Civilization has crossed four of nine so-called planetary boundaries as the result of human activities, suggests a recent study.
Researchers at the University of Wisconsin said that the climate change, the loss of biosphere integrity, land-system change and altered biogeochemical cycles like phosphorus and nitrogen runoff have all passed beyond levels that put humanity in a "safe operating space."
Researcher Steve Carpenter said that it should be a wake-up call to policymakers that people are running up to and beyond the biophysical boundaries that enable human civilization to exist.
For the last 11,700 years until roughly 100 years ago, Earth had been in a "remarkably stable state," says Carpenter. During this time, known as the Holocene epoch, "everything important to civilization" has occurred, like from the development of agriculture, to the rise and fall of the Roman Empire, to the Industrial Revolution.
While the study focuses on several of these, including climate change and a troubling loss of biodiversity, Carpenter led the examination of biogeochemical cycle changes and looked at two elements essential to life as people know it, phosphorus and nitrogen.
Carpenter added that human have changed nitrogen and phosphorus cycles vastly more than any other element and the increase is on the order of 200 to 300 percent. In contrast, carbon has only been increased 10 to 20 percent and looks at all the uproar that has caused in the climate.
Carpenter noted that Wisconsin and the entire Great Lakes region are some of the places overloaded with nutrient pollution, but there are other places where billions of people live that are undersupplied with nitrogen and phosphorus.
Carpenter concluded that it might be possible for human civilization to live outside Holocene conditions, but it's never been tried before, since civilization can make it in Holocene conditions, so it seems wise to try to maintain them.
The study is published in Science.