses, identify the factors that regulate spatial and temporal variability, and assess consequences for watershed functioning, carbon and nutrient budgets, water quality, and downstream ecosystem services. To gather further insights into climate-sensitive geochemical processes in rivers and their connected watersheds, the scope includes studies of surface-water from headwaters to river deltas, while also recognising the importance of groundwater, soils, floodplains, lakes, and coastal receiving environments. Thus, we welcome articles addressing, but not limited to, the following themes:- Climate-driven changes in chemical weathering and erosion- Long-term records of riverine geochemical change- Transport and transformation of dissolved organic matter- Nutrient mobilization, retention, and export- Trace metals, metalloids, and emerging contaminants- Isotopic and elemental tracers of sources and processes- Riverine carbon cycling, carbon dioxide emissions, and carbon export- Geochemical responses to floods, droughts, wildfires, and heatwaves- Glacier retreat, permafrost thaw, and high-latitude river geochemistry- Hydrological change, residence times, groundwater-surface water interactions, and watershed connectivity- Sediment-associated geochemistry and floodplain processes- Interactions among climate change, land use, and pollution- Remote sensing, reactive-transport modelling, and data-driven approaches- Implications for water quality on human and ecosystem health, and downstream environments- Catchment management, adaptation, restoration, and nature-based solutions- Long term impact of either urbanization or agricultural activities on river geochemistry Topic editors: Russell Harmon, William Berry Lyons Source: https://www.frontiersin.org/research-topics/84979/riverine-geochemical-response-to-global-climate-change