Title: “Carbon consequences of a warming Arctic”

Abstract: : Carbon has been accumulating in northern high latitude ecosystems for thousands of years, but as the climate warms, the large pool of carbon is at risk of being thawed, decomposed, and transferred to the atmosphere. Despite the potential importance of changes in northern carbon cycling for global climate, both the sign and magnitude of the current and future carbon balance of the Arctic remain highly uncertain. To address this uncertainty, I will present ecosystem carbon cycling results from a warming and drying experiment in a sub-arctic tundra landscape, and then I will focus on carbon cycling in the Arctic during the period of greatest uncertainty, the winter. Using a new synthesis of winter CO2 fluxes that span northern high latitude terrestrial ecosystems, I examine the drivers of winter respiration, estimate current winter CO2 emissions for the northern permafrost region, and project winter CO2 emissions under two future climate scenarios--Representative Concentration Pathways (RCP) 4.5 and 8.5. While climate change may shift the Arctic from a carbon sink to a source, the magnitude of this response will be highly dependent on future climate change mitigation efforts.

Short Bio: Dr. Natali’s research examines the response of terrestrial ecosystems to a changing environment, with an emphasis on feedbacks to carbon cycling from northern high latitude systems. While a postdoctoral fellow at the University of Florida, she worked on permafrost ecosystems, establishing a large-scale warming experiment in interior Alaska. That project tests hypotheses about feedbacks to the global carbon cycle as a result of warming air and soil temperatures and thawing permafrost. More recently, she established a tundra drying experiment to examine interactive effects of permafrost thaw and changes in soil moisture on ecosystem carbon exchange. Dr. Natali was a National Science Foundation Polar Programs Postdoctoral Research Fellow. She holds a B.S. from Villanova University and a Ph.D. from Stony Brook University.