“Nothing is more dangerous than having just one idea” - Emile-Auguste Chartier (1868-1951)

I came across an article I read today about the Arctic region being tropical 55 million years ago. It briefly mentions climate change, which has been a topic I've been interested in for quite a while. Until recently, I wouldn't have raised an eyebrow when put forth with the following statement: the climate is getting warmer because of human-induced pollution. I think that most of the public would agree with it. I don't. There are several factors that forced me to reconsider my view.

We are so tiny

I've always been amazed at the short-history of Homo sapiens (~200,000 years) when compared to the longevity of DNA: perhaps as long as 4 billion years ago. If we assume those numbers are correct, we've only been around for 0.005% of the history of life on Earth. That's a very short time indeed. During that time, the climate of the Earth has gone through many changes. For example, as mentioned earlier, the Arctic region was tropical 55 million years ago. Similarily, the Earth has experienced a warming trend for the last 10,000 years. The point is that if we look at very long periods of time, the Earth's temperature has warmed and cooled repeatedly--trends that have nothing to do with human activities (we didn't exist yet!).

Non-anthropogenic factors

The trends described above take place outside of the zone of potential human-borne climate changes (if climate changes are anthropogenic, they could only have started ~10,000 with the advent of agriculture and non-nomadic life). What are the non-human factors that contribute to changes in temperature? I remember reading a very good book about the history of human civilization by Jared Diamond called Collapse: Why Societies Choose to Fail or Succeed. The thesis of the book is that five main factors determine whether a society will succeed or fail. They are:

• Human-inflicted damage to the environment, the extent of which depends on consumption of resources and the resiliency of the environment
• Natural climate change caused by the amount of heat put out by the sun, volcanic eruptions, changes in the orientation of the Earth's axis with respect to its orbit, and changes in the distribution of land and ocean over the face of the Earth, among other factors.
• The extent of hostile neighbors
• The extent of friendly trade neighbors
• A society's responses to its environmental problems

(See the full review on genesistheory.com)

While the first factor might hint at today's problems, the second is more interesting, because Jared Diamond never discusses human-induced climate change on a global scale. That by itself doesn't mean that Dr. Diamond doesn't think global warming is anthropogenic, but I found it interesting that it wasn't mentioned in his book.

What really made me doubt human-induced global warming was reading Michael Crichton's State of Fear. The book is a fiction about a group of left-wing environmentalists who want to change public perception and policy about global warming by committing terrorist acts. They believe that without creating catastrophies, the public will never pay enough attention to the topic.

The plot is average while character development is extremely shallow. Neveretheless the book is worth reading because the two points of the books comes across loud and clear: a) there is plenty of data to suggest that global warming is not due to human activities and b) mixing undocumented science with policy is very dangerous. Regarding the first point, Crichton backs up every arguement with cited scientific data. For example, he points to data that shows that human-generated CO2 makes up an extremely small volume of the total atmosphere (see these contrarian views and other factors driving climate change on Wikipedia; greenhouse-effect data).

"Consensus Science"

On the latter point, two of his speeches are included in the book in which he details what he believes are popular but false assumptions based on "consensus science" that can have an impact on public policy: nuclear winter, second-hand smoke, DDT, and social darwinism. He also makes a point of comparing the beliefs of some atheist environmentalists with those of Judeo-Christianity, which is very interesting indeed.

Crichton's argument can be extended to many other aspects of human life in the past and present. It's in human nature to try to make sense of the unknown. Remember the Catholic Church persecuting Science?; the Salem Witch Trials?; the German-Nazi ideology of the 1920s and 1930s?

The point is that we shouldn't assume that widely-held but unsubstantiated ideas are true, especially because human beings are susceptible to instinctive judgements and conformity (i.e., brainwashing; more to come on that topic in a future entry). It is entirely possible, and most would say probable (see this excellent PBS Nova series "Dimming the Sun"), that global warming is human-induced--but we really don't know, and thus should be careful to make public-policy decisions based on assumptions.