Ecologist Guy McPherson has been touring New Zealand for the past couple of weeks, explaining why humanity has only 10 years to live (a kind-of Ziggy message that has immediate appeal to me). After his appearance on the Paul Henry breakfast show, I was called by TV3/Newshub for comment. Based on my understanding of climate change science I said that though the situation is very serious — dire even — extinction in 10 years is not going to happen. When I gave my remarks to Newshub, I knew little about McPherson but I understood that he is a very knowledgeable biologist who should not be dismissed lightly.
So, what’s the story? Is McPherson right? Is the IPCC woefully conservative and keeping the truth from us all? I had the opportunity to hear Prof McPherson speak in Paraparaumu on Saturday (Dec 10th) to get more insight into what his views really are. It was a very interesting presentation, and a very interesting discussion with the audience of 50-odd Kāpiti coasters who showed up to hear him. As the old saying goes, extraordinary claims require extraordinary evidence. What we heard was extraordinary for sure, but was not too convincing in terms of evidence.
McPherson’s presentation was as much philosophy as science. Much of his message is built around the undeniable truth that we are all, one day, going to die. Hence, we would do well to live in and for the present, express our love to those close to us, and act rightly according to our own beliefs and principles. Excellent advice, and a great philosophy for living well, what you would be told in any number of “life-coaching” books. Where he differs from most is in saying that all of us, i.e. all of humanity, and most other species, will be extinct in 10 years or so. Why is that, you might ask?
The detail on his view of the climate system can be gained by reading his “monster climate change essay”. A briefer overview, and what he bases much of the scientific side of his presentation on, comes from a blog postat the Arctic-News blogspot site, written by “Sam Carana” (not his or her real name – you know why). This piece suggests that the globe will warm around 10°C in the next decade, and since such warming was associated with mass extinctions in past epochs, humanity and most vertebrates etc will be toast very soon.
The blog post starts by assuming the February 2016 global mean temperature represents the current average temperature of the earth, then throws in another 0.8°C for pre-1900 (0.3°C) and unavoidable future (0.5°C) warming. This is pushing it, as February was the warmest single month on record (in difference from normal terms), several tenths of a degree above the annual mean for 2016, and the amount of unavoidable future warming is small (maybe 0.1°C?), should greenhouse gas emissions stop now.
However, the next steps are where McPherson’s grasp of the science seems shakiest. Cutting aerosol pollution to zero (as would happen when and if industrial society falls over) will unmask another 2.5°C of warming. This is a factor of ten too large, as the actual amount would be around 0.25°C by current best estimates (see figure 10.5). Reduced planetary reflectivity (albedo) from loss of Arctic ice will add another 1.6°C (perhaps in the Arctic, but not in the global mean), plus the water vapour feedback, seafloor methane release etc will add an extra 3.5°C. So that’s another 7.5°C on top of essentially where we are at now, giving a total of about 10°C warming compared to pre-industrial, assumed to happen in the next 10 years. Then, all the world’s nuclear reactors melt down, and we are all extinct.
The way Guy McPherson talks about water vapour shows his sketchy grasp of atmospheric physics. He states that most of the water vapour in the atmosphere is above 6km altitude, where it “acts like a lens” to heat the earth. Most of the water vapour is actually in the lowest few kilometres of the atmosphere, as the upper troposphere is too cold to support much water vapour. Perhaps he’s thinking of the release of latent heat in the tropics, which does occur mostly in the upper troposphere, leading to a warming “hot spot” in the tropical upper troposphere as greenhouse gas concentrations rise (See AR5 WG1, figure 12.12).
Water vapour is of course a critically important part of the climate change story and is the main amplifying feedback of greenhouse gas increase. McPherson is trained as an ecologist, so it’s no surprise that he isn’t totally on top of the vertical profile of water vapour in the atmosphere. But, if your public profile depends on your image as an authority on “global warming”, you would do well to be clear on the science.
Now, the potential consequences of climate change, and the lurking feedbacks such as Arctic methane release and other carbon cycle changes, are an extremely serious concern, one that I think the governments of the world have yet to really take on board. The risks of severe food and water shortages, population displacements and conflict over resources, already has the potential to endanger hundreds of millions of lives – even with another degree or two of warming (as outlined in the last IPCC report). But truly catastrophic and extremely rapid climate changes do not look to be on the cards, at all. Earth’s climate is not poised for “runaway” change (as per Venus), nor is there any clear indication from the geological record that the climate system is so sensitive to greenhouse gas increase that 10°C of warming in 10 years is imminent, or even possible. The climate community of course does not know everything about past climate change nor about what the climate system is capable of if pushed hard. But, the extinction in 10 years scenario is really at the outer edge of speculation about the future.
Even without imminent extinction, the consequences of climate change are more than dire enough to galvanise us into action. My perception is that concerted global action within the next decade can avoid the worst consequences. The flip side is that business as usual, even for another ten years, could lock in changes that do indeed put global society at risk and threaten possibly hundreds of millions to billions of lives. Not instant death but a very unpleasant future for a very long time. I find that prospect plenty scary enough, and it leaves room for us to take action. Let’s take it.
Gareth adds: McPherson’s views are a good example of real climate “alarmism”. Deniers love to paint the IPCC or consensus position on climate change as alarmist, thereby implying that their rejection of that consensus is somehow sensible or moderate. McPherson’s stance shows that to be a mere debating trick. The truth, of course, is that by rejecting the consensus view on what we can expect, deniers are as extreme as McPherson — polar opposites, but just as guilty of exaggeration.
A couple of articles from scientists refuting McPherson’s work (in 2014), from a comment in the Hot Topic post,
Thanks for posting this weka.
As you are aware – my thoughts on the matter of MacPherson’s claims fall much in line with those of Jim Renwick and Gareth Renowden above.
Further to the above article on the misconceptions of MacPherson it is important to state that he bases his outlandish claims on a misunderstanding of feedback loops. His “thesis” is based upon the misconception that feedbacks are multiplicative, and true there are many differnt feedbacks in the climate system – both positive and negative, but he claims that they have a multiplying effect on each other which is clearly erroneous, as their effect are not multiplicative but additive – and that is a big difference.
Feedback loops have an exponential nature:
The feedback maybe exponential as you say – but that is not argument that MacPherson is making. There are numerous feedbacks (Water vapour, artic methane, albelio etc) – and his thesis is based upon a belief that they interact multiplicatively whereas they do not.
Does that mean that if take phenomena 1 and phenomena 2, they will each have the same effects together that they would alone, whereas GM is arguing that you get double (or whatever) the effect of each because they are happening together?
Yes essentially that is the case. By doing this he calculates a 10 degree increase in global surface temperatures in 10 years. That is obviously an outlandlish claim. And as Jim Renwick notes in his post on Hot Topic; inflates each forcing in some cases by a factor of 10 – eg the elimination of aerosols. He gets these figures by incorrectly misinterpreting the nature of feedbacks. He is an ecologist – not a physicist. However even ecologists need to understand the physics.
It’s entirely possible that they will interact multiplicatively rather additively.
It’s a complex system of relationships. An increase in one could result in a multiplicative increase in another.
Personally, I’d expect it to be a proportional change and that is always multiplicative although most like measured in decimals of less than one. Added together they then, overall, be greater than one and at that point we have an exponential increase.
No, I don’t think that things are as bad as McPherson thinks but I also don’t think things are as optimistic as the IPCC reports either.
Given that CC itself is exponential in nature, even additive feedbacks are a huge problem.
Climatologists use the term to describe different phenomena than the one described by sound engineers. Even jargon depends on context.
There was a post or comment about this on Realclimate some years ago – I’ll try and find a link…. to no avail. In any event, the terms are not interchangable:
Climate change feedback (Wikipedia).
I don’t really care about McPherson. As someone said in a thread hereabouts, he’s the carbon copy negative of a denier.
And as you know, I kind of do care about the numbers (eg – the available carbon budget and what not) . But anyway, putting all of that aside, something worth throwing in is that there seem to be a large number of people who don’t act because they believe we (or they) will be able to adapt as stuff ‘comes down the line’.
And that’s the scary one for me; this idea of, or faith in simple adaptation.
Even if we are of a mind to find it acceptable for those in temperate regions (us) to adapt to an average global surface temp increase of (say) 2 degrees even as that average surface temp increase makes living impossible for however many millions in equatorial or tropical regions, by the time we act on the basis of that immediate and impacting 2 degrees scenario, there will be another x degrees of warming locked in. And sure, maybe we adapt to that additional temperature too. But by then there’s another x degrees of warming locked in.
And this is putting any feedback loops to one side. But there seems to be a kind of Peter Principle implicit to the idea of adaptation because of the lag time in warming.
So whereas in management terms, the Peter Principle suggests that employees only stop being promoted once they can no longer perform effectively, and “managers rise to the level of their incompetence.” – relying on adaptation to survive likely CC we (or some lucky few in the right place) adapt right up until the situation we find ourselves in is beyond adaptation.
+1 Bill. Exactly my fears.
McPherson is a gift to the CC deniers. He gives their accusations of alarmism some credibility.
And that in a nutshell is the problem.
Canadian Climate Scientist, Paul Beckwith says we’re in a climate emergency.He believes we must:
1. Stop all emissions now
2. Geoengineer the Arctic to stop its melting
3.Start direct CO2 removal from the atmosphere asap.
Peter Wadhams also advocates we must do 2 and 3
Can’t see it happening though, we certainly will continue on our merry way with BAU and eventually CO2 will get to 450ppm.
Peter Wadham’s prognosis is dire.
Just because we don’t like the message we shouldn’t ignore it.
Yeah, I wouldn’t do the geo-engineering thing. The potential for disaster from it is very, very high (This Changes Everything, Naomi Klein).
Something I find really disappointing is when discussion starts about a specific mitigation measure such as a carbon tax, there are always poo-poohers jumping in to say we shouldn’t be dreaming about it because it’s not enough on it’s own to solve the problem.
There is no magic bullet, there’s just the sum of a lot of different mitigation measures we can do now, a lot of development of new mitigation measures, and a lot of adaptation we won’t be able to avoid. How much and how expensive the third one will be depends on how serious we get about the first two.
Too many people put far too much store by carbon pricing. And the studies show, conclusively, that a price on carbon as a central plank to any mitigation policy…well, it’s akin to standing on a train track and walking down the tracks ‘away’ from the train. Doesn’t even really buy much time.
Walk, cycle or use public transport
Reduce meat, fish and dairy consumption (or stop eating them)
Grow vegetables and fruit trees
Turn off the lights, get rid of TV, dishwasher, dryer, heat pump, motor mower, leaf blower, hedge and string trimmers
Reduce or stop air travel overseas
When travelling stay in a homestay, camping ground or apartment
Go boating in a sailboat
Avoid packaged goods
Get a big, well made kete and use it
and hope like fuck science comes up with a fix because 7 billion humans and climbing says that we art going to learn the hard way what happens when you ignore cause and effect.
Some interesting thoughts If Tillerson (ExxonMobil CEO) gets the nod for Secretary of State it will open up opportunities to publicize how they’ve been deceitful about climate change since the 70s at least
When are we going to face up to the population issue?
It’s time we made having children considerably more expensive. We do not need more humans. This is going to be a very hard call but someone needs to make it.
Turning off appliances is not going to cut it.
if nothing else McPherson at least got climate change on the news and on the home pages of the daily newspapers for a few days……no mean feat in the current environment.
A different perspective on climate (change) and possibly off-topic, but only ever so slightly IMHO, and a very interesting read:
did any of you even see how fast the last tens went bye?
i just came across this at the site of the great orange satan aka Dkos.
A diary about winter in Iceland that apparently never came this year.
but other then that all is well.
Jim Renwick states ” My perception is that concerted global action within the next decade can avoid the worst consequences.” But are those with power to take ” concerted global action” coming anywhere close to this? The Paris agreement can hardly be decsribed as “concerted global action”. Thats the worry. For those with the power, retaining that political power and the focus on economic “growth” are the antithesis of what is needed.
Renwick’s science is at least 10’years out-of-date and hopekessly inaccurate. You don’t have to accept the near-term extinction but you can’t fault his science . Every statement is supported by scientific research that is at least up-to-date.
How about doing something radical and start with reality and then sort out your response.
Here is Prof. McPhersons response to Renwick
Right at the end of Guy McPherson’s NZ tour Prof. James Renwick of Victoria University turned up and introduced himself. Instead of checking out the up-to-date references provided to him Renwick wrote a hit piece relying on grossly out-of-date information from the 4th IPCC Report.