December 1, 2006

Are Humans Involved in Global Warming?

A recent issue of Environmental Geology contains an article entitled “On global forces of nature driving the Earth’s climate. Are humans involved?” by two scientists at the University of Southern California. Before we examine the article, let’s get a few things on the table. First of all, the two authors (Khilyuk and Chilingar) are faculty members at what most would agree is a world-class academic institution. If their work was not up to the standards of the University of Southern California, they wouldn’t be there for long. Second, Environmental Geology is an international multidisciplinary journal concerned with all aspects of interactions between humans, ecosystems, and the earth. It is published by Springer which is one of the leading academic publishing companies in the world. The editorial board of Environmental Geology includes 53 leading scientists from every corner of the planet; US institutions listed as primary affiliations of board members include the US Geological Survey, the University of New Orleans, the University of Missouri, the University of Kansas, the University of Oklahoma, Temple University, Wesleyan University, Oak Ridge National Laboratory, and so on.

The point is that Environmental Geology is a first-class journal, papers submitted to the journal are peer-reviewed by scientists at major institutions, and the journal is certainly not part of any industry-funded conspiracy to undermine actions on global warming. Submitting a paper to any journal in which you question whether humans are involved in global warming will assure a more stringent review than normal.

OK – what on earth is this paper all about? How in 2006 could credible scientists seriously question whether humans are involved in global warming? Recall that Khilyuk and Chilingar are writing for a professional journal in geology, not climatology, and it is only natural to expect geologists to look at trends in the context of very long periods of time. Their perspective on climate change would be quite naturally different from someone trained in looking at annual, decadal, or 100 year changes in climate.

The authors begin the article with the sentence “Identification and understanding of global forces of nature driving the Earth’s climate is crucial for developing adequate relationship between people and nature, and for developing and implementing a sound course of action aimed at survival and welfare of the human race.” Now who would argue with that statement? From there, they review the literature on solar output variations and earth’s temperature and show that a “one percent increase in current solar radiation reaching the Earth’s body translates directly into approximately 0.86 K increase in the Earth’s global temperature.” They show that the earth’s orbit about the sun changes over long periods of time resulting in up to a 7.5 K (1 K = 1°C = 1.8°F) modulation of the earth’s temperature. They describe how outgassing alters the composition of the atmosphere over long periods thereby altering the temperature of the earth over by over 50 K. They finally review microbial activities at the interface of the lithosphere and atmosphere that also substantially alter the composition and temperature of the global atmosphere at geological time frames. Initially, the article seems fairly tame, but as one reads more, the article becomes quite controversial.

Khilyuk and Chilingar repeatedly quantify the effect of the various processes that alter global temperature and conclude “The scope and extent of these processes are 4–5 orders of magnitude greater than the corresponding anthropogenic impacts on the Earth’s climate (such as heating and emission of the greenhouse gases).” This seems fair enough given the geological time scales considered by the authors, but you can see where the global warming crowd would be getting more uncomfortable.

The authors place the recent warming into an interesting perspective noting “the global warming observed during the latest 150 years is just a short episode in the geologic history. The current global warming is most likely a combined effect of increased solar and tectonic activities and cannot be attributed to the increased anthropogenic impact on the atmosphere. Humans may be responsible for less than 0.01°C (of approximately 0.56°C (1°F) total average atmospheric heating during the last century)”. Holy cow, can you imagine the letters and e-mails they must have received in response to that conclusion? They even show that over the last 3,000 years, the earth has cooled, or if you look just at the last 1,000 years, the earth has been cooling as well (the earth was in the Medieval Warm Period 1,000 years ago).

Their conclusions with respect to potential policy will more than raise some eyebrows as well as they write “Any attempts to mitigate undesirable climatic changes using restrictive regulations are condemned to failure, because the global natural forces are at least 4–5 orders of magnitude greater than available human controls.” They show that the climatic effects of the Kyoto Protocol would be negligible, leading them to state “Thus, the Kyoto Protocol is a good example of how to achieve the minimum results with the maximum efforts (and sacrifices). Impact of available human controls will be negligible in comparison with the global forces of nature. Thus, the attempts to alter the occurring global climatic changes (and drastic measures prescribed by the Kyoto Protocol) have to be abandoned as meaningless and harmful.”

Our World Climate Reports uncover and present interesting results we find in the peer-reviewed professional scientific journals, and as we have seen over and over, there are many absolutely amazing papers published regularly in outstanding journals. The global warming crusade would denounce this paper as outrageous, but it survived rigorous peer-review, the editor elected to publish it, and like it or not, this paper is part of the serious science literature. Dismissing the paper is made more difficult given the affiliation of the authors and the prestige of the journal.

The debate on climate change is never boring, the debate is full of surprises, and anyone claiming the debate is over is simply dismissing a significant number of papers that appear regularly in the major journals.

Reference:

Khilyuk, L.F., and G. V. Chilingar. 2006. On global forces of nature driving the Earth’s climate. Are humans involved? Environmental Geology, 50, 899–910.




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