Product Description

Scientists agree that over the last century the earth has become warmer. But do we really know why this has happened? A deftly written and enjoyable read, "The Chilling Stars" outlines a brilliant, daring and undoubtedly controversial new theory that will provoke fresh thinking about global warming. As prize-winning science writer, Nigel Calder and climate physicist Henrik Svensmark explain, an interplay of the clouds, the Sun and cosmic rays - sub-atomic particles from exploded stars - seems to have more effect on the climate than manmade carbon dioxide. This conclusion stems from Svensmark's research at the Danish National Space Center which has recently shown that cosmic rays play an unsuspected role in making our everyday clouds. And during the last 100 years cosmic rays became scarcer because unusually vigorous action by the Sun batted many of them away. Fewer cosmic rays meant fewer clouds and a warmer world. The theory, simply put here but explained in fascinating detail in the book, emerges at a time of intense public and political concern about climate change. Motivated only by their concern that science must be trustworthy, Svensmark and Calder invite their readers to put aside their preconceptions about manmade global warming and look afresh at the role of Nature in this hottest of world issues.

Product Details

• Amazon Sales Rank: #141547 in Books
• Published on: 2007-02-15
• Original language: English
• Number of items: 1
• Binding: Paperback
• 256 pages

About the Author
Henrik Svensmark leads a group examining the Sun's effects on the climate, at the Danish National Space Center in Copenhagen. He has published 50 scientific papers on theoretical and experimental physics, including six landmark papers on climate physics. Nigel Calder has spent a lifetime spotting and explaining the big discoveries in all branches of science. He served his apprenticeship as a science writer on the original staff of the magazine New Scientist and was the magazine's Editor from 1962-66. Since then he has worked as an independent author and TV scriptwriter. He won the UNESCO Kalinga Prize for the Popularization of Science for his work for the BBC in a long succession of 'science specials', with accompanying books. His most recent book is Magic Universe (OUP, 2003), a comprehensive guide to modern science, which was shortlisted for the Aventis Prize for Science Books.

Customer Reviews

So what did (does?) cause ice ages?
Henrik Svensmark's theory is that high-energy cosmic rays originating in the destruction of stars in other parts of our galaxy substantially explain the changes in the world's temperature throughout its history. Ice ages and hot periods, as well as shorter lived warming and cooling events (like the Mediaeval Warm Period and the Little Ice Age) are explained by the combination of our solar system's proximity to areas in the galaxy where cosmic activity is highest and the cycle of our Sun's magnetic activity (and thus its ability to protect us from those rays). How? Such cosmic rays - charged sub-atomic particles - stimulate the creation of low-level clouds, and those clouds cool the Earth by reflecting heat back into space. Svensmark does not duck the issue - he states that this effect explains most warming and cooling, leaving only a secondary role for changes in CO2, however caused. Such warming that has occurred over the last century was caused by unusually high magnetic activity of the Sun keeping cosmic radiation away, meaning fewer clouds and a warming world.

This book is written by Svensmark and Nigel Calder, a scientific journalist. It is highly readable and the science well explained. The book is made easier by the fact that the argument is explained in the overview at the start, and each chapter is preceded by a short summary. One quibble is that although there are chapter references at the back, it is not possible to identify the origin of all the bold assertions Svensmark and Calder make.

Svensmark has had his scientific critics; many are catalogued by name. Many, such as Bert Bolin, a Swedish professor of meteorology and member of the IPCC, abused his developing theory because it was "naive and dangerous" - it did not comply with the developing consensus that global warming is man made through the agency of CO2, and that to deny this was to encourage further complacency by self indulgent politicians and ordinary folk. Such attempts to stifle research do not reflect well on the scientists involved. The book gives the impression that he has won over many outright critics and many other scientists who similarly sought explanations for global temperature changes in extra-terrestrial sources but who posited different mechanisms.

Certainly, if you are inclined to wonder, there is ample evidence that Svensmark is working with many scientific colleagues - he is no lone crank - and even where he is not actively working with others his theories have found supporting evidence from other work in other fields - including work that was being undertaken without any obvious connection to climate change research. Although primarily a theoretical physicist, he conducted experiments in the basement of his Danish National Research Centre, apparently demonstrating the cloud forming effectiveness of muons, or high-energy electrons. It seems to me that he and his colleagues have made their case well, quite the contrary to the impression given by Inge Brede Johannessen below. Nor, Mr Listen, is there anything remotely polemic about it! In 2010 an experiment at CERN may provide further evidence of the physics of the basic process. But for the global warming consensus this experiment, originally devised by another scientist and blocked, the book suggest, by physicists unwilling to expose themselves to the criticism of the global warming consensus, might have taken place five years ago.

If your mind is open to the questions (a) is the planet warming? And, if so, (b) why? and (c) how much? then this is a book for you. The science is not that difficult to understand, though if you are a layman like me then you have I think to be modest enough to admit that you probably couldn't identify any scientific howlers in the book, let alone in the Svensmark and colleagues' scientific papers listed in the back. As I write the world's great and good have jetted off to Bali to discuss climate change "mitigation", and most of that mitigation will involve restricting CO2 emission. As others such as Bjorn Lomborg have pointed out, the cost of such a restriction may be the loss of much of the economic growth, and the alleviation of poverty, that would otherwise happen. It is always worth considering whether we have identified the right enemy - or even whether there is an enemy at all. Besides, we all know about ice ages: have you ever wondered what actually caused them?

Excellent analysis of climate change and its causes
Henrik Svensmark, director of the Centre of Sun-Climate Research at the Danish National Space Centre, and Nigel Calder, the well-known science writer, have produced a challenging book on climate change.

When stars die, they do so in supernova explosions that emit cosmic rays, which create ions, which form clouds. Low clouds - less than 3000 metres above the surface - keep the planet cool. The less active the sun is, the more cosmic rays get through to the earth, and so the more clouds there are to cool the earth.

The Danish National Space Centre's SKY experiment showed how cosmic rays set free electrons which then catalysed the clubbing together of sulphuric acid molecules, the most important source of condensation nuclei. These cosmic rays have varied since the world began; their influx depends largely on where the earth is in the galaxy in our orbit around the centre of the Milky Way. When the earth is in dark regions with few stars where the rays are scarce, the climate is warm. When the earth is in bright regions where the rays are intense, the climate is cool.

The medieval warm period of 1000-1300 was followed by the cool periods of 1300-60 and 1450-1540, and a worse one, the little ice age of 1645-1715, then another cool period in 1790-1820. The peak of the little ice age was 1700, which coincided with the Maunder Minimum, when the sun's magnetic activity was very low, reducing its ability to shield the earth from cosmic rays.

In the last century, the sun's magnetic field doubled in strength, reducing the cosmic rays and so the clouds, thus heating up the earth by 0.70C from 1900 to 2005, 70% of the 20th century's warming. The authors predict that global warming in this century is likely to be at the low end of the Intergovernmental Panel on Climate Change's forecast of a 1.80C-40C rise by 2100.

Indeed, temperatures have not risen since 2001, even though global CO2 emissions have been rising faster than ever. Also, the Antarctic's area of sea ice grew by 8% between 1978 and 2005.

An Interesting Theory
I bought this book as I wanted to read an alternative to the idea that global warming is caused by man-made greenhouse gases. Yet I didn't want anything written by someone paid for by the oil industry or some lunatic who thinks the whole thing is a hoax. This book fitted the bill nicely. Henrik Svensmark has developed an extremely interesting theory although its too early to determine its validity. The basis of it is that the sun determines much of climate variability, not simply through the heat energy it delivers but through its radiation field that counteracts cosmic rays that help with cloud formation. When the suns magnetic energy is high, less cosmic rays reach earth, fewer clouds develop and the earth heats up. The science of cosmoclimatalogy is in its infancy, the majority of work having only been accomplised in the last ten years. It has CERN interested enough to provide the resources to create experiments mimicking the effects of cosmic rays. These should be taking place by 2010 and I shall follow them with interest. However there isn't nearly enough here yet to dismiss made made global warming theories (and Henrik Svensmark doesn't deny this effect only questions it extent) but it does provide an alternative view.