The questions driving research in Quaternary climate, the period of geological time that includes the recent ice ages and interglacial climatic periods, and environmental change are important not only for our understanding of how the Earth System has changed in the past, but also because this time period represents the closest analog for what we will be seeing in the near future. My research focuses in part on understanding climate and environmental change in low latitude systems, such as in East Africa. At low latitudes, temperature changes are measureable, e.g. on glacial/interglacial timescales, but they are quite muted compared to high latitudes. In contrast, significant variability in the hydrological cycle is observed, often resulting in major shifts of arid zones associated with global climate change. Such changes in temperature and hydrology can have a significant impact on both terrestrial and aquatic biota – including humans. In Africa, my group has identified numerous significant changes in temperature over the past ~million years, including a warming of 3.5ºC from the Last Glacial Maximum to present, but also major changes just during the last 10,000 years, including a temperature shift of 2-4ºC that occurred at the end of the African Humid Period ~5,000 years ago – a time when temperatures of Lake Turkana were in fact warmer than they are today. Furthermore, we have identified a substantial increase in the temperature of Lake Malawi surface waters of ~2ºC over the past 100 years, most likely attributable to anthropogenic influences. These changes in temperature are associated with major shifts in rainfall as well. Ongoing research is exploring these climate shifts on longer timescales throughout East Africa, in an attempt to provide an environmental context for hominin development.
Dr. Josef Werne, Associate Professor and Director of Graduate Studies, received his PhD in Geological Sciences at Northwestern University in 2000 with an emphasis in Biogeochemistry. He was a Postdoctoral Research Scientist at the Royal Netherlands Institute for Sea Research from 2000-2002 and on the faculty of the Large Lakes Observatory and Department of Chemistry & Biochemistry (Assistant/Associate Professor) at the University of Minnesota Duluth before joining the Department in 2012. Dr. Werne spent a year in Perth, Australia as a Gledden Visiting Senior Fellow at the Institute for Advanced Studies of the University of Western Australia, as well as a visiting scientist in the Western Australia Organic and Isotope Geochemistry Centre at Curtin University (2009-2010).