Once a tipping point is passed, a major change occurs, one that may be difficult or impossible to reverse. If a business crosses the tipping point threshold, the worst that can happen is that it goes bankrupt. But what if Earth passes that point with respect to its environment?
The April, 2010, issue of Scientific American (SA) is devoted to the topic of “Managing the Earth’s Future.” One featured article, “Boundaries for a Healthy Planet,” concerns “thresholds for key environmental processes that, if crossed, could threaten Earth’s habitability.” Nine processes are discussed — biodiversity loss, land use, freshwater use, nitrogen and phosphorus cycles, stratospheric ozone, ocean acidification, climate change, chemical pollution, and aerosol loading in the atmosphere. The bottom line, as summarized by the SA website, is that “a team of 30 scientists across the globe have determined that the nine environmental processes named above must remain within specific limits, otherwise the ‘safe operating space’ within which humankind can exist on Earth will be threatened. Amid some controversy, the group has set numeric limits for seven of the nine so far (chemical pollution and aerosol loading are still being pinned down). And the researchers have determined that the world has already crossed the boundary in three cases: biodiversity loss, the nitrogen cycle and climate change.”
The University of Minnesota’s Institute on the Environment, whose director, Jonathan Foley, is the author of the above article, has produced a three minute video about Earth’s tipping points that is worth a look. Just click on the screen below to view it.
Foley and the other researchers who contributed to the article are not the only ones in the scientific community who are concerned about Earth passing environmental tipping points. James Lovelock, perhaps best known for his Gaia Theory of Earth as a living system, in his books, lectures, and interviews, says that Earth’s climate is past the point of no return and destined for runaway “global heating,” as he prefers to call it. (“Warming is cozy and comfortable . . . . Heating is something you want to get away from.”) But at age 89, he does not expect to be around to experience the worst of it himself. In his book, The Revenge of Gaia: Earth’s Climate Crisis and the Fate of Humanity, he warns, “Civilization is in grave danger. . . . Earth is now returning to the hot state it was in before, millions of years ago, and as it warms, most living things will die. Once started, the move to a hot state is irreversible . . . . Before this century is over billions of us will die and the few breeding pairs of people that survive will be in the arctic where the climate remains tolerable.” His worst case scenario forsees civilization reduced to “broken rabble led by brutal war lords.” In an ideal world, or rather an ideal civilization, mankind would “overcome the self-generated threat of deadly climate change, caused by our massive destruction of ecosystems and global pollution,” and would “ensure that our numbers are always commensurate with our and Gaia’s capacity to nourish them . . . . a stabilized population of about half to one billion.” This we have failed to do, so “in the end, as always, Gaia will do the culling and eliminate those that break her rules.”
In Peak Everything: Waking Up to the Century of Declines, Richard Heinberg addresses the “frightening array of peaks” we face in the new century: oil, natural gas, coal, population, grain, uranium, climate stability, fresh water, arable land, wild fish harvests, and yearly extraction of some metals and minerals (including copper, platinum, silver, gold, and zinc). Heinberg notes the “societal pattern of denial” about this, and warns that talking about it “is not likely to win votes, lead to a better job, or even make for pleasant dinner banter.” And yet, to ignore these crises is to ensure that they will unfold in the worst possible way. “It is hard to escape the conclusion that, while the 20th century saw the greatest and most rapid expansion of the scale, scope, and complexity of human societies in history, the 21st will see contraction and simplification. The only real question then is whether societies will contract and simplify intelligently or in an uncontrolled, chaotic fashion.” The introduction to Heinberg’s book is on the Global Public Media website.
Here are some links to other websites with information about Earth at the threshold of, or having already passed, crucial environmental tipping points:
http://www.nasa.gov/topics/earth/tipping_points.html
http://www.cnsnews.com/news/print/58316
http://www.celsias.com/article/ocean-acidification-part-ii-tipping-planet-already/
http://dotearth.blogs.nytimes.com/2009/03/28/tipping-points-and-the-climate-challenge/
http://www.globalstewards.org/issues.htm
http://www.pbs.org/journeytoplanetearth/stateoftheplanet/index_freshwater.html
http://www.theoildrum.com/files/Tipping%20Point.pdf
http://www.treehugger.com/files/2010/02/amazon-rainforest-near-tipping-point.php
http://rawstory.com/rs/2010/0510/fears-irreversible-damage-natural-environment/
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