Several faculty at Illinois study global change. Geological records of changing climate and paleoenvironment provide important information about how the earth system works. Prof. Jessica Conroy and Prof. Feng Sheng Hu extract climate and ecological records from lake sediment cores. Conroy's current research focuses on tropical climate dynamics, whereas Hu's recent projects concentrate mainly on arctic ecosystem changes. Prof. Surangi Punyasena, a paleobotanist, studies plant fossils and their environmental records. Dr. Brandon Curry works on glacial deposits of Illinois and the midwest; these deposits record past glacial conditions. Prof. Alison Anders studies the relationship between climate and erosion. Prof. Wendy Yang studies nitrogen and carbon dynamics in soils, which have a major impact on climate and nutrient cycling.