For tonight's Conversations with Great Minds I´m joined by Guy McPherson, a Professor Emeritus of Natural Resources, Ecology and Evolutionary Biology at the University of Arizona. Guy is one of America's most influential experts on global warming, and writes about a variety of climate change related issues for the Arctic news blog and his own website Nature Bats Last. In the field of the climate science, Guy is best known for his assertion that runaway global warming is already on a path to cause the extinction of the human race, an idea he has written about in his book Going Dark. Guy McPherson joins us now, from our New York City studio. Guy, welcome to the program. Thank you, Tom. I appreciate the oportunity of being with you today. Thanks for being with us. First of all, just, very briefly, if you could give us a little background on who is Guy McPherson and why should we listen to you, your background credentials and what brought you to this to this place. Sorry, the sound is cutting out pretty badly here.
I think you asked me to give a background on the situation with respect to climate change. -Yes. -Ok. Well, I think I have a slide that I sent you that you can pick up now that shows carbon dioxide levels and how high they are relative to historical records. Carbon dioxide levels today are probably higher than they have been last 20 million years. We've had human beings on the planet for about 2 million years. So, carbon dioxide levels in the atmosphere alone represent a major threat to the persistence of humans. In fact, looking only at carbon dioxide, John Davies, writing for the Arctic Methane Emergency Group last September, claimed that we are already at a point that we could end… most habitat for humans on Earth by 2040. He's taking into account only carbon dioxide in the atmosphere one of a handful greenhouse gases we continue to emit.
Tim Garrett had an excellent paper in climatic change published in November 2009, but actually submitted in 2007, so we've known since 2007, that only collapse of Industrial Civilization prevents runaway climate change. That goes back a long time now, that's 7 years, since we've had that information, and, obviously, we haven't experienced collapse. By collapse, what Tim Garret is talking about, what I'm talking about, is no fuel at the filling station, no food at the grocery store, no water coming out of municipal taps. If we don't cease industrial activity, in other words, all industrial activity, we will trigger runaway greenhouse effect. Only collapse prevents runaway greenhouse. And that's just looking at carbon dioxide in the atmosphere.
If we go to another slide… I sent you a slide that shows that the Earth is within 1 percent of being uninhabitable, about 1.5 kilometers closer to the Sun, according to a paper published last year in the Astrophysical Journal. And Earth goes out at the habitable zone because we… we get too close to the Sun. – The Earth is that little dot up in the corner. Again, that assumes only one of the the many greenhouse gases that we're emitting, so we're so close to the Sun, so close to the inner edge of the habitable zone for life on Earth that even a minor change in atmospheric composition could pushes out at the habitable zone. Well, we haven't made minor changes in the atmospheric chemistry of the Earth. We've made major changes in the atmospheric chemistry of the Earth. We´re aproximately at 400 parts-per-million carbon dioxide in the atmosphere compared to the 280 parts-per-million when industrial activity began in the 1700.
We' re at nearly 2000, maybe 1800 or so parts-per-billion of methane in the atmosphere. relative to about 700 parts-per-billion, at the beginning of the Industrial Revolution. So, just considering those two, of a handful of greenhouse gases, we've made major changes in atmospheric composition within a relatively short period of time. And so, it appears that we could push Earth out at the habitable zone by making profound changes in atmospheric chemistry. You've probably heard about the contrarian myth that the Earth´s temperature has plateaued, global average temperature has plateaued, within the last 15, now 16 years, since March of 1998. Well, we now know that that heat, and I sent you a slide that shows where that heat is going. If you take a look at that slide, that shows that there's been an acceleration of the heat content in the oceans, since 1998. So, based on land surface temperature records it appears that global average temperatures have plateaued, but, in fact, 13 of the 14th warmest years on record have been since the year 2000.
And most of that heat is being dumped into the ocean, absorbed by the oceans, instead of on land. Well, as we know ocean is 2/3 or so of the total cover of the Earth, and so that's a lot of potential heat going into the oceans. it could be that, when we have an El Niño event, as appears relatively likely, later this year, it could be that a bunch of that heat is released from the oceans. Looking at 1 of the 30 irreversible feedback loops we´ve triggered, self-reinforcing feedback loops, that of methane in the atmosphere… if you take a look at that slide of the globe, that shows the methane concentration in the atmosphere, you can see that particularly over the northern hemisphere, and specially over the Arctic, we see a tremendous amount of methane being released into the atmosphere. – That was not there yet 50 years ago.
– That's right, that´s right. It was not there 50 years ago. it wasn't even there, at this sort of scale, 10 or 20 years ago. So, within the last couple of decades, we have apparently triggered the clathrate gun. Firing the clathrate gun is the event that James Hansen was particularly worried about in his book Storms of My Grandchildren. And if you look at methane levels about a month ago, atmospheric methane levels from about a month ago, there's a lot of dark red up there in the northern portion of the northern hemisphere. And that dark red indicates a lot of methane in the atmosphere. Just that one self-reinforcing feedback loop, methane bubbling out of the Arctic Ocean which is reported in the scientific literature, in Science in March 2010, that one self-reinforcing feedback loop is equivalent to 1000 to 10,000 gigatons of carbon, compared to the about 300 gigatons of carbon we burned through burning fossil fuels, so far. – Since 1850 – We know.
.. go ahead. I'm sorry. – Since 1850. From 1850 to now we burned about 300 billion tons a of carbon dioxide. – That´s right, about 300 gigatons. About 300 gigatons of carbon through burning fossil fuels. And this is considerably more than that. this is nearly 40 times, up to nearly 40 times the carbon equivalent found in the methane, just in the Arctic alone. And there's methane in the permafrost and there's methane in the Antarctic as well. So, there's methane coming from all kinds of sources. Just that one source, methane coming out the Arctic Ocean, threatens to release far more carbon equivalent then we burned by burning fossil fuels According to the authors a paper in Nature, in July 2013, a 50 gigaton burp of methane is "highly possible at anytime". So it could be we have a 50 gigaton burp that's equivalent to more than 1.000 gigatons of carbon burned by fossil fuels it's highly possible anytime. – Which is almost 3 times what we burned since we started the Industrial Revolution, within a matter of weeks or months.
– That's right. And, as reported in the in the journal literature in a paper in global policy from September 2012 "A sweep of amplifying feedback mechanisms, such as massive methane leaks from the subsea Arctic Ocean, have engaged". So, it's pretty clear, even in the very conservative scientific literature, that we have triggered a number a self-reinforcing feedback loops, and, in particular this one, runaway methane could trigger runaway greenhouse event. And, in fact, that's the conclusion of Sam Carana and Malcolm Light, both writing for the Arctic Methane Emergency Group. So if we could go to the final slide I sent you, it shows a runaway event, a polynomial or exponential curve fit to the data and extended forward, whereby we see a global average temperature of more than 4º C by 2030, and more than 10º C above baseline by 2040. We haven't had human beings on the planet at 3,5º C above baseline.
So 4º C or 10ºC above baseline… those are very large numbers. I want to read to you the conclusion Malcolm Light reached in January of this year, January 2014. He says: "The gulfstream transport rates started the methane hydrate gun firing in the Arctic in 2007, when it's energy per year exceeded 10 million times the amount of energy per year necessary to dissociate subsea Arctic methane hydrates." So, it's pretty clear at this point that we have fired the clathrate gun and that that self-reinforcing feedback loop alone takes us to uninhabitability of this planet for human beings in a relatively short period of time. – So, you're talking about something like the Permean mass extinction or the Paleocene–Eocene Thermal Maximum, a period of time where most species on earth and sea die? Including us? – That's right. – And what kind of time scale? Well, we´re human animals and so we need habitat. This isn't..
. Humans won´t go extinct because it becomes too warm and we're not able to adapt to that warm temperature, or because it becomes too cold and we´re not able to adapt. Rather, it'll come because the plants and the plankton in the ocean, plants on land and the plankton in the ocean, can't respond very quickly to the very rapid changes that are occurring. So we've already lost approximately half of the plankton from the ocean in the last few decades, at 0,85º C above baseline. So you can imagine when we get to 2 or 3 or 4 degrees C above baseline, above the beginning of the Industrial Revolution, that it's quite possible, and I would say probable, that we won't have a significant number of plankton in the ocean at all. And the same thing for land plants. We have this huge temperature swings that are going on right now. If we get up to 125, 130 degrees Fahrenheit that's sufficient to denature proteins in land plants and kill all the land plants. And they just can't adapt quickly enough.
How soon? Well, according to Carana's analysis, we get there by 2030. More than 4ºC by 2030, more than 10º C by 2040. It certainly could happen that quickly. As Albert Bartlett, long time professor emeritus from Colorado University wrote and said many times: "The greatest shortcoming of the human race is our inability to understand the exponential function." And we're beyond linear, with respect climate change, and it's difficult for us to… to wrap our minds around that, to project into the future something beyond linear. – And… and your suggestion that we could be, you and I we could be… and, in particular, people younger than us, could be the ones who actually see the end of the human race. Let me… let me come back to that right after this break. More of tonight's Conversations with Great Minds with the professor Guy McPherson. Right after this..