My paleoclimate research focuses on two intervals of the geologic record:
- Last Glacial Maximum (LGM) through the Holocene
- the Plio-Pleistocene period
In both cases, I am interested in global processes. I address these questions through detailed reconstructions in specifically targeted regions. Over the span of my career, I have worked in most of the World Ocean’s major basins.
Background
Our planet’s most dramatic climate changes are the shifts from glacial to interglacial conditions. According to the Milankovitch-Croll hypothesis, a fundamental tenant of paleoclimate research, these shifts occur in response to cyclic changes in the Earth’s orbit. Changes in the eccentricity, axial tilt, and the precession of the seasons control the amount of solar energy received at various locations through time. This influences oceanic and atmospheric circulation and causes the ice ages and the relatively warm periods between them.
On longer timescales, with trends or cycles of millions to billions of years, large-scale changes in solar luminosity (total solar output), tectonic shifts (mountain building and erosion), and biogeochemical cycling control climate. In the geologic past, these changes arose in response to the evolution of the Sun, Earth, and the Earth’s biosphere. On shorter timescales (<20,000 years per cycle), the interplay of more subtle changes in solar output, volcanic forcing, internal oscillations of the climate system and anthropogenic forcing drive climate variability. The most important of these “short-term” changes has been anthropogenic-forcing of the climate system from the Industrial Revolution to present.
Read more about my Paleoclimate Research Methods