A group of 22 scientists sounded an alarming call to action last week.
Their paper in the June 7 issue of Nature, a highly regarded, peer-reviewed journal, carries the benign-sounding title, "Approaching a State Shift in Earth's Biosphere." But their conclusions are nothing short of a disaster warning.
This group of biologists, ecologists, geologists, paleontologists and complex-system theoreticians from the United States, Canada, South America, and Europe have spent a year and half reviewing evidence that Earth may be approaching a state shift, a "tipping point" at which the global ecosystem may shift abruptly and irreversibly from one state to another.
If this happens, the world as we know it may not be recoverable, and these scientists conclude that this outcome is looking more and more likely.
An article by Paul Basken in last week's Chronicle of Higher Education explains the scientists' findings in layman's terms. According to Basken, the report centers on a measure of how much of the Earth's surface has been altered by people, "from forests and prairies to uses such as cornfields and parking lots."
Human beings now number more than 7 billion, and we have transformed 43 percent of the land we live on from its natural state to something else. That figure is expected to top 50 percent by 2025, when the world's population reaches 8 billion. At that point, environmental damage such as species extinctions, climate change, and chemical contamination may have accumulated to such an extent as to be catastrophic.
The report's lead author, Anthony D. Barnosky of the University of California at Berkeley, told Basken that the scope of these problems demands a global response. And this is where scientists like Barnosky and his co-authors begin to get really worried. Up to now, the nations of the world have not shown themselves to be either willing or able to cooperate on the scale that scientists now believe is necessary to avert irreparable harm to the planet.
We will have another opportunity this month at the United Nations Conference on Sustainable Development in Rio de Janeiro, Brazil, June 20-22. Dubbed Rio+20 because it is taking place 20 years after the Earth Summit held in Rio in 1992, this conference may be one of our last, best chances to come together as a species and take concrete actions in time to avoid that environmental tipping point that Barnosky and his colleagues have warned us about.
At the Delaware Environmental Institute, the multidisciplinary research and education institute at the University of Delaware that I have the privilege of directing, we recognize the complexity of the environmental challenges we are facing. Responding to these challenges involves more than scientists providing data and politicians passing laws based on that data. Our global society encompasses a myriad of ideological, cultural, economic, and psychological factors that must be taken into account to structure workable solutions.
In order to navigate our way forward, we do need scientists to measure what is happening to the Earth and engineers to devise technological fixes. But we also need philosophers to examine the ethics of what we do in relation to our environment, and historians, writers, and artists to tell the story in a way we can hear and respond to. We need psychologists and sociologists to tell us why we are so resistant to change as individuals and communities and how we can overcome those barriers. And we need economists and policymakers to build in the proper incentives to our markets and our governance so that we adequately value and protect the natural systems on which our lives depend.
People from all walks of life and all schools of thought have one thing in common: we spend our lives on this planet being sustained by a natural system that provides us with air, soil, water and food -- and abundant wonder and beauty -- but which is showing increasing signs of strain. There can be little doubt that we are the primary source of that strain. Let's hope that we can find a way to ease the strain before we reach the breaking point.
Dr. Donald L. Sparks is the S. Hallock du Pont Chair in the Department of Plant and Soil Sciences and director of the Delaware Environmental Institute at the University of Delaware. He is an internationally recognized scientist in the field of environmental soil chemistry.