If you’re the sort of person who woke up Friday morning worrying not just about the potential for sudden economic chaos following the sequester, but also the potential for human population growth and industrial activity to spur sudden ecosystem collapse on a planetary scale, take heart (and perhaps a Xanax). Some reassuring words are percolating on both fronts — though as it concerns the planet’s health in particular, the accuracy of those reassurances is in question.
On the first point: the sequester’s impacts on the wider economy, while almost certainly painful in the long-run, will likely be uneven and gradual. This being an environmental column, I’ll leave a fuller dispensation of these ideas to my far more qualified colleagues in the Business section, and you’ll also find meditations on the topic here, and here and here.
As for Planet Earth, a paper published Thursday in the journal Trends in Ecology and Evolution suggests that while human society does a very thorough job of modifying and, often enough, permanently and abruptly changing the dynamics of local and regional ecosystems, the collective impact of all this on a planetary scale is too often overstated.
Dire warnings that our localized impacts could trigger global-scale “tipping points,” after which the spinning cogs and gears that underpin our entire terrestrial biosphere are thrown abruptly and permanently out of whack, have no scientific basis, the authors argue. Global-scale changes, such that they are, come about smoothly and slowly, they say.
“This is good news because it says that we might avoid the doom-and-gloom scenario of abrupt, irreversible change,” Professor Barry Brook, lead author of the paper and director of Climate Science at the University of Adelaide in Australia, said in a statement accompanying the study’s release. “A focus on planetary tipping points may both distract from the vast ecological transformations that have already occurred, and lead to unjustified fatalism about the catastrophic effects of tipping points.”
“An emphasis on a point of no return is not particularly helpful for bringing about the conservation action we need,” Brook added. “We must continue to seek to reduce our impacts on the global ecology without undue attention on trying to avoid arbitrary thresholds.”
This, of course, flies directly in the face of a growing body of research over the last several years — much of it suggesting that there are very real planetary boundaries beyond which the entire terra machina starts to break down. This was the core of an extensive exploration published in the journal Nature in 2009.
In an email message, James E. Hansen, who heads the NASA Goddard Institute for Space Studies and is an adjunct professor at Columbia University’s Earth Institute, said that tipping points may unfold more smoothly than people generally understand, but that they represent points of no return nonetheless. He also suggested that dismissing the notion of global tipping points out of hand was a mistake. “Tipping points are real, albeit misunderstood by some people,” he said.
To read the full article, please click here: http://www.huffingtonpost.com/tom-zeller-jr/global-tipping-points_b_2793154.html
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