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University of Nebraska–Lincoln's S. Kathleen Lyons is providing a new framework—Earth system engineering—for examining how organisms, including humans, have fundamentally altered ecosystems on a global scale across hundreds, thousands or millions of years.

The is published in Trends in Ecology and Evolution and builds on ecosystem engineering, which describes how organisms change their physical environment to thrive. Earth system engineering is a novel approach that distinguishes between engineering behaviors that have transformed the planet and those that have only local effects.

"I think that this paper is going to revolutionize how ecologists think about ecosystem engineering and will spur research into how human Earth system engineering is similar or different from past events that transformed the planet," said Lyons, associate professor of biological sciences.

Whereas ecosystem engineering is thought of as more limited, and ecosystem engineers are often single species, Earth system engineering describes processes that alter the structure and function of the whole planet over longer periods of time.

"We propose the term 'Earth system engineering' to describe biological processes that change the functioning of Earth as a whole—chemically, physically, or in terms of climate," said Simon Darroch, scientist with the Senckenberg Museum of Natural History in Germany and second lead author on the paper.

The framework for Earth system engineering offers a foundation for answering new questions about how the planet changed over millions and billions of years to allow for life that exists today and possibly predict the consequences of climate changes and species extinctions.

"There are really important distinctions that this makes, particularly between Earth system engineers and ecosystem engineering, and it will have some effect on predictions people want to make about evolutionary patterns," said Peter Wagner, co-author and professor in Earth and atmospheric sciences and in biological sciences.

Using the fossil record, the authors of the framework look at previous Earth system engineering and its consequences, including the development of photosynthesis—creating more oxygen for animal life—or rooting systems in prairie plants, changing soil structures and nutrients. Examining past Earth system engineering events, it is noted that these events took numerous and varied types of species to achieve and posits the question of whether humans are a unique type of Earth system engineer because of their singular ability to change whole planetary ecosystems through multiple engineering behaviors including burning of fossil fuels, animal husbandry and urbanization.

"We've asked, essentially, the question—are humans unique in evolutionary history—or are we just the most recent in a long line of what this paper is calling Earth system engineers?" Lyons said. "We realized that one of the things that stymied our efforts to answer this question is not having a framework for studying ecosystem engineering in deep time versus studying ecosystem engineering in the present."

The framework was developed by a large working group of scientists. Lyons is the lead principal investigator, and she is joined by co-PIs Darroch; Peter Wagner, professor of Earth and atmospheric sciences at Nebraska; and Cindy Looy of the University of California–Berkeley.

"We started with a discussion about how ecosystem engineering processes that have local to regional scale effects are different from the kinds of planetary scale processes that we were interested in understanding with respect to humans," Lyons said. "The framework synthesizes information that people have been thinking about. Formalizing it and giving it a language is going to allow for an acceleration, I think, in people's understanding of how the Earth is bio-engineered."