Vegetation changes accelerated climate shifts during late Miocene

A new study has revealed that changes in plant life had played a crucial role in speeding up major climate shifts during the late Miocene, a period that lasted from 11.6 to 5.3 million years ago.

The study, recently published in the journal Science Advances, was led by researchers from the Institute of Atmospheric Physics (IAP) of the Chinese Academy of Sciences.

The late Miocene represents an important period in Earth's history, characterized by a shift from the sustained warmth of the middle Miocene to cooler conditions more similar to those we experience today. While previous studies pointed to declining CO2 levels and tectonic movements as the main drivers of these changes, these factors alone were insufficient to fully explain the global climate transition.

A new study highlights how vegetation feedbacks, referring to changes in plant cover that influence climate, intensified cooling in high northern latitudes and altered rainfall patterns in lower latitudes.

In high northern latitudes, vegetation was likely dominated by dense forests before cooling temperatures transformed these areas into grasslands during the late Miocene, a change that further accelerated global cooling.

These findings demonstrate that vegetation changes amplified cooling by altering surface reflectivity and influencing water vapor, clouds and sea ice. In some regions, such effects were even more significant than the cooling caused by a decline in CO2.

By combining geological data and climate models, the study clarified the distinct roles of CO2, tectonic changes and vegetation feedbacks in shaping the climate during the late Miocene.

"This study helps us better understand the mechanisms behind the late Miocene climate shift and emphasizes how vegetation feedbacks can influence the global climate – both in the past and in the future," said Zhang Ran, a professor at the IAP.

Unlike today's rapid, CO2-driven warming, the late Miocene was characterized by cooling and declining CO2 levels. This study underscores the often-overlooked impact of plant life on climate systems, providing valuable insights for historical and future climate change research, Zhang added.

(Cover: An illustration of wildlife in the Miocene period. /VCG)