Questions: 1. What relationships exist between rapid climate, hydrologic, and ecosystem changes? Multi-century patterns of climate change and their effects on resources such as water present a key area of uncertainty in paleoclimatology. For this reason, I have used ground-penetrating radar (GPR) analyses and sediment cores from small lakes to evaluate rapid, century-scale hydrologic fluctuations. Thus far, my work supports the expectation that ecosystems may be highly sensitive even to modest climate changes.
2. At what scale could even modest climatic forcing, such as those during the Holocene, produce abrupt climate changes? A central goal of my dissertation (and now my postdoctoral research) is to understand how changes, such as those discussed above, fit into hemispheric patterns of climate change. Abrupt climate changes range from local shifts (e.g., only focused near shifts in ocean and atmospheric fronts) to global transformations. To evaluate the mosaic of such changes that may have developed across the Northern Hemisphere throughout the Holocene, my funding from NASA and a nationally competitive EPA STAR fellowship have allowed me to develop statistically-robust paleoclimate reconstructions based on >1600 fossil pollen datasets from Europe and North America. I am using the reconstructions to produce novel maps of the magnitudes and rates of Holocene temperature changes.
Given that the Holocene represents the baseline from which our current climate state is developing, and contains a wealth of paleoclimate data, organized study of the Earth System over this time period will provide useful empirical examples of changes that may be possible in a warm world.