06 July 2015
Dahr Jamail By Dahr Jamail, Truthout | Interview
Guy McPherson is a professor emeritus of evolutionary biology, natural resources and ecology at the University of Arizona, and has been a climate change expert for 30 years. He has also become a controversial figure, due to the fact that he does not shy away from talking about the possibility of near-term human extinction.
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While McPherson’s perspective might sound like the stuff of science fiction, there is historical precedent for his predictions. Fifty-five million years ago, a 5-degree Celsius rise in average global temperatures seems to have occurred in just 13 years, according to a study published in the October 2013 issue of the Proceedings of the National Academy of Sciences. A report in the August 2013 issue of Science revealed that in the near term, earth’s climate will change 10 times faster than during any other moment in the last 65 million years.
McPherson fears that we are well along in the process of causing our own extinction.
Prior to that, the Permian mass extinction that occurred 250 million years ago, also known as the “Great Dying,” was triggered by a massive lava flow in an area of Siberia that led to an increase in global temperatures of 6 degrees Celsius. That, in turn, caused the melting of frozen methane deposits under the seas. Released into the atmosphere, those gases caused temperatures to skyrocket further. All of this occurred over a period of approximately 80,000 years. The change in climate is thought to be the key to what caused the extinction of most species on the planet. In that extinction episode, it is estimated that 95 percent of all species were wiped out.
Today’s current scientific and observable evidence strongly suggests we are in the midst of the same process – only this time it is anthropogenic, and happening exponentially faster than even the Permian mass extinction did.
In fact, a recently published study in Science Advances states, unequivocally, that the planet has officially entered its sixth mass extinction event. The study shows that species are already being killed off at rates much faster than they were during the other five extinction events, and warns ominously that humans could very likely be among the first wave of species to go extinct.
So if some feel that McPherson’s thinking is extreme, when the myriad scientific reports he cites to back his claims are looked at squarely and the dots are connected, the perceived extremism begins to dissolve into a possible, or even likely, reality.
The idea of possible human extinction, coming not just from McPherson but a growing number of scientists (as well as the aforementioned recently published report in Science), is now beginning to occasionally find its way into mainstream consciousness.
“A Child Born Today May Live to See Humanity’s End, Unless …” reads a recent blog post title from Reuters. It reads:
Humans will be extinct in 100 years because the planet will be uninhabitable, according to Australian microbiologist Frank Fenner, one of the leaders of the effort to eradicate smallpox in the 1970s. He blames overcrowding, denuded resources and climate change. Fenner’s prediction is not a sure bet, but he is correct that there is no way emissions reductions will be enough to save us from our trend toward doom. And there doesn’t seem to be any big global rush to reduce emissions, anyway.
McPherson, who maintains the blog “Nature Bats Last,” told Truthout, “We’ve never been here as a species and the implications are truly dire and profound for our species and the rest of the living planet.”
Truthout first interviewed McPherson in early 2014, at which time he had identified 24 self-reinforcing positive feedback loops triggered by human-caused climate disruption. Today that number has grown to more than 50, and continues to increase.
A self-reinforcing positive feedback loop is akin to a “vicious circle”: It accelerates the impacts of anthropogenic climate disruption (ACD). An example would be methane releases in the Arctic. Massive amounts of methane are currently locked in the permafrost, which is now melting rapidly. As the permafrost melts, methane – a greenhouse gas 100 times more potent than carbon dioxide on a short timescale – is released into the atmosphere, warming it further, which in turn causes more permafrost to melt, and so on.
As soon as this summer, we are likely to begin seeing periods of an ice-free Arctic. (Those periods will arrive by the summer of 2016 at the latest, according to a Naval Postgraduate School report.)
Once the summer ice begins melting away completely, even for short periods, methane releases will worsen dramatically.
Is it possible that, on top of the vast quantities of carbon dioxide from fossil fuels that continue to enter the atmosphere in record amounts yearly, an increased release of methane could signal the beginning of the sort of process that led to the Great Dying?
McPherson, like the scientists involved in the recent study that confirms the arrival of the sixth great extinction, fears that the situation is already so serious and so many self-reinforcing feedback loops are already in play that we are well along in the process of causing our own extinction.
Furthermore, McPherson remains convinced that it could happen far more quickly than generally believed possible – in the course of just the next few decades, or even sooner.
Truthout caught up with McPherson in Washington State, where he was recently on a lecture tour, sharing his dire analysis of how far along we already are regarding ACD.
Dahr Jamail: How many positive feedback loops have you identified up until now, and what does this ever-increasing number of them indicate?
Guy McPherson: I can’t quite wrap my mind around the ever-increasing number of self-reinforcing feedback loops. A long time ago, when there were about 20 of them, I believed evidence would accumulate in support of existing loops, but we couldn’t possibly identify any more. Ditto for when we hit 30. And 40. There are more than 50 now, and the hits keep coming. And the evidence for existing feedback loops continues to grow.
In addition to these positive feedback loops “feeding” within themselves, they also interact among each other. Methane released from the Arctic Ocean is exacerbated and contributes to reduced albedo [reflectivity of solar radiation by the ice] as the Arctic ice declines. Tack on the methane released from permafrost and it’s obvious we’re facing a shaky future for humanity.