The final talk of the meeting was by Jan Zalasiewicz titled ‘Looking back from the future at the Anthropocene’. It is clear from this talk that some geologists have already decided humans are having a dramatic effect on the earth, which reinforces efforts to give the current geological period of the earth a separate classification, the Anthropogene. I find this kind of science disturbingly self-serving. A few days after the talk after I wrote Dr. Zalasiewicz the following letter:
Dear Dr. Zalasiewicz,
I recently attended the Life and the Planet meeting in London (May 5-6, 2011) where I heard your talk “Looking back from the future at the Anthropocene”. You presented a fair amount of information suggesting that humans are presently having a rather severe impact on the earth system, all in support of your thesis that human activities will define the Anthropocene. I was stuck by the last sentence of your abstract, which states: “The effects of warming and acidification are in their early stages; as these intensify, consideration of the Anthropocene as merely an epoch may come to be seen as conservative.”
I wasn’t aware that the science around future projections of climate and ocean changes was as settled as you seem to suggest. I say this not to challenge your personal beliefs, but to point out that there are many qualified scientists like myself (a former staff scientist at the National Center for Atmospheric Research) who do not believe the climate models are anywhere near reliable enough, and the complexity of the earth system well enough understood, to make such unqualified projections of climate on a geological time scale. You may well be right, but you might find your message would be better received by critical scientists by pointing out the uncertainties in your projections.
I was particularly disappointed to see your slide depicting global surface temperatures over the past 1000 years, taken from the 2001 IPCC Third Assessment Report, aka the hockey stick graph.
Might I ask, are you aware of the controversy around the hockey stick (see http://en.wikipedia.org/wiki/Hockey_stick_controversy)? I realize that as a geologist you might not be up to date with the current climate debate. If so, then let me tell you that the hockey stick graph has been shown to contain serious problems in the choice of proxy data and statistical methods. Several peer-reviewed scientific papers have been published that discuss these problems, including a recent statistical analysis (McShane and Wyner 2010 – Annals of Applied Statistics) showing significant errors in the hockey stick analysis. An excellent detailed account of the controversy can be found in “The Hockey Stick Illusion” by Andrew Montford. I am happy to provide you with detailed references if you like, though most of the references can be found in the link provided above.
The Anthropocene may well come to pass, but I doubt it will hinge on global warming. I encourage you to investigate some of the uncertainties that exist in our understanding of the earth’s climate. If you do, you may find that many claims of anthropogenic global warming do not hold up under careful scrutiny.
Lee Klinger, PhD
Dr. Zalasiewicz responded promptly (with permission to post his reply):
Thanks for your comments. I’m sorry if in the abbreviated form of the abstract I gave the impression that climate science was now ‘settled’. It isn’t, of course. Nevertheless, there seems to be a reasonable consensus (among my working colleagues as well as, as far as I can judge, more widely within the earth and climate sciences) that something like the IPCC view – hedged around as it is with words such as ‘likely’ and ‘probably’ – is a reasonable interim analysis, before the reality of the future overtakes us. That would probably include Michael Mann’s graph, though in talks I normally do mention the controversy surrounding that. I’m aware of Andrew Montford’s arguments, of course.
As a geologist with some experience of climate in Earth history, I would be surprised (and relieved – or rather my descendents will be relieved!) if the Earth remained inert to the changes in radiation balance, albedo etc caused by human activity. One must only hope that the critics of the IPCC have a point
with good wishes
He adds in a follow up email:
For the record, I’m a card-carrying sceptic about everything (field geologist roots, you see) who is nevertheless impressed (and worried) by the combination of stratigraphic and contemporary evidence that suggests that the world’s climate will change (likely warm) significantly, if not smoothly (there seem to be many hiccups in Earth history) over the coming centuries and that the role of anthropogenic CO2 in this will be significant. The Anthropocene concept, of course, is based on a wider array of phenomena of which part (widespread changes to surface sedimentation and habitats; biotic transformation through worldwide species invasions etc) has already happened. Its relative scale vis-a-vis past perturbations is work in progress, though so far it doesn’t appear trivial.
I appreciate Dr. Zalasiewicz’s candidness, though I am disappointed with his defense of the Hockey Stick graph in his talk. This seems to be another example of a global warming alarmist using whatever science is at hand to support his beliefs, even if that science has been shown to be flawed. The use of this controversial graph did not go unnoticed among my colleagues, and while they chose not to question its use, I refuse to stand by and allow the Hockey Stick graph to be presented at a major scientific meeting without mention of its errors.