Publications by authors named "Ann E Holbourn"

In parallel with pronounced cooling in the oceans, vast areas of the continents experienced enhanced aridification and restructuring of vegetation and animal communities during the Late Miocene. Debate continues over whether CO-induced global cooling was the primary driver of this climate and ecosystem upheaval on land. Here we present an 8 to 5 Ma land surface temperatures (LST) record from East Asia derived from paleosol carbonate clumped isotopes and integrated with climate model simulations.

View Article and Find Full Text PDF
Article Synopsis
  • The transition from the late Miocene to early Pliocene was marked by significant climate changes, including increased CO levels, which can help understand current climate responses in Asia.
  • This CO-induced warming led to increased moisture transport in East Asia's summer monsoon, while also causing arid conditions in Central Asia due to higher evaporation rates.
  • The study supports the idea that wetter regions will become wetter and drier regions will become drier due to climate change, highlighting a complex response to solar insolation patterns over time.
View Article and Find Full Text PDF

Much of our understanding of Earth's past climate comes from the measurement of oxygen and carbon isotope variations in deep-sea benthic foraminifera. Yet, long intervals in existing records lack the temporal resolution and age control needed to thoroughly categorize climate states of the Cenozoic era and to study their dynamics. Here, we present a new, highly resolved, astronomically dated, continuous composite of benthic foraminifer isotope records developed in our laboratories.

View Article and Find Full Text PDF

The late Miocene offers the opportunity to assess the sensitivity of the Earth's climate to orbital forcing and to changing boundary conditions, such as ice volume and greenhouse gas concentrations, on a warmer-than-modern Earth. Here we investigate the relationships between low- and high-latitude climate variability in an extended succession from the subtropical northwestern Pacific Ocean. Our high-resolution benthic isotope record in combination with paired mixed layer isotope and Mg/Ca-derived temperature data reveal that a long-term cooling trend was synchronous with intensification of the Asian winter monsoon and strengthening of the biological pump from ~7 Ma until ~5.

View Article and Find Full Text PDF