‘Earth System Engineering’ examines impact of life

An international team including a professor from the University of Tennessee, Knoxville, has developed a new approach for understanding how living organisms—including modern humans—fundamentally change Earth’s ecosystems.

The researchers propose the concept of “Earth system engineering” in a study published in the scientific journal Trends in Ecology & Evolution. It encompasses biological processes that have a lasting impact on central parts of the planet—such as the atmosphere, oceans, and soil—and leave their mark over millions of years. 

The framework combines observations from the present with evidence from the fossil record and will allow new analysis on the role of modern humans. 

“Many human interventions—from the use of fossil fuels to industrial agriculture and the introduction of invasive species—have global, long-term effects,” said Jones/Bibee Professor Alycia Stigall, head of UT’s Department of Earth, Environmental, and Planetary Science and a co-author on the study. “Global warming and the worldwide extinction of species are obvious and grave consequences of our ‘Earth system engineering.’” 

At the University of Tennessee, Stigall and her students focus on understanding how species invasions act as ecosystem and Earth system engineers. One of their projects studies bedrock in Tennessee to examine how a major biotic invasion into the Nashville and Cincinnati regions 450 million years ago promoted extinction and the reorganization of shallow marine ecosystems. 

“Studying the patterns of change preserved in the fossil record helps us provide constraints to better understand the long-term consequences of the modern human-caused movement of species into new ecosystems,” Stigall said.

Prehistoric to Present Day

Since the emergence of life around 3.5 billion years ago, a wide variety of living organisms have influenced the planet. The changes can be local and over a limited time, such as when a beaver builds a dam, but others may extend beyond the species’ habitat or lifespan. 

To systematically explore the interventions of modern humans, the team of more than 20 paleontologists, biologists, and anthropologists led by Professor S. Kathleen Lyons from School of Biological Sciences at the University of Nebraska—Lincoln developed a new approach to study different types of “bioengineering” throughout geological history. 

The newly published study distinguishes between classic “ecosystem engineering,” where individual species locally change the distribution of important resources, thereby creating new habitats, and the new concept of “Earth system engineering” (ESE), whose effects are global and long-lasting. For example, 2.4 billion years ago photosynthesis led to an increase in the oxygen content of the air, creating the conditions for complex life, and the expansion of dense forests permanently changed the planet’s climate by affecting the reflection of sunlight. 

 “We want to use the concept to clarify, among other questions, whether such drastic transformations occur in clusters and whether their consequences can be predicted,” Lyons said. 

“The central question is whether today’s human-induced effects are truly unique, or whether there are parallels in geological history, and what can we learn from them,” said another of the study’s co-authors, Professor Simon Darroch, from the Senckenberg Research Institute and Natural History Museum in Germany. “In the fossil record, for example, we find evidence of phases in which ESE processes were weakened or interrupted, for instance in the wake of mass extinctions. Answering these questions can help us to better understand the long-term consequences of our actions in the Anthropocene.”