The scientific approach focuses on the holistic use of biogeochemical tracers, such as elemental concentrations (Cd, Pb, PGE etc.) and isotopic ratios (D/H, 18O/16O, 87Sr/88Sr...), - in some cases referred to as "proxies" - that are measured on a substrate (e.g. mineral phase, fossil, mussel-shell, teeth, seawater, ice cores etc.) to infer specific environmental parameters (such as condition of formation, temperature, acidity, salinity, CO2 level, composition, bio-productivity etc.). Variations in these "proxies" characterize the factors triggering or resulting from (paleo)environmental changes and document at different scales, the short and/or long-term effects of these modifications on the Global Earth System. Although not commonly carried out, the analyses in close conjunction of modern and ancient global changes, including pollution are highly complementary and mutually beneficial. Ongoing changes are monitored and documented at very high resolution, while the geological record traces the evolution of these changes through time, providing an extra dimension, missing from the modern data. The themes briefly presented below constitute cutting-edge international research challenges. To address them, innovative analytical procedures are continuously being developed using the facilities available at the VUB and its partner universities. This analytical toolbox is then applied to various Earth and Environmental Science problems, often coupled with modeling.