Who is Guy McPherson?



A former professor of ecology, Guy McPherson has attained some fame and respect among back-to-the-land “permaculture” types. I have no idea what he may or may not know about ecology, but he doesn’t know much about climate. This hasn’t prevented him from using his professorial credentials in the “permie” subculture, and what he tells the permies is that we are absolutely, irrevocably doomed.

Specifically, he believes that there are unstoppable feedbacks built into the climate system that have now triggered the system into instability. He thinks the climate will go bonkers in the way Jimi Hendrix’s guitar would howl when he held it up to the amp speaker. And he thinks it will go so thoroughly out of kilter as to kill every human alive by 2030.

It’s hard to tell why, but some people love him for it. It seems to me he is doing a lot of damage with this schtick nonetheless.

Fortunately, he is both completely out of his depth and wrong. It’s about time he got challenged by people with the scientific ammunition to stand up to him.

A good start on taking down Guy McPherson appeared recently by Scott Johnson at Fractal Planet. And one could hardly do better in a paragraph than this:

In many ways, McPherson is a photo-negative of the self-proclaimed “climate skeptics” who reject the conclusions of climate science. He may be advocating the opposite conclusion, but he argues his case in the same way. The skeptics often quote snippets of science that, on full examination, don’t actually support their claims, and this is McPherson’s modus operandi. The skeptics dismiss science they don’t like by saying that climate researchers lie to keep the grant money coming; McPherson dismisses inconvenient science by claiming that scientists are downplaying risks because they’re too cowardly to speak the truth and flout our corporate overlords. Both malign the IPCC as “political” and therefore not objective. And both will cite nearly any claim that supports their views, regardless of source— putting evidence-free opinions on par with scientific research. (In one example I can’t help but highlight, McPherson cites a survivalist blog warning that Earth’s atmosphere is running out of oxygen.)

I agree completely. McPherson is not the opposite of a denialist. He is a denialist, albeit of a different stripe. To watch him at work and to watch Tony Watts is to watch birds of a feather. Not evidence-based policy but policy-based evidence. Not part of the solution. Part of the problem.

I was wondering whether my work in “fisking” McPherson was done, but it turns out that McPherson’s article is so long and meandering that Johnson gets plenty of mileage while skipping over the part that interests me most; McPherson’s so-called points in evidence that Doom.

McPherson’s Claims to be a Scientist Fail

In one respect, credentials, McPherson trumps Watts. Apparently he once was faculty, albeit in a non-physical science.

The Ph.D. impresses some people; those of us who have jumped that hurdle know that the population of Ph.D.’s is rich with brilliance, but also rich with charlatanry. Actually anyone who has a degree must have suspected. Remember some of your more bizarre professors?

A doctorate really only proves you’re eccentric and dogged; whether you are actually talented or not remains to be seen. The proportion of talent among Ph.D.s is high, but it’s nowhere near 100%.

So we must ask whether McPherson’s claim to be a scientist based on an actual grasp of what science is and how it is conducted, or (like certain other prominent professor-bloggers of our acquaintance) whether he has merely pro forma credentials?

I say the latter.

Readers may recall that, for me, the final nail in the coffin of any prospect of taking Judith Curry seriously was her jaw-droppingly incoherent “Italian Flag” essay, her attempt to stake out some territory in the domain of climate uncertainty. It wasn’t that it was wrong. (One can disagree about matters of substance – does the wavering northern jet stream cause Arctic warming or does Arctic warming cause the wavering jet stream? One can have fruitful disagreements about matters of substance.)

The point is that making a claim that is incoherent on its face disqualifies you from active participation in science about related matters.

Now I see McPherson making a similarly baldly incompetent claim.

These feedbacks are not additive, they are multiplicative.

This makes no sense.

Now, not a lot of people interested in climate have really been exposed to the mathematics of feedback and control systems. I think I am on solid ground as an electrical engineer when I say that this claim is not just wrong, but it is meaningless, just as meaningless as Curry’s baffled confusion of measurement uncertainty with hypothesis certainty. It isn’t true. It’s not even false. It means nothing.

To the extent that feedback is a useful model, feedbacks are additive, not multiplicative. They can’t be multiplicative.

And he is doing it in such a casual off-hand way; he is clearly not trying to investigate formal concepts; he is clearly indiffferent toward them. He’s just trying to impress you. Like the denialists, he makes no effort to convince actual experts. Rather he treats expertise with such contempt that he feels free to pose as an expert on a matter on which he has no expertise.

It is fine for a scientist to know nothing about reasoning under uncertainty, but they would be well-advised not to testify to congress on statistics. It is fine for a scientist to know nothing about feedback and control, but they presumably shouldn’t be telling people to quit their day jobs as a consequence of his reasoning about it.

An Attempt to Explain

Suppose, for instance, that we consider water vapor feedback, which is a positive feedback. Now let’s instead consider northern hemisphere water vapor feedback and southern hemisphere feedback as separate terms. They really have to give the same result, no? Systems can be parsed into components in lots of ways that are consistent; the same system can’t act two different ways depending on how you analyze it. If that is the case, your analysis is wrong.

You can always call two feedbacks one feedback with a more complicated formula. But if they are multiplicative you get a nasty problem when the input goes negative. In that case, the output will be negative if the number of feedbacks you are using is odd and positive if the number of feedbacks is even. Just the tiniest multiplicative feedback would totally flip the response of the whole system on its head. Essentially this is a mathematical monster with no basis in any real physical system.

Okay, so this is a minor technical point, perhaps. McPherson just threw that sentence off in passing. If he decides to take me seriously, it’s easy to imagine him erasing it (though it’s still in the copy of the article I stored in webcite). “Not worth the controversy,” he may think.

But I’m not here to argue the point. I’m here to point out the type of mentality required to make an error like this. An entire article intended to establish bona fides as an expert on feedback making a claim that someone who knows something about feedback can instantly dismiss as worse than wrong, as confused and dreamlike, as Italian-flag-like.

So How Do We Think About Feedback?

Much of the rich mathematics of feedback applies only to linear systems and offers relatively limited insight for nonlinear systems, so only the rudiments of the idea can be imported into climate science. It suffices for our purposes to consider a scalar system, i.e., one where the quantities of interest can be expressed by a single number. We envision a very crude model wherein global radiative forcing drives temperature, which in turn drives a vast array of phenomena, some of which (the feedbacks) in turn modify radiative forcing.

It is important to understand that the way we draw boundaries in the system are arbitrary; whether they form a useful model of the system or not depends on our skill in identifying components and thinking consistently about them.

The most prominent is the “water vapor feedback”, which in some circles is considered controversial. Suppose there is some forcing, be it solar or greenhouse-gas forcing. All else equal, the temperature of the surface is calculated from a simple energy balance and the Stefan-Boltzmann law. But all else is NOT equal, as the perturbed surface, if cooled, will evaporate less water; conversely, if heated, will evaporate more. And water vapor is a greenhouse gas. This creates an additional forcing.

To make matters more interesting still, that additional forcing creates a further temperature perturbation, which causes still greater shift in water vapor. This loop is sometimes unstable and sometimes stable – we’ll consider it further below.

Note, though, that “water vapor” is a “feedback” if and only if we consider surface evaporation somehow outside the rest of the climate system. We can easily do that in a computer simulation. We can “turn off” water vapor feedback by having evaporation respond to the unperturbed climate, and watch the difference. If we consider the climate system to include surface evaporation, that is, in the intuitive way, water vapor is just a part of the system and there isn’t a “feedback”. Feedback in natural systems is a conceptual tool, not a real process distinction.

Nevertheless, it is possible for real systems to become unstable, and it is often useful to draw on the concept of the feedback loop to understand how. Consider, for example, that Venus is far hotter than one would expect the Earth to be if moved to Venus’ orbit. This is almost certainly because of a “runaway greenhouse effect” that boiled off Venus’ ocean.

(Chris Colose explains in detail how this works; it actually depends on the nonlinearity of the evaporation with temperature).

How does this tie into the feedback concept?

A Negative Feedback

Despite the vernacular usage, “negative feedback” is usually a good thing. Systems with negative feedback are typically very stable. If the system gets too “hot” (we can be referring to any quantity, not just temperature, for example, voltage), a negative feedback cools it down, and if it gets too “cool”, negative feedback warms it up. This allows the system to maintain a set point. A simple everyday example of such a system is a thermostatically controlled temperature.

Positive Feedback

The situation with positive feedback is more complicated.

The classic example of positive feedback of course involves a live amplified microphone or guitar. The amplified sound from the speaker re-excites the microphone membrane or guitar string, which then plays louder than it would have had the speaker been located in a separate room. At a certain level of amplification (if the instrument is close enough to the speaker) the system starts to go unstable, and tries to blast your eardrums. Essentially if the loop isn’t broken the system will put out as much sound as the components are capable of. They may be limited by the amplifier or by the speaker, but one of these will be pushed to its limits. As will everybody in the room. (And it’s the clever flirting with those limits that made Jimi Hendrix the genius of feedback as well as of the guitar that he was).

It’s just such a runaway feedback loop that McPherson wants us to fear: the greenhouse gases causing warming causing more greenhouse gases causing more warming until everything spins out of control. It sounds plausible. But is it?

Well, first of all we can take note of the fact that greenhouse gases have gone up far above the anticipated levels in the past, not so far in the past that the sun’s output was appreciably different or the land configuration was dramatically changed. And there’s no sign of runaway feedback – after all we are still here and have not yet suffered the fate of Venus.

It’s true that what we are doing now is enormously ecologically stressful, primarily because the rate of change is so rapid. And it’s possible that there will be some carbon feedback from that. But enough to go unstable?

Notice please that you have been in rooms with microphones and speakers many times. There are complicated acoustic tricks to reduce the positive feedback; highly directional microphones help the most. But they only reduce the positive feedback. They do not eliminate it. For a system to be unstable, positive feedback is not enough. The feedback has to be SUFFICIENT to cause instability.

The upshot comes down to a very simple rule. If the feedback is enough to double the input, the system is unstable. If it is even slightly less, there will be a huge net amplification but it will eventually stabilize. If it is much less than double, the system amplifies only modestly. A feedback factor of 0.5, that is, increasing the signal 1.5 times (the original plus half) results in a final amplification of double. The rule is simple: for a feedback of F between 0 and 1, the amplification is 1/(1-F). That’s 1 + F + F*F + F*F*F + …, a convergent infinite geometric series as you may recall from first year calculus. This comes from going round and round the feedback loop. For F equal to or greater than 1, the sum does not converge.

Criteria for a McPherson Catastrophe

We will define a McPherson Catastrophe as a feedback sufficient to go unstable by 2030.

So let’s consider what would be needed for that to happen. For one thing, as explained above, the feedback factor has to be greater than 1; that is, a single application of all the feedbacks needs to double the original greenhouse forcing.

Secondly, it has to operate quickly enough to go several times around the loop in the 16 years remaining; otherwise it doesn’t have time to kill us by 2030.

You may object to this on the grounds that it has already had a century or so of anthropogenic input; but anything that slow is already doing us almost as much damage as it is going to do by 2030. So we really need feedbacks with time scales on the order of not more than 4 or 5 years; really phenomena that operate within weeks would be “better” for McPherson’s claim, i.e., worse.

Thirdly, it has to not have a cap. For example, ice albedo feedback does give the system a swift kick into a new climate, but it doesn’t actually cause a runaway instability. That is because there is only so much sea ice to melt. Once it is gone, that feedback stops. It’s just a one-time effect.

Finally, the feedback or feedbacks that meet these criteria have to be unmatched by negative, ameliorating feedbacks of any kind. Now of course, McPherson has no more interest in ameliorating feedbacks than Watts does in exacerbating feedbacks, but claiming that none exist makes little sense. For an obvious example, the system sensitivity to CO2 declines slowly with increasing CO2 due to radiative physics. This doesn’t matter much in the real world, but in a McPherson scenario could be considered as an ameliorating, negative feedback.

So we can dismiss many of his claims as “not fast enough”; of the remainder we need to consider whether they are in aggregate deep enough to account for, say, a quadrupling of the present day forcing (about 8 watts per square meter forcing, which would be nasty and possibly collapse-inducing, but which we will generously call enough for a human extinction event) and intense enough (an open loop feedback doubling the input).

OK, now let’s look at his list.

McPherson’s List

1. Methane hydrates are bubbling out the Arctic Ocean (Science, March 2010). According to NASA’s CARVE project, these plumes were up to 150 kilometers across as of mid-July 2013. Global-average temperature is expected to rise as much as 4.5 C by 2030 and 10 C by 2039 based solely on methane release from the Arctic Ocean, according to Sam Carana’s research (see especially Image 24). WhereasMalcolm Light’s 9 February 2012 forecast of extinction of all life on Earth by the middle of this century appears premature because his conclusion of exponential methane release during summer 2011 was based on data subsequently revised and smoothed by U.S. government agencies, subsequent information — most notably from NASA’s CARVE project — indicates the grave potential for catastrophic release of methane. (I doubt industrial civilization manages to kill all life on Earth, although that clearly is the goal.) Catastrophically rapid release of methane in the Arctic is further supported by Nafeez Ahmed’s thorough analysis in the 5 August 2013 issue of the Guardian as well as Natalia Shakhova’s 29 July 2013 interview with Nick Breeze (note the look of abject despair at the eight-minute mark). In early November 2013, methane levels well in excess of 2,600 ppb were recorded at multiple altitudes in the Arctic. Later that same month, Shakhova and colleagues published a paper inNature Geoscience suggesting “significant quantities of methane are escaping the East Siberian Shelf” and indicating that a 50-billion-tonne “burst” of methane could warm Earth by 1.3 C. Such a burst of methane is “highly possible at any time.” By 15 December 2013, methane bubbling up from the seafloor of the Arctic Ocean had sufficient force to prevent sea ice from forming in the area.

Well, this is the big one. It links McPherson to the highly dubious alarmist Arctic Methane Emergency Group. But it’s nonsense. Chris Colose put this to bed, and efforts to revive this after he did so have been empty handwaving. See also Stoat. As readers here will recall, I, along with Chris Colose and Gavin Schmidt, managed to talk Nafeez down from this position, so that hardly counts. Verdict: MUCH TOO SLOW

2. Warm Atlantic water is defrosting the Arctic as it shoots through the Fram Strait (Science, January 2011).

We have to include this as sea ice reduction. This will have many consequences, but as a feedback mechanism it’s highly limited. The fraction of solar input impinging on the Arctic is very small compared to the whole earth. The area of Arctic ice is, depending on the season, as much as 8,000,000 square kilometers, and the area of the earth is 510,000,000, so even if the Arctic got its fair share and it went from white to black year round that would cap its contribution at less than 1.5%; however, it only gets sunshine for half the year, and most of that time the sea ice is extensive. There is a worry that September sea ice will go away but no such worry about March sea ice. So we are really talking about July and August, so that’s about a sixth of the year. And then the low sun angle will multiply that by about sin(15 degrees) so together a factor of about 24; throw in another factor of 2 because oblique incidence on water is reflective, and we are talking a radiative fraction of .015/50 = .0003, or about a tenth of a watt per square meter. Verdict: TOO SMALL

3. Siberian methane vents have increased in size from less than a meter across in the summer of 2010 to about a kilometer across in 2011 (Tellus, February 2011)

This is simply a crock. The largest observed vent in 2011 is a km across; it had not been observed before. There is no claim that it is new and no evidence to that effect. This is waved around by the Arctic methane people as if it were a vast maelstrom of methane, choking the air. In fact it is a barely detectable region containing a few methane bubbles. That is why it had not been detected prior to 2011. Verdict: IRRELEVANT AND MISLEADING

4. Drought in the Amazon triggered the release of more carbon than the United States in 2010 (Science, February 2011). In addition, ongoing deforestation in the region is driving declines in precipitation at a rate much faster than long thought, asreported in the 19 July 2013 issue of Geophysical Research Letters.

In this specific case, though, focusing on the drought of 2010 is a cherry pick. The Amazon has recovered since then. That said, this was the second 100-year drought in five years, which does lean toward indicating some climate change. But is the entire Amazon going to die by 2030? Hardly. Suppose it did? What is the carbon inventory of the Amazon? Well, the carbon inventory of all the world’s forests is about half a GT. So suppose ALL THE TREES SUDDENLY DIED EVERYWHERE. The carbon in the atmosphere would about double. Once. Would this kill us? Maybe. I would hate to see such a world. But will we see it by 2030? That’s kind of crazy, especially since some forests are expanding. Anyway, let’s ballpark the Amazon at a tenth of the world’s biomass and pessimistically call the damage from drought as about a tenth of that by 2030. That adds 1% to the carbon inventory of the atmosphere/ocean system, or about 0.5% to the atmosphere. So this looks like maybe a 200th of a doubling, or about 0.02 watts. Oh Hell. Let’s make it ten times worse. 0.2 Watts. Enough to make a difference, but not cataclysmic. Anyway, let’s all remember that the biosphere as a whole is still a carbon sink, not a source. Verdict: Scary and nasty but not huge by 2030. TOO SLOW

5. Peat in the world’s boreal forests is decomposing at an astonishing rate (Nature Communications, November 2011)

“Astonishing?” Not a very good number to work with and a pretty shabby reference. I am having trouble finding much about this. There are some hundreds of GT of peat in the world, mostly in Canada and Russia, enough to make a very substantial difference if it ALL goes up. Again, global land carbon inventory is going up, so loss of peat is not really showing up yet. So, it’s hard to see this mattering by 2030. I am guessing the relevant article is this one. I haven’t looked at the article, but the abstract says “interactions between peatland drainage and fire are likely to cause long-term carbon emissions to far exceed rates of carbon uptake, diminishing the northern peatland carbon sink”. This is indeed a climate feedback and potentially a large one, but it does mention the “long term”. Verdict: Again, scary and nasty but not huge by 2030. TOO SLOW

6. Invasion of tall shrubs warms the soil, hence destabilizes the permafrost (Environmental Research Letters, March 2012)

Now this one is fascinating. After all the talk of dying trees, here he is complaining about expanding trees. Let’s think about this – more trees are darker, causing warming, and fewer trees release carbon, causing warming. But more trees absorb carbon, causing cooling, and fewer trees increase albedo, causing cooling. Could it be that the biotic balance is about neutral? That the sign is unknown? My understanding is that this is the case. Now of course we need to look at how fast this is happening. Again, a real scientist would have provided a real reference. I think he means this one. Here’s the concluding paragraphs: This study, and that of Lawrence et al (2011b), prescribed

substantially different distributions of hypothetical shrub area

increase. Despite the differences, both studies indicate that

the warming response to a large-scale expansion of shrubs

in the NHL could overwhelm the soil cooling effect due

to shading (Blok et al 2010, Yi et al 2007), leading to

increased rather than decreased vulnerability of permafrost.

Although not analyzed here, these physical feedbacks would

likely impact ecosystem biogeochemical processes (e.g., soil

decomposition, plant growth) controlling the exchanges of

carbon between soil and atmosphere To summarize, our study highlights the need to account

for the expansion, stature, and phenology of invading

vegetation to improve climate prediction in the NHL regions.

This study also highlights the need of augmenting the number

of CCSM arctic and sub-arctic shrub types, improving their

representation of fractional cover and height, and treating the

shrub expansion more realistically with a dynamic vegetation

component in the model. Ho hum, right? Huge regional effects, but globally it may be carbon neutral (increased shrubs compensating for decaying permafrost) and temperature neutral (no direct radiative forcing, rearranging energy). Verdict: Preliminary result, interesting, sign of effect uncertain, impact on large scale unclear. TOO SLOW AND TOO SMALL.

7. Greenland ice is darkening (The Cryosphere, June 2012)

Verdict: Referencing the Guardian again!? Anyway, sure, this is a problem for sea level rise, but tiny in the global scheme of things, much smaller than the Arctic sea ice decline. TOO SMALL.

8. Methane is being released from the Antarctic, too (Nature, August 2012). According to a paper in the 24 July 2013 issue of Scientific Reports, melt rate in the Antarctic has caught up to the Arctic and the West Antarctic Ice Sheet is losing over 150 cubic kilometres of ice each year according to CryoSat observations published 11 December 2013, and Antarctica’s crumbling Larsen B Ice Shelf is poised to finish its collapse, according to Ted Scambos, a glaciologist at the National Snow and Ice Data Center at the annual meeting of the American Geophysical Union. Further confirmation of large methane releases is revealed by noctilucent clouds over the southern hemisphere from 21 November 2013 to 6 December 2013.

Groan. What an incoherent mess. This is two points hopelessly garbled together. We will ignore the stuff related only to sea level rise, as they will not contribute to a near-term extinction. That leaves “Further confirmation of large methane releases is revealed by noctilucent clouds over the southern hemisphere from 21 November 2013 to 6 December 2013.” And what’s our reference for that? Sam Carana’s blog! OK, if you are going to lose sleep over that, let me reassure you. Occasional surface methane readings a few per cent above normal don’t matter. VERDICT: UTTER BILGE

9. Russian forest and bog fires are growing (NASA, August 2012), a phenomenon consequently apparent throughout the northern hemisphere (Nature Communications, July 2013). The New York Times reports hotter, drier conditions leading to huge fires in western North America as the “new normal” in their 1 July 2013 issue. A paper in the 22 July 2013 issue of the Proceedings of the National Academy of Sciences indicates boreal forests are burning at a rate exceeding that of the last 10,000 years.

OK, serious business, but like the Amazon, not about to kill us right away. Verdict: TOO SMALL AND TOO SLOW

10. Cracking of glaciers accelerates in the presence of increased carbon dioxide(Journal of Physics D: Applied Physics, October 2012)

So? Verdict: A sea-level rise issue. Important but not extinction-related. IRRELEVANT.

11. The Beaufort Gyre apparently has reversed course (U.S. National Snow and Ice Data Center, October 2012)

So? No relevance proposed. Verdict: IRRELEVANT

12. Exposure to sunlight increases bacterial conversion of exposed soil carbon, thus accelerating thawing of the permafrost (Proceedings of the National Academy of Sciences, February 2013)

A certain amount of hype at the link. I smell a press officer. Here’s the actual abstract. Maybe this is serious but it is TOO SLOW. See this image.

13. The microbes have joined the party, too, according to a paper in the 23 February 2013 issue of New Scientist

Well of course it’s bacteria, you doorknob. Where did you think the methane comes from? From the cited (popular press) article: As for the methane that could be released into the atmosphere, Schuur estimates that emissions will be equivalent to between 160 and 290 billion tonnes of carbon dioxide. That sounds like a lot, but is little compared to the vast amount humans are likely to emit, says Lenton. “The signal’s going to be swamped by fossil fuel [emissions].” VERDICT: TOO SMALL

14. Summer ice melt in Antarctica is at its highest level in a thousand years: Summer ice in the Antarctic is melting 10 times quicker than it was 600 years ago, with the most rapid melt occurring in the last 50 years (Nature Geoscience, April 2013). Although scientists have long expressed concern about the instability of the West Atlantic Ice Sheet (WAIS), a research paper published in the 28 August 2013 ofNature indicates the East Atlantic Ice Sheet (EAIS) has undergone rapid changes in the past five decades. The latter is the world’s largest ice sheet and was previously thought to be at little risk from climate change. But it has undergone rapid changes in the past five decades, signaling a potential threat to global sea levels. The EAIS holds enough water to raise sea levels more than 50 meters.

Sea level again. A very big deal, but not a species breaker. VERDICT: IRRELEVANT.

15. Increased temperature and aridity in the southwestern interior of North America facilitates movement of dust from low-elevation deserts to high-elevation snowpack, thus accelerating snowmelt, as reported in the 17 May 2013 issue of Hydrology and Earth System Sciences.

Southwestern drought increases albedo, so globally is a negative feedback. Again, nasty business. Not a destabilizing feedback at all, though. VERDICT: NEGATIVE FEEDBACK

16. Floods in Canada are sending pulses of silty water out through the Mackenzie Delta and into the Beaufort Sea, thus painting brown a wide section of the Arctic Ocean near the Mackenzie Delta brown (NASA, June 2013)

So? VERDICT: IRRELEVANT

17. Surface meltwater draining through cracks in an ice sheet can warm the sheet from the inside, softening the ice and letting it flow faster, according to a study accepted for publication in the Journal of Geophysical Research: Earth Surface (July 2013).

It appears a Heinrich Event has been triggered in Greenland. Consider the description of such an event as provided by Robert Scribbler on 8 August 2013:

In a Heinrich Event, the melt forces eventually reach a tipping point. The warmer water has greatly softened the ice sheet. Floods of water flow out beneath the ice. Ice ponds grow into great lakes that may spill out both over top of the ice and underneath it. Large ice damns (sic) may or may not start to form. All through this time ice motion and melt is accelerating. Finally, a major tipping point is reached and in a single large event or ongoing series of such events, a massive surge of water and ice flush outward as the ice sheet enters an entirely chaotic state. Tsunamis of melt water rush out bearing their vast floatillas (sic) of ice burgs (sic), greatly contributing to sea level rise. And that’s when the weather really starts to get nasty. In the case of Greenland, the firing line for such events is the entire North Atlantic and, ultimately the Northern Hemisphere.

Two distinct items. Garbled again. The first is about sea level rise, and so IRRELEVANT to near-term extinction. The second is wild speculation on a blog. Note that events of this class appear to be associated with multi-century cold intervals in a warming period. Heinrich events certainly would count as a NEGATIVE FEEDBACK if one were to take that claim seriously for some peculiar reason.

18. Breakdown of the thermohaline conveyor belt is happening in the Antarctic as well as the Arctic, thus leading to melting of Antarctic permafrost (Scientific Reports, July 2013)

Maybe, but the amount of Antarctic permafrost exposed to the air by 2030 is trivial on a global scale. Verdict: TOO SMALL.

19. Loss of Arctic sea ice is reducing the temperature gradient between the poles and the equator, thus causing the jet stream to slow and meander. One result is the creation of weather blocks such as the recent very high temperatures in Alaska. As a result, boreal peat dries and catches fire like a coal seam. The resulting soot enters the atmosphere to fall again, coating the ice surface elsewhere, thus reducing albedo and hastening the melting of ice. Each of these individual phenomena has been reported, albeit rarely, but to my knowledge the dots have not been connected beyond this space. The inability or unwillingness of the media to connect two dots is not surprising, and has been routinely reported (recently including here with respect to climate change and wildfires) (July 2013)

This isn’t a feedback, it’s a kvetch. Can you leave the whole systems modeling to people with whole systems models please? VERDICT: REPEATS PREVIOUS CLAIMS, REDUNDANT

20. Arctic ice is growing darker, hence less reflective (Nature Climate Change, August 2013)

We dealt with this in #2 above. Verdict: TOO SMALL

21. Extreme weather events drive climate change, as reported in the 15 August 2013 issue of Nature (Nature, August 2013)

The cited article explicitly says that this will be a concern by the end of the century. Verdict: TOO SLOW

22. Ocean acidification leads to release of less dimethyl sulphide (DMS) by plankton. DMS shields Earth from radiation. (Nature Climate Change, online 25 August 2013). Plankton form the base of the marine food web, and are on the verge of disappearing completely, according to a paper in the 17 October 2013 issue of Global Change Biology.

You won’t find me saying happy things about the state of the ocean. This is intrinsically tragic. Also fisheries will decline sharply, but fish just aren’t that important to the human diet. Massive extinctions in the sea, but nothing justifies a near term human extinction claim. VERDICT: IRRELEVANT

23. Sea-level rise causes slope collapse, tsunamis, and release of methane, asreported in the September 2013 issue of Geology. In eastern Siberia, the speed of coastal erosion has nearly doubled during the last four decades as the permafrost melts.

Yeah, but there’s still no sign of Siberian methane in the observations. Give it a rest. VERDICT: REPEATS #1

24. Rising ocean temperatures will upset natural cycles of carbon dioxide, nitrogen and phosphorus, hence reducing plankton (Nature Climate Change, September 2013)

same answer as #22: You won’t find me saying happy things about the state of the ocean. This is intrinsically tragic. Also fisheries will decline sharply, but fish just aren’t that important to the human diet. Massive extinctions in the sea, but nothing justifies a near term human extinction claim. VERDICT: IRRELEVANT

25. Earthquakes trigger methane release, and consequent warming of the planet triggers earthquakes, as reported by Sam Carana at the Arctic Methane Emergency Group (October 2013)

Sam Carana has not submitted his theories to peer review; the speculative time scale of climate-seismic coupling, if real, is very long. VERDICT: MUCH TOO SLOW

26. Small ponds in the Canadian Arctic are releasing far more methane than expected based on their aerial cover (PLoS ONE, November 2013)

We’ve pretty much covered the tundra methane already. A very big deal in the long run, but TOO SMALL AND TOO SLOW for a big impact by 2030.

27. Mixing of the jet stream is a catalyst, too. High methane releases follow fracturing of the jet stream, accounting for past global-average temperature rises up to 16 C in a decade or two (Paul Beckwith via video on 19 December 2013).

Beckwith. Sigh. Did he publish that? VERDICT: EXTREMELY DUBIOUS

28. Arctic drilling was fast-tracked by the Obama administration during the summer of 2012

OK, an economic feedback of sorts. I guess. I wish we were finding ways to decease demand. But does this increase demand? If not, it is NOT A FEEDBACK

29. Supertankers are taking advantage of the slushy Arctic, demonstrating that every catastrophe represents a business opportunity, as pointed out by Professor of journalism Michael I. Niman and picked up by Truthout (ArtVoice, September 2013)

You’re really putting me on. You call yourself a scientist? Yeah this is disturbing, but how does it make matters worse even on the teeny tiny scale that it happens on? As far as I can tell the whole point would be to save on fuel. VERDICT: LUDICROUS

Other Big McPherson Mistakes

As I mentioned above, McPherson totally ignores any ameliorating feedbacks.

It’s also an implicit belief of the McPhersonite community that every single nuclear site will “go Chernobyl” immediately after civilization collapses. Not one will be shut down in anything like a safe fashion. And although the mortality from Chernobyl was on the order of 20,000, mostly cancer cases spread over decades, 400 of these would apparently kill us all instantaneously. I leave the arithmetic to the reader.

As Scott Johnson pointed out, there’s plenty of this to go around. I need to stop now.

Enough of this nonsense. Ph.D. or not, this is manipulative BS, not science.

Why McPherson wants to scare the daylights out of people escapes me. It is not clear to me what his motivation is. I doubt he is in the employ of the Koch brothers, but he certainly demoralizes people who might otherwise have been active, so he’s not doing us any favors. He may have more cultural affinity with environmentalists than with oil oligarchs, but he’s doing them a lot more good than he’s doing us.

UPDATES

My comments from the Facebook thread on the Global Warming Fact of the Day group.

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Ed Norris I’ve made it to the section on the Siberian ice sheet. I remember reading of this in the summer or fall, and that the total methane buried and frozen there could cause 1/2 a degree C of rise all by itself if released. Is there any reliable data on how much there is under there, and what kind of temperature rises it would take to release all of it? Is it now thought to be a very slow protracted process, or do we simply not know?





Some of these things are genuinely scary, but none of them are 15-years scary, certainly not 15-year-timescale-destabilizing in the sense of an unstable feedback. Michael Tobis There is no mechanism to warm it all up all at once, it fails just as with the Shakhova mechanism because there is no way it can happen all at once.Some of these things are genuinely scary, but none of them are 15-years scary, certainly not 15-year-timescale-destabilizing in the sense of an unstable feedback. === Patrick Walden … I have been told by Andrew Weaver, a climate scientist from UVIC who specializes in climate models, that Arctic methane has not exactly been incorporated into climate change models (I hope I got that right). Michael Tobis Emissions, natural or otherwise, are an *input* into what are usually called “climate models”, so no, they are not included as a feedback.



This will not be the case in the new Earth System Models coming online. I have my doubts about the validity of those ESMs, which couple geochemistry and climate, but that’s for another time and place.



There are many other sorts of models used in science and surely there is a sense in which Arctic methane is modeled somewhere, but you wouldn’t call it a “climate model”.



The linked article makes a complete hash of the methane business.



“Supersaturated” means that the water column is a methane source; it doesn’t say by how much. No evidence has been presented that the Arctic methane source has appreciably increased over preindustrial background levels, handwaving and frowning notwithstanding.



The methane inventory in the Arctic and at the sea margin is indeed enormous. But it is in places that do not warm up abruptly. If we warm the planet up enough to destabilize them, the current expectation is that they will leak out over millennia, which would not be anywhere near as bad as the abrupt release that some people insist on fantasizing about. === McPherson himself, quoted by Colm McGinn:

Guy McPherson shared a link via Pauline Panagiotou Schneider.

16 hours ago

Realizing it’s hopeless doesn’t make everybody roll over and die. Some people, including Tim DeChristopher, act!



TIM: Yeah. I met Terry Root, one of the lead authors of the IPCC report, at the Stegner Symposium at the University of Utah. She presented all the IPCC data, and I went up to her afterwards and said, “That graph that you showed, with the possible emission scenarios in the twenty-first century? It looked like the best case was that carbon peaked around 2030 and started coming back down.” She said, “Yeah, that’s right.” And I said, “But didn’t the report that you guys just put out say that if we didn’t peak by 2015 and then start coming back down that we were pretty much all screwed, and we wouldn’t even recognize the planet?” And she said, “Yeah, that’s right.” And I said: “So, what am I missing? It seems like you guys are saying there’s no way we can make it.” And she said, “You’re not missing anything. There are things we could have done in the ’80s, there are some things we could have done in the ’90s—but it’s probably too late to avoid any of the worst-case scenarios that we’re talking about.” And she literally put her hand on my shoulder and said, “I’m sorry my generation failed yours.” That was shattering to me.



TERRY: When was this?



TIM: This was in March of 2008. And I said, “You just gave a speech to four hundred people and you didn’t say anything like that. Why aren’t you telling people this?” And she said, “Oh, I don’t want to scare people into paralysis. I feel like if I told people the truth, people would just give up.” And I talked to her a couple years later, and she’s still not telling people the truth. But with me, it did the exact opposite. Once I realized that there was no hope in any sort of normal future, there’s no hope for me to have anything my parents or grandparents would have considered a normal future—of a career and a retirement and all that stuff—I realized that I have absolutely nothing to lose by fighting back. Because it was all going to be lost anyway.



Interview: Tim DeChristopher | Terry Tempest Williams | Orion Magazine

www.orionmagazine.org Michael Tobis DeChristopher quotes Terry Root: “, “You’re not missing anything. There are things we could have done in the ’80s, there are some things we could have done in the ’90s—but it’s probably too late to avoid any of the worst-case scenarios that we’re talking about.”



I am just about 100% sure this is misremembered. Any scientist would say “it’s probably too late to avoid some of the consequences we are talking about”.



We said in Copenhagen “last chance to avoid 2 C”, and it was. At least 2 C is now coming unless we got some of the science wrong or unless we do something drastic. But the window to avoid 2.5 C is still open, and if that one shuts we get to avoid 3 C. These get progressively much worse.



Where social collapse cuts in is a good question, and it’s contingent on many things, not just climate. Your guess is as good as mine or McPherson’s on that. But the risk of collapse goes up rapidly with temperature – pretty much everybody agrees on that.



Extinction is another matter. I cannot imagine literal human extinction due to climate change at less than 10 C and that would take continued idiocy for another century or more to achieve.



The sooner we come to our senses the better. These problems are very serious and we are making very bad decisions out of habit. But “probably too late to avoid any of the worst case scenarios”? No, and I’m pretty sure Dr Root did not say that. Michael Tobis Orion magazine link is http://www.orionmagazine.org/index.php/articles/article/6598



Very moving interview, and I believe the apology was real. For what it’s worth, I am a little younger than Terry Root, but I apologize too. We failed to get the message across. We did not expect malicious organized opposition, and probably would not have known how to deal with it even if we had expected it.



But “too late to avoid any of the worst-case scenarios” is just not how any scientist worth her salt talks.



Google search shows that this is widely requoted, so it matters. === Colm McGinn Reading your blog (and yeah, really good), it strikes me that Guy McPherson means something different from your usage of words such as ‘multiplicative’ and ‘additive’, not to mention ‘feedback’. Have to think more on it. Michael Tobis any use of “multiplicative” that doesn’t literally involve multiplying is misleading and pretentious, in my opinion

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Peter Pitchford Its all very well and good to look at the various reports and opine that they add up or don’t add up to an “exponential curve upwards”. But are there any studies that actually add up the “number of amplifying feedbacks” that are known to effect the curve? I’m not asking for definitive proof or anything of the sort, just any kind of ballpark figures scribled on the back of a napkin would be nice, even if its totally wrong. I may be missing something obvious, but I just haven’t seen anything like that anywhere. Extra points if you can show (with numbers) how Earth could possibly become Venus by 2096. March 14 at 7:16pm · Like Ed Norris I asked for the same thing. But I do know Hansen and a good number of others have shown that a runaway greenhouse effect is not possible on Earth, or at least not remotely likely. Not much consolation if it turns out to “only” be 10C of rise by 2150 or something like that. March 14 at 7:33pm · Like · 2



I think there are reasons other than those in my 29 responses to be confident that the climate system isn’t close to instability. Basically if we were 16 years shy of doom we’d be seeing more signs of it than we do. But on longer time scales the phenomenology is very hard to characterize.



But I think climatology is somewhat secondary.



By how bad can it get, I think we really mean, at what point does modern civilization collapse. By collapse we mean a mortality driven population decline – we start dying faster than we can replace ourselves because some critical resource becomes unavailable. (Note that this is well shy of extinction.)



And in this regard, climate is not the only issue. There are other ways we can wipe ourselves out. War and revolution, financial instability, diseases arising from overpopulation, badly designed artificial intelligence, these are all plausible risks in the future that didn’t exist in the past. The dominant ideology of our time seems particularly ill-suited to coping with these things.



At some point. if we remain stupid, we will go into a steep enough economic decline that mortality will drive the population down, and it’s likely the decline will accelerate. It is very hard to say when. It’s sort of pointless to place bets because there is little likelihood of collecting. I am turning 60 this year and do not expect to live to see it. If I were under 30, I would be worried.



On the other hand, I WAS worried when I WAS under 30, and so far we have avoided the crash that I expected.



Climate will probably play a significant part in whatever goes wrong if something does. But if climate goes wrong, it will mean we have still failed to come to terms with our actual predicament.



We are billions of monkeys on a rock hurtling through space. There is, as the T shirt goes, No Planet B. If we continue to act like a bunch of “countries” with “borders” to the extent that we ignore what is really happening, the prognosis isn’t good.



OK, OK, if I have to bet on the scenario of stupid monkeys staying stupid until a mortality-driven population decline starts, chastened by the refuted pessimism of the 1960s, I would still give even money on decline starting before, hmm, 2080.



I have no expectation that humans will go literally extinct on anything short of a cosmic timescale. But a lot of unnecessary suffering could be ahead. Michael Tobis It’s really difficult to answer the question of “how bad can it get by when if we continue to be stupid about it”. There are two reasons this is difficult. One is that carbon (and to a lesser extent methane) feedbacks are poorly understood.I think there are reasons other than those in my 29 responses to be confident that the climate system isn’t close to instability. Basically if we were 16 years shy of doom we’d be seeing more signs of it than we do. But on longer time scales the phenomenology is very hard to characterize.But I think climatology is somewhat secondary.By how bad can it get, I think we really mean, at what point does modern civilization collapse. By collapse we mean a mortality driven population decline – we start dying faster than we can replace ourselves because some critical resource becomes unavailable. (Note that this is well shy of extinction.)And in this regard, climate is not the only issue. There are other ways we can wipe ourselves out. War and revolution, financial instability, diseases arising from overpopulation, badly designed artificial intelligence, these are all plausible risks in the future that didn’t exist in the past. The dominant ideology of our time seems particularly ill-suited to coping with these things.At some point. if we remain stupid, we will go into a steep enough economic decline that mortality will drive the population down, and it’s likely the decline will accelerate. It is very hard to say when. It’s sort of pointless to place bets because there is little likelihood of collecting. I am turning 60 this year and do not expect to live to see it. If I were under 30, I would be worried.On the other hand, I WAS worried when I WAS under 30, and so far we have avoided the crash that I expected.Climate will probably play a significant part in whatever goes wrong if something does. But if climate goes wrong, it will mean we have still failed to come to terms with our actual predicament.We are billions of monkeys on a rock hurtling through space. There is, as the T shirt goes, No Planet B. If we continue to act like a bunch of “countries” with “borders” to the extent that we ignore what is really happening, the prognosis isn’t good.OK, OK, if I have to bet on the scenario of stupid monkeys staying stupid until a mortality-driven population decline starts, chastened by the refuted pessimism of the 1960s, I would still give even money on decline starting before, hmm, 2080.I have no expectation that humans will go literally extinct on anything short of a cosmic timescale. But a lot of unnecessary suffering could be ahead. === Patrick Walden Rex Tillerson, head of Exxon, now admits global warming is happening. However he does not recommend cutting off burning fossil fuels, he recommends that we adapt to global warming. That way we can have our cake and eat it too. Perhaps we can suggest he pay for the adaptation. 22 hours ago · Like · 7 Michael Tobis If you find yourself in a hole the first thing to do is stop digging. === Jack Wolf I’m not at the doctorate level like Guy McPherson, but I’ve been a field scientist for 30 years now. All the changes I see in our environment tell me that Guy is correct in his observations. And, the statement that he is zero for 29 is ridiculous. Michael Tobis must have blinders on because the Arctic is indeed a positive feedback, as is permafrost thaw, glaciers melt, forest death, increasing soil temperature and even the tectonic plates. You know something up when Ohio starts having the shakes in the morning let alone the 200% increase in geophysical activity. And, even closer to home, I just have to look out my window and see my dying junipers and cedars to know he is correct. Or drive the PA Turnpike to see the growth in forest die back. And, Paul Beckwithis correct in that the change is quite abrupt. So, I suggest you hold on to your hat, Michael, because events are proving you wrong. Michael Tobis The Arctic is certainly a positive feedback; as I’ve tried to explain it is not a sufficient positive feedback to cause extinction by 2030. === Jean Mcmahon A lot of insufficient feedbacks would add up to a really big feed back..that is not addressed in the writing of Michael Tobias or the IPCC consensus papers Michael Tobis You really have to find feedbacks that operate on a feedback time of less than five years or so and total to doubling the input, as I explained.



Nothing McPherson has listed comes close. Some of them are so woefully off base that he does not seem to to be thinking about this quantitatively. It is pretty clear he is handwaving.



To the claim that he might be right by accident I respond that there is no sign of feedbacks that are fast enough and severe enough in the observations – if anything matters are progressing a bit slower than anticipated on the global scale.



This is not to say that regional impacts are all proceeding slowly; I would agree with those who say these are happening faster than expected. But those don’t form a basis for a spectacular destabilization of global climate. As this winter shows, in a shifting climate some places get colder and some warmer, some wetter and some drier. It’s also hard to know what is glitchy and what is part of a trend. This can be very stressful on the ground. But it doesn’t make for a global climate tipping point of the sort McPherson is so confident in.

