Change in North Dakota Since the Last Glaciation
The terms global change and global warming have entered our everyday language. We are forced to concede that our activities have already contributed to the degradation of landscapes and the loss of biodiversity, and are probably contributing to climate change. With the record setting floods in the Red River and Missouri River valleys in 1997, Devils Lake at its highest level in historical time, and farmland being lost to coalescing lakes in the southeastern counties, North Dakotans know only too well the effects of climate change. From 1988 to 1992 the State experienced drought conditions but since then North Dakota has been in a wet cycle. North Dakotans are stoical when it comes to weather but even so there is a concern about what the future will bring. Most of our knowledge of climate change comes from an instrumental record that is only 100 years in length. This record has been extended by dendroclimatology and by high resolution paleontological and geochemical studies of lake sediments. What these studies are showing is that 100 years is far too short a time to show the variability in the climate record.
In recent years, our knowledge about climate change in North Dakota, especially since the last glaciation, has grown considerably. In winter, the frozen surfaces of North Dakota's lakes provide a perfect platform for coring lake sediments. The use of casing and the application of stronger and lighter alloys in coring rods now make it possible to obtain longer and more complete cores than ever before. Accelerator Mass Spectroscopy (AMS) has revolutionized radiocarbon dating so that now only small amounts of carbon are needed for high quality dates. This makes it possible to calculate rates of processes with greater accuracy than previously.
The following report borrows heavily from the research of Eric Grimm (Illinois State Natural History Museum), Shari Fritz (University of Nebraska), Kate Laird (Queens University, Ontario, Canada), Emi Ito (University of Minnesota), Walter Dean, and J. Platt Bradbury (United States Geological Survey).
Dr. Allan Ashworth, Chairman
130 Stevens Hall
North Dakota State University
Fargo, ND 58105