"People have been really interested in nitrogen in current times because it's a major pollutant," said Kendra McLauchlan, assistant professor of geography and director of the university's Paleoenvironmental Laboratory. "Humans are producing a lot more nitrogen than in the past for use as crop fertilizer, and there is concern because excess levels can cause damage. The mystery, though, is whether the biosphere is able to soak up this extra nitrogen and what that means for the future."
"Based on what we learned from the past, if the response of plants to elevated carbon dioxide slows, nitrogen availability is likely to increase and ecosystems will begin to change profoundly," McLauchlan said. "Now more than ever, it's important to begin monitoring our grasslands and forests for early warning signs."