Aaron Diefendorf
University of Cincinnati, OH·Earth & Environmental Science
Some of Earth's largest environmental shifts, including the end of the last ice age, happened so quickly that no single trigger seems big enough to explain them. An alternative idea is that the climate system can sit near a tipping point and flip between two or more semi-stable states with little specific prompting.
- Fields
Earth & Environmental Science
Ecology & Evolution
- Topics
paleoclimate
last glacial maximum
abrupt climate change
- Grants
- 1 known grant, through Aug 2029
What they work on
- Synthesize existing Southern Hemisphere records of environmental change covering the descent into and abrupt exit from the last ice age, so patterns and rates can be compared on a common footing.
- Develop new records of past environmental conditions from the Falkland Islands using glacial, geochemical and sedimentological proxies in lake sediments and periglacial deposits laid down near former ice margins.
- Model the drivers of Earth system change across the glacial interval with an Earth System model, using the data synthesis and new Falkland Islands records as the metrics the model must reproduce.
- Test whether the observed patterns and rates of change match a nearly intransitive system that jumps between two or more semi-stable states, rather than a deterministic response to one specific trigger.
More about the research
If the ocean-atmosphere system really behaves this way, the models society uses to project long-term environmental change would need substantial revision.
Why it matters
Projections of future environmental change rest on the assumption that the climate system responds predictably to specific causes. If the last ice age instead shows abrupt jumps between semi-stable states, those projections, which inform agriculture, public health, national security and coastal planning, may need revision. New Southern Hemisphere records and model tests could tell us how fast such shifts can occur and what, if anything, sets them off.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
Brenda Hall
University of Maine, ME·Earth & Environmental Science
Synthesize existing Southern Hemisphere records of environmental change covering the descent into and abrupt exit from the last ice age.
Jessica Conroy
University of Illinois Urbana-Champaign, IL·Earth & Environmental Science
Map an oxygen isotope "isoscape" of the modern tropical Pacific from long-running seawater and precipitation collection sites, showing how seawater and rainfall isotope values shift between El Niño and La Niña phases.
Alia Lesnek
CUNY Queens College, NY·Earth & Environmental Science·Early-career
Reconstruct when the Cordilleran Ice Sheet retreated across Southwest Alaska, using geologic mapping and cosmogenic nuclide surface exposure dating, which measures atoms that build up in rock once it is exposed.
The school
University of Cincinnati: 18 labs on PI Pages, $740M a year on research, 275 research doctorates a year.
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