Lakes and wetlands are major sinks for carbon and are dynamic systems that integrate the environment, climate, and tectonic forcing into a continuous, high-resolution archive, which can then be used to understand present and past climate changes. Lacustrine sediments have long served as an archive of terrestrial environmental changes because they contain a myriad of isotopic, chemical, and biological proxies that characterize changes in their past climate and environment. Furthermore, geochemical and sedimentological analyses of these sediments can help to determine the past environment in which the sediments were deposited.

Lake deposits are particularly well horizontally bedded or laminated, and in addition show frequent vertical changes in lithology. The principal reasons for these phenomena are that lakes and their sediments are not significantly affected by waves and currents and are very sensitive to small changes in climate, catchment area, and other environmental factors. This sensitivity results in a relatively quick responsiveness to external forcing variability, thereby integrating information about changes in the catchment area. Changes in air temperature or regional land use can be reflected within months to decades in the inputs to the lake’s sedimentary record. The rapidity of this response varies both within a lake, for examples from near shore to offshore environments, and between lakes. However, typically, small lakes respond more quickly and more definitively to a perturbation than larger lakes. Geothermal system is a clean source of renewable energy, geothermal power plants only emitting steam. Nonetheless, geothermal technologies are now being used to analyze the possible environmental impacts of geothermal energy associated with power plant life cycles, water use, and seismicity related to enhanced geothermal systems. These geothermal technologies work to address the environmental impacts of geothermal technologies through research and analysis of geothermal project life cycles, water use, and seismicity issues.

The aim of this Special Issue is to gather the latest research into the use of geochemical and geothermal systems to evaluate environmental changes and impacts. We welcome both original research and review articles.

Potential topics include but are not limited to the following:

• Chemical and physical assessment of surface water quality in seasonal variation
• Geothermal resources in environmental exploitation and utilization
• Geochemistry and mineralogy of solid waste materials
• Bio- and geochemical parameters of the environmental risk of mobilized mercury from disposal sites
• Geotechnical and geo-environmental engineering for biodegradable geosynthetics
• Geochemical issues in wetland resource utilization and research
• Assessment of heavy metal contamination of sediments in rivers
• Environmental assessment and risks of underground geoenergy resource exploitation
• Geothermal resources for local sustainable development