2011-05-22 19:48:38Geologists and climate change denial
John Cook


I have to send this to ABC Environment tomorrow - they asked for a piece on geologists and skepticism. Feedback welcome:

Geologists and climate change denial

I was headed to the Sydney ABC studio to talk about climate change denial. What was unique about this interview was my coauthor Haydn Washington and I would have the opportunity to answer questions from callers. Considering the topic at hand, we expected some demanding questions from climate skeptics. On the way, I declared to Haydn I'd put money on someone bringing up past climate change. In every interview over the weeks following the launch of our book Climate Change Denial, the same question always arose: "Climate has changed naturally in the past so how do we know current climate change is caused by humans?"

Haydn wisely didn't accept the wager. And sure enough, the first caller introduced himself as a geologist and proceeded to discuss past climate change [ link to ABC interview ]. Afterwards, I reflected on geologists and the perception that they tend to be skeptical about human caused global warming. Australia's most well known skeptic, Ian Plimer, is a geologist and purports to speak for the rest of his field. But is the characterisation that geologists are mostly skeptics accurate?

One survey of earth scientists found that while 97% of actively publishing climate scientists agree humans are changing global temperatures, only 47% of economic geologists concur. In fact, among all earth scientists, economic geologists are the most skeptical. Similarly, in response to the consensus on global warming, the American Association of Petroleum Geologists "respects these scientific opinions but wants to add that the current climate warming projections could fall within well-documented natural variations in past climate and observed temperature data". You'd call that type of endorsement damning with faint praise.

However, the broader community of geologists seem convinced by the evidence that humans are causing global warming. The European Federation of Geologists "subscribes to the major findings that climate change is happening, is predominantly caused by anthropogenic emissions of CO2, and poses a significant threat to human civilization". The Geological Society of America concurs that "human activities (mainly greenhouse‐gas emissions) account for most of the warming since the middle 1900s".

So climate skepticism seems strongest among geologists closely linked to the mining and fossil fuel industries. Perhaps the words of Upton Sinclair shine some understanding on the forces at play here: "It's hard to get a man to understand something if his paycheck depends upon him not understanding it."

Regardless of motive, the question of past climate change is certainly an important one that provides much insight into how our climate behaves. Plimer's conceit is that as a geologist, he takes into account Earth's past while climate scientists ignore it. This is a curious position considering there is an entire field of climate science, paleoclimatology, that examines past climate change.

Climate has changed in the past. Sometimes it changes quite dramatically. Why? When something causes a change in global temperature, such as varying solar activity or changes in the Earth's orbit, feedbacks amplify these changes. The atmosphere grows more humid and with water vapour a greenhouse gas, this traps more heat. Arctic sea ice melts, causing the exposed ocean to absorb more heat. The feedbacks aren't so large that they lead to runaway warming but they are enough to amplify 1 degree of greenhouse warming to 3 degrees of total warming. Many different periods throughout Earth's history, from the last few millennium to millions of years ago, yield remarkably consistent results establishing this amount of climate feedback.

When geologists bring up past climate change, they're actually citing evidence for climate feedback. Dramatic swings in global temperature, dragging the planet in and out of ice ages, are possible because of these feedbacks. Renowned paleoclimatologist Wally Broecker sums it up beautifully: "The paleoclimate record shouts out to us that, far from being self-stabilizing, the Earth's climate system is an ornery beast which overreacts to even small nudges."

We have already given our climate a big nudge. How do we know it's us causing the warming and not natural causes? Because we've directly measured it. Satellites measure less heat escaping to space - direct empirical evidence that carbon pollution is trapping heat. Surface measurements measure more heat returning to Earth, confirming the increased greenhouse effect. We see many signatures of greenhouse warming such as winters warming faster than summers, cooling upper atmosphere with warming lower atmosphere and nights warming faster than days. The case for human caused warming is based on many, independent lines of evidence.

The feedbacks that amplified past climate change are now amplifying the warming caused by our carbon pollution. This is currently being observed. We're measuring more water vapor in the atmosphere, a strong feedback. Arctic sea ice is disappearing and satellites measure less sunlight reflected back to space - another significant feedback. The Earth's past and modern measurements all paint a consistent picture - our climate is already overreacting to our "nudge".

The peer-reviewed literature on past climate change sends a strong message, in stark contrast to what we hear from petroleum geologists. Past climate change is not a source of comfort. It's a cause for concern.

2011-05-22 20:13:04


1) "they tend to be skeptical about human caused global warming"

=> "they tend to be skeptical about human-caused global warming"


2) the following paragraph doesn't hang together:

However, the broader community of geologists seem convinced by the evidence that humans are causing global warming. The European Federation of Geologists [ http://www.eurogeologists.de/images/content/panels_of_experts/co2_geological_storage/CCS_position_paper.pdf ] "subscribes to the major finding...". The Geological Society of America concurs that "human activities (mainly greenhouse‐gas emissions) account for most of the warming since the middle 1900s". The Geological Society of Australia


- What is "the major finding"?

- What does the GS-Australia say?


3) "he takes into account Earth's past while climate scientists ignore it"

=> "he has taken into account Earth's past while climate scientists have ignored it"


4) "Satellites measure less heat escaping to space"

=> "Satellites measure reductions in heat escaping to space"


5) "on many, independent lines"

=> "on many independent lines"


6) "caused by our carbon pollution"

=> "caused by our carbon-dioxide addition "

I think we want to avoid the side issue of "is CO2 a pollutant or not?": Would be an unnecessary distraction here.


7) "It's a cause for concern."

=> "It's an indication that we need to be concerned."

2011-05-22 21:00:54
Rob Painting

I wonder if it's worthwhile briefly covering Svante Arrhenius?. You've covered that past change implies greater change in the future, but the whole "climate's changed before"thing, is also dredged up in order to paint a false historical narrative. The first thing scientists studying this issue did, was to look for natural causes!. Doh!. It isn't (as the skeptics like to claim) a matter of scientists developing tunnel-vision, focusing on CO2 and  excluding other lines of inquiry. No, the first thing they did was to look for natural explanations, which have now been weighed, measured, poked and prodded and found seriously wanting!                       

2011-05-22 23:15:45
James Wight


“the last few millennium” --> “the last few millennia”

The Geological Society of London have also released a statement on geological evidence about climate change. It makes a case against CO2 with no reference to climate models, weather stations, or even hockey sticks.

2011-05-23 04:45:07
Dana Nuccitelli

Good article, and good suggestions so far.  I was going to mention the British Geological Society, but couldn't remember the exact name.  Glad James knew it.

I'd also suggest when you say 1 degree from GHG leads to 3 degrees total, linking to climate sensitivity is low.

2011-06-07 05:59:00
Andy S


I'm a member of the AAPG (American Association of Petroleum Geologists). You should be aware that their current lukewarm policy is actually a major victory for the minority of members (including me) who spoke out and threatened to quit if they didn't move from their previous position which was truly denialist. (They tried to make up a fact sheet on climate change that didn't, even once, mention carbon dioxide, for example.) I think the AAPG got spooked by realizing that they could lose many of their academic members, their international members (European oil geologists are far less prone to be deniers) and younger members.

The Canadian equivalent society (CSPG) is even worse than the AAPG and I'll not rejoin the CSPG until such time as  the Arctic refreezes over.

I think that there is another factor, the idea of gradualism and consequent resistance to the now largely defunct ideas of catastrophism, which is drummed into the heads of every undergraduate geologist, that explains part of the resitance of (some) academic and (many) industry geologists to the idea of a sudden change in the climate. Of course, the Upton Sinclair quote applies to many in the extractive industries.

I'll post some extended comments when the article is published.

2011-06-07 07:25:35


"... far from being self-stabilizing, the Earth's climate system is an ornery beast which overreacts to even small nudges."


Edward Norton Lorenz would have endorsed that statement.  It was he who coined the term 'butterfly effect' in connection with his studies of atmospheric perturbation.  See e.g.

Lorenz, Edward N., 1969: Atmospheric Predictability as Revealed by Naturally Occurring Analogues. J. Atmos. Sci., 26, 636–646.  Free pdf available:



The climate is always changing.  Everything is always changing.  You can never step in the same stream twice because the water is constantly changing.  In the same vein, neither you nor nature can ever do exactly the same thing twice: everything changes with age.  Saying that the climate has always changed is like saying that snow melts: it adds nothing whatsoever to the sum of scientific knowledge.  It serves only to distract public attention from the real issue: climate has always changed - but mostly not so fast as now.

2011-06-08 15:04:57Article just got published on ABC Environment
John Cook



2011-06-08 17:25:21
Andy S

Read it and weep http://opinion.financialpost.com/2011/06/07/climate-isnt-up-for-debate/
2011-06-08 17:30:06
Andy S

Andrew Miall has a pretty good reputation as a geologist. Norm Kalmanovitch is a deluded nutcase, on the other hand. Plimer and Carter we all know. Sent from my iPad, so I am limited with formatting, sorry.
2011-06-08 19:45:01


The author of the piece is known to be a PR hack.

A better question: Does anybody know anything about GAC-MAC 2011 (the Joint Annual Meeting of the Geological Association of Canada, the Mineralogical Association of Canada, the Society of Economic Geologists and the Society for Geology Applied to Mineral Deposits)?

It would seem as though GAC would be some kind of superset of the following, so maybe this is like a chapter meeting of GAC? Or was it a full GAC meeting? Certainly the other groups seem to have little scientifically to do with climate change.

In any event, I don't fault the real climate scientists for abstaining: Debate is debate, and it is unsuitable as a means of settling scientific differences.

2011-06-09 01:17:44Dumb question???
John Hartz
John Hartz

What the heck is an "economic geologist"? 

2011-06-09 01:21:43
Dana Nuccitelli

My understanding of an 'economic geologist' is basically one who works for the private sector.  Many are petroleum or mining geologists, hence their high percentage of 'skepticism'.

2011-06-09 01:35:12


Here's the Plenary Address abstract for the GAC-MAC. Their basic background is rock-stuff: mining and mineralogy.


Plenary Address (40 min):  Humanity's greatest risk is risk avoidance

Cathles, L.M., Cornell University, Ithaca, NY 14853, lmc19@cornell.edu

As economic geologists, our challenge is to provide the ultimate world population of 10.5 billion with the energy and materials needed to sustain a European standard of living indefinitely.  Any other goal has almost unthinkably negative implications.  Can we do it?  Of course!  Considering the oceans, the world is a planet awash in energy with ample material resources.  Raising energy consumption to the current European level of 7 kW/p would require tripling total energy production (15 TW to 45 TW).  Accommodating 1.5 billion 100 years from now will require 72 TWe.  Growing from 15 to 72 TW over 100 years represents a modest compound growth rate of 1.6%/yr.  With breeder technology, the 4.6×109 tonnes of U dissolved in the oceans (not to mention Th which is a better nuclear fuel) can sustain a 72 TW production for 78 centuries.  My estimated seafloor Cu and Zn resources can sustain humanity for 50 and 140 centuries, respectively.  Less than 3% of the Li in the oceans would allow 10.5 billion to share ¼ of a hybrid car.  The deep oceans contain enough phosphate for 33 centuries of agricultural production.  So if we tap the oceans, humanity will have the resources needed for a sustainable future.  There is of course some risk, but humans are tremendously good at solving problems once they have been identified, and this means to me that we will be able to recover resources from the oceans with minimal and ever-diminishing risk, as we are currently doing.  The greatest risk seems to be the timidity bred of specialization (no one being sure what someone else is doing).  Rather than fearing what our neighbor is doing, we should have confidence that our neighbors can fix whatever goes wrong.  We should engage the next generations by moving forward with a positive, world-inclusive agenda and impressing them, not with the immensity of future pain, but by the immensity of future gain (everyone indefinitely at a European standard and huge opportunities to increase scientific understanding of how natural, including resource, systems work).  If we do this, the future of our profession and humanity will be very bright indeed.

2011-06-09 01:42:58


James Wight: The statement by the GSL is currently quite different from what you describe. Here's the last few lines:

"In the coming centuries, continued emissions of carbon from burning oil, gas and coal at close to or higher than today’s levels, and from related human activities, could increase the total to close to the amounts added during the 55 million year warming event – some 1500 to 2000 billion tonnes. Further contributions from ‘natural’ sources (wetlands, tundra, methane hydrates, etc.) may come as the Earth warms22. The geological evidence from the 55 million year event and from earlier warming episodes suggests that such an addition is likely to raise average global temperatures by at least 5-6ºC, and possibly more, and that recovery of the Earth’s climate in the absence of any mitigation measures could take 100,000 years or more. Numerical models of the climate system support such an interpretation44. In the light of the evidence presented here it is reasonable to conclude that emitting further large amounts of CO2 into the atmosphere over time is likely to be unwise, uncomfortable though that fact may be."

2011-06-09 10:05:51
Andy S


"Economic Geology" usually means geologists who work in mineral exploitation as opposed to those who work in oil and gas. But there are exceptions, for example,  the Bureau of Economic Geology in Austin, Texas is a university department mostly working in energy and environmental  research.

Not all economic geologists are employed in the private sector. University earth science departments often have substantial numbers assigned to subjects directly or indirectly linked to minerals or hydrocarbons. National and state geological surveys are partly or mostly staffed by geoscientists working on some kind of resource assessment and mapping project.

The GAC MAC meeting is predominantly hard-rock oriented, meaning minerals rather than hydrocarbons. As I said earlier, Andrew Miall is quite a distinguished geologist (he's a sedimentologist) but he seems to have "gone emeritus" like Happer and Dyson with rubbish like this on climate change.

2011-06-09 12:13:17



I believe you are being a bit unfair to Miall: Listen to this, and I think you will agree he has not "gone emeritus."

The summary you linked is too brief to express what he is trying to say; but in brief, he is mostly just being careful about exactly what conclusions are being drawn; although he points out a few places where the picture is being oversiimplied, he is more than concerned about AGW.

I don't know his reputation, since I'm not a geologist; but he sounds like a careful and insightful scientist to me. I would push back a bit on the polar bear situation (it's happening very fast for them); and I would point out that Gore was already deliberately vague about the cause/effect situation with respect to CO2 and temperature increase. But his main point is that we shouldn't over-simplify.

2011-06-09 13:09:38
Andy S


Neal: Thanks for that! I retract my "emeritus" snark. And I agree with your assessment.

I do, however, feel that he constructed his abstract quite deliberately to sound provocative. (CO2 lags temeprature, climate's changed before, glacier retreat isn't relevant. polar bears), Sometimes serious scientists get so ticked off about people they basically agree with for over-simplfying or exaggerating the case that it's hard to tell whose side they are on. (I did the same once after seeing the Inconvenient Truth movie; there were a number of things I didn't like about it and I went on about it so much that a friend to this day is convinced I'm a climate denier.) Lord knows, when I am writing stuff for publication here I find it really hard to simplify and I fear that I am going to be called out by someone like Miall for exaggeration.

Yes, Mialls views are nuanced and well-informed but in some ways, I think he's pandering (or at being least overly tolerant) to certain skeptics while being tough on Gore and co. Perhaps I should have likened him more to Judith Curry than Dyson.

2011-06-09 14:37:28
James Wight


Neal: Okay, so there's almost no reference to climate models.

2011-06-09 17:09:46



No, Curry is a spineless hypocrite.