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Mid-Coast Audubon Talk with Geology Professor Beth Koffman

Thursday, February 20 @ 6:30 pm - 8:00 pm

Bess G. Koffman, Assistant Professor of Geology at Colby College will present — Climate Change: How Do We Know?

How do we know that Earth’s climate is changing? How do current trends fit into longer-term, natural cycles of climate change? How will changes in global climate impact us here in Maine?

This talk will focus on establishing the evidence for present-day climate change, and placing it in the context of past climate changes. We will use data from a range of natural climate archives, such as lake sediment cores, ice cores, and tree rings, to learn how climate has changed through time, both globally and here in Maine.  Dr. Bess Koffman, a geology professor at Colby College, is a paleoclimate scientist with twelve years’ experience working in the field of ice core paleoclimatology. She will speak about her research using ice cores from Antarctica and Alaska to study Earth’s climate. Dr. Koffman’s research is focused on learning about past changes in Earth’s atmospheric circulation, or winds. She uses mineral dust as a tracer of past wind patterns by measuring the dust particle size distribution (a proxy for distance to source and wind strength) and its geochemical composition (to determine provenance and transport pathway). She also studies the impacts of dust and volcanic deposition on marine ecosystems, where these particles can serve as an important fertilizer. She teaches the following courses at Colby: Earth Systems Chemistry; Earth’s Climate: Past, Present, and Future; Topics in Geochemistry; and Paleoceanography.


B.A. Geology, Carleton College
Ph.D. Earth and Climate Sciences, University of Maine
NSF Postdoctoral Fellowship, Lamont-Doherty Earth Observatory of Columbia University
Society of Fellows Postdoctoral Fellowship, Dartmouth College

Areas of Expertise

  • Paleoclimate
  • Sediment geochemistry
  • Ice cores
  • Climate change
  • Radiogenic isotopes
  • Atmospheric dust

Current Research

“I study past changes in Earth’s climate system using a combination of field and laboratory approaches. I am interested primarily in understanding how and why the atmospheric circulation has changed through time and the impacts these changes have had on terrestrial and marine environments. Earth’s atmospheric circulation influences large-scale climate variability in several important ways: it affects the transport and delivery of oceanic heat; it exerts a strong influence on the exchange of carbon dioxide (CO2) between the ocean and atmosphere; and it plays a large role in determining global rainfall distribution. Further, because the atmosphere can respond rapidly to climate perturbations, it is central to understanding the mechanisms driving changes in Earth’s climate on a range of timescales. I use mineral dust as a tracer of past wind patterns by measuring the dust particle size distribution (a proxy for distance to source and wind strength) and its geochemical and isotopic composition (to determine provenance and transport pathway). My approach couples high-resolution archives of past environmental change, such as ice core records, with state-of-the-art analyses of dust particle size and composition. My research to date has focused on three major themes: 1) the impact of dust on marine ecosystems, 2) reconstructing past changes in mid-latitude wind belts, and 3) the transport of aerosols from explosive volcanic eruptions.


Thursday, February 20
6:30 pm - 8:00 pm
Event Category:


Camden Public Library
55 Main Street
Camden, ME 04843 United States