This is a long review of the new book "The Chilling Stars" and warrants its own post.
The Best Popular Introduction to Climate Science, April 25, 2007
Fritz R. Ward "dayhiker" (Crestline, CA United States) - See all my reviews For many years it has been known that periods of global cooling are associated with with reduced solar activity. In the 1970s, Jack Eddy of the High Altitude Observatory in Colorado named the correlation between the lack of sunspots and the consequent decline in earth's temperature the "Maunder Minimum" and showed that similar sequences of global warming and cooling were also associated with increasing and decreasing solar activity. Until recently, however, no one has been able to provide a mechanism explaining why this correlation exists.
Henrik Svensmark, however, has done just that in his published work and with the help of science writer Nigel Calder has provided a very readable explanation of how solar activity affects climate change. This book has profound implications for policy debates in this country and deserves a wide audience. Svensmark's theory is that cosmic rays which originate from collapsing stars (novas) are the primary cause of cloud formation, in particular the formation of low level clouds, those 3,000 meters above the ground and lower. Muons, basically very dense electrons, which are among the few cosmic particles to survive the solar winds and contact with the earth's atmosphere to sufficiently interact with with atoms near the surface, liberate electrons in the atmosphere which in turn join with molecules that form stable clusters. These clusters attract a small amount of sulphuric acid and then water molecules to ultimately generate water droplets, the basis of cloud cover. But how exactly does cloud cover affect climate?
Most climate models simply see clouds as a byproduct of climate changes, but as Svensmark and Calder demonstrate, clouds themselves are the predominant factor in global cooling. Although they trap heat between the clouds and earth's surface, they also reflect radiant energy from the sun back into space. The net effect of low lying clouds is therefore a cooling one. And, as it happens, all periods of global cooling have coincided with increasing cosmic rays and cloud cover.
The implications of this theory are quite startling. For one thing, it almost completely eliminates increases and decreases of carbon dioxide and other so called green house gasses (GHG) from the equation of climate change, a matter of some concern to those who use fears of anthropomorphic global warming to advance their political agendas.
Indeed, when Svensmark first proposed his theory in the mid 1990s, it was called "dangerous" because, if correct, it would undermine the vast public funding currently available to the many scientists who feed off of global warming fears. Unfortunately for them, Svensmark's theories have since been experimentally vindicated, something that cannot be said for the "models" that GHG advocates use to prop up their increasingly discredited arguments.
Indeed, Svensmark's "chilling stars" are able to explain all the data that other climate change models note. For example, since 1900 the solar magnetic field has almost doubled, resulting in a dramatic decline in the amount of cosmic rays reaching the earth's surface. There has been a consequent temperature increase (.6 degrees Celsius) and an 8.6% decrease in cloud cover. This results in "a warming of 1.4 watts per square meter."(p. 80) But this figure is crucially important because it is precisely the same figure that advocates of the man made global warming hypothesis say is the result of increases in greenhouse gases.
What this means is that natural variation almost entirely explains all observed temperature increases this century, and this model, unlike the GHG model, is experimentally vindicated. But what really sets Svensmark and his colleagues apart from the man made global warming advocates is that this model, while also explaining the observed rise in temperature, also explains the data that the other models ignore, and in some cases irresponsibly cover up.
For example, it is well known that Antarctica is not experiencing global warming. This is part of a long term climate trend in which Antarctica has for thousands of years experienced cooling while the rest of the world warms, and warming as the rest of the world cools. It is part of the troubling evidence that skeptics of man made global warming routinely bring to the table and which popular films like Al Gore's "An Inconvenient Truth" conveniently ignore.
Advocates of GHG as the primary mover of climate change typically try to brush off this anomaly by explaining that they need "more data." But Svensmark explains it easily. The Antarctic ice cap is the one place on earth that is so reflective that it actually loses more radiant energy on cloudless days than on cloudy ones. So, while cloud cover cools the rest of the planet, it warms Antarctica, and as the rest of the planet warms with a decrease in cloud cover, Antarctica cools.
Similarly, Svensmark's work explains the cooling trend the world experienced from the 1940s to the mid 1970s. This period also saw one of the greatest outputs of GHG in history and man made global warming theorists have a great deal of trouble dismissing it. Indeed, for a long time they ignored it but following the publication of Michael Crichton's novel 'State of Fear' this anomaly became common knowledge among the literate public.
This period also coincides with a slight reduction in solar activity and a slight increase in cosmic ray induced cooling. In terms of the history of global climate, this cooling was not very dramatic, but it was sufficient by 1975 to lead many popular publications to speculate on the coming of a new ice age. Interestingly enough, the solution to "global cooling" political activists sought in the 1970s also involved a reduction in fossil fuel usage, so one might reasonably be skeptical now of their claims to solve global warming by the same technique.
The value of Svensmark and Calder's book, however, extends far beyond the current debates on global climate change and what, if anything, we as a society should do about it. They note that periods of warming and cooling have had a tremendous impact on human history, including the development of agriculture, and on the whole development of life on earth. Indeed, their research suggests ways to narrow the search for life in other parts of our galaxy.
The final chapter of the book describes the myriad of research projects that will open up to investigators once this new (but already well tested) paradigm of climate change is adopted. But the promise of new research, even the promise of a better model, is hardly sufficient to insure the adoption of Svensmark's "Chilling Stars" as a new paradigm for research in the modern era.
Historically, as Thomas Kuhn has demonstrated, "science" advances by using a paradigm, a carefully constructed set of theories. These paradigms guide research until a point at which there are too many unexplainable gaps in the theory for the paradigm to continue to be useful. At this point, a new paradigm replaces it. Usually the process by which one paradigm replaces another is fraught with argument, debate, and in some cases dramatic confrontations among advocates of competing ideas. This is how science operates and it generally works quite well.
Svensmark's work has been subjected to just this sort of rigorous testing for the last decade and has shown itself to be remarkably versatile. However, late 20th and 21st century science is altogether different than science in earlier periods of human history. Scientists used to be motivated by religious considerations (a desire to better understand creation) or humanitarian motives (curing diseases like polio) or simply curiosity. Such motivations are still common among many scientists.
But increasingly, political advocacy coupled with the public funding of science has led to a new motivation for science: the advancement of a political agenda. In such an environment, it may not matter that the work of Svensmark and his colleagues better explains climate, the development of life on the planet, and even better predicts the future. The political usefulness of their studies does not, at present anyway, coincide with that of the UN's Intergovernmental Panel on Climate Change (IPCC) and so it is quite possible that their work simply will not get the attention it deserves.
This signals a dramatic, and perhaps fundamental, change in the way science operates. Will the future see a continued commitment to experimental research and the free publication of diverse views, or will the modern scientists win out, stifling open debate and corrupting data to advance their agendas.
The case of Michael Mann and his famous "hockey stick" graph is instructive in this regard. Mann, an advocate of the man made global warming hypothesis, knew that the medieval warming period and the little ice age of the last millenia contradicted the GHG theory. So he simply revised history by creating a chart that that showed a stable climate for a thousand years followed by a dramatic increase in the 20th century. He also hid his raw data and algorithms from public and scientific scrutiny for almost a decade, an act that would have immediately disqualified his work from serious consideration among the previous generation of scientists. But in the "Brave New World" of science, his graph graced numerous IPCC publications. Calder rightly calls Mann's work "Orwellian" and dismisses it in favor of finding a theory that accurately explains, rather than explains away, actual climate changes in earth's history. But one cannot help but wonder if Orwell's vision was correct. Time, and in particular, the reception of this spectacular book, will tell. Be sure to get the book yourself and enjoy the read.