The blackboard in Prof. Nir Shaviv's office in the Department of Physics at Hebrew University is covered with equations and graphs. He's hunched over the computer, searching for another illustration, another study that will underscore the subject of our talk: the effect of cosmic rays on the earth's warming.
Shaviv is the preeminent Israeli scholar among a handful throughout the world who believe that human beings are not responsible for global warming. The consequences of global warming were portrayed in Al Gore's successful 2006 film, "An Inconvenient Truth," which presents a frightening scenario to which one can hardly remain indifferent: giant ice caps melting, vast areas of human settlement covered by seas that overflow their banks, fierce hurricanes, new strains of bacteria, plagues and death.
The United Nations Intergovernmental Panel on Climate Change (IPCC) considered the most authoritative body on environmental issues, stated in its 2007 report that the earth's temperature has risen by 0.74 degrees Celsius over the past century. The panel predicted that by the year 2100, the earth's temperature could rise by another 2-4.5 degrees. Most of the world's scientists share the belief that there is a correlation between the rise in temperature and the rise in the amount of carbon dioxide and other greenhouse gases derived from the burning of fossil fuels, from power stations that use petroleum or coal, from auto emissions, factory smokestacks and more.
Shaviv refuses to get worked up: "The hysteria surrounding the concept of 'global warming' will fade over the years," he says. "People will see that the apocalyptic forecasts are not coming true. Today there is no fingerprint attesting that carbon dioxide emission causes a rise in temperature. A Grad missile that falls in Sderot should be more cause for concern." Back to the Ice Age Last Wednesday, Shaviv was featured in a documentary broadcast on Channel 8, "The Cloud Mystery," alongside Danish scientist Henrik Svensmark, a physicist whose pioneering experiments conducted in Copenhagen revealed how changes on the sun's surface and cosmic rays are what affect climate, and not the polluting gases from manmade sources.
A few months from now, Am Oved will be publishing a Hebrew translation of Svensmark's book "The Chilling Stars," which was the basis for the film (and was written with Nigel Calder, former editor of the journal New Scientist). Several important chapters are devoted to Shaviv's work, and as the book's scientific editor, the final drafts of the translation are currently on the desk in his office. Shaviv, 36, is an associate professor at the Hebrew University, in the Racah Institute of Physics, where he lectures on star formation and high energies.
He admits with a little smile that, because of his youth, the librarians at the university sometimes ask to see his student ID. "My age is meaningless," he says. "I always listen to students who come in with a good idea." He lives in Jerusalem with his wife, Hila, who works in biomedical engineering. They are the parents of two sons, Ofek and Lahav. He grew up in Haifa, "in a house of scientists." His father, Prof. Giora Shaviv, is a physicist who once served as dean of the physics faculty at the Technion and president of the Israel Physical Society; his mother, Edna Shaviv, is a professor of architecture and urban construction. As a child he lived and breathed science and also gained a profound awareness of and appreciation for the environment. "I grew up in a 'green' home," he says. "Our house was among the first solar-powered houses in the country. My mother designed it that way. Our house was essentially my mother's experiment at the Technion."
As a boy, he got bored in his science classes at Ironi Heh high school. While his classmates were struggling with exhausting equations, he was devouring the physics books that filled the bookshelves at home. While the other kids his age were gearing up for their matriculation exams, he was finishing a bachelor's degree at the Technion; he earned his master's during his military service in the intelligence corps. He went on to earn his doctorate from the Technion and did postdoctoral work at Caltech and the University of Toronto. He got into the field of global warming by chance. "I like to roam about the world of science," he says. "And if there's something that intrigues me, I research it."
While he was living in Toronto, one of his colleagues asked him how supernovae (the explosion of massive stars) affect the earth. Shaviv examined the question seriously; his conclusions reinforced the argument that charged energy particles called cosmic rays, which are affected by the sun's activity, are what affect the earth's climate. Shaviv explains it as follows: "The sun's activity is cyclical. When it's more active, the wind that blows from it is stronger and then fewer cosmic rays reach the earth. Cosmic rays cause ions to be produced in our atmosphere, which are one of the factors required for the creation of the surface upon which clouds form, primarily above the ocean's surface. When there are fewer ions, the clouds that are formed are composed of large drops. Clouds of this type are less white and refract less of the sun's rays outward, and so the heat is preserved and the earth gets warmer."
In 2002, the prestigious scientific journal Physical Review Letters published Shaviv's article, "Cosmic Ray Diffusion from the Galactic Spiral Arms, Iron Meteorites, and a Possible Climatic Connection." The article was selected by the scientific magazine Discover as one of the year's 100 most important discoveries. In the article, Shaviv proposed the hypothesis that the earth's crossing of the spiral arms of the Milky Way is the cause of the ice ages the planet has experienced. The explanation: When the earth is "traveling" along the Milky Way, says Shaviv, it is exposed to more cosmic rays, in tandem with an increase in supernovae. "When there is a supernova near the earth, it will produce a lot of cosmic rays, which in turn will produce a lot of ionization and the formation of white clouds composed of many small drops of water. These refract the sun's rays outward, which eventually leads to a chilling of the earth.
"The Milky Way is a spiral galaxy with arms," Shaviv continues. "We traverse one of these arms every 145 million years. If the sun's cyclical changes translate into a shift of one degree on earth, then the changes when we traverse such an arm, close to supernovae, will be on the order of 10 degrees, which is a huge amount. When you look at the geological record of the earth, you see that in the past 100 million years, there were periods with ice at the Poles and periods without ice. I demonstrated in the article that the Ice Ages correlate chronologically with our traversing the arms of the Milky Way. In other words, every 145 million years there is an Ice Age. The conclusion is that cosmic rays affect the earth's temperature on long time-scales, too."
Persona non grata At first, Shaviv didn't quite grasp the magnitude of his discovery. "I had no idea that this would lead me to get involved in the greenhouse effect," he says. "All I set out to do was to seriously answer a colleague's question. When I wanted to publish the article I ran into closed doors. I sent the article to Nature and was told - It's nice, but you need to find a stronger basis. After a while, I came to feel like people were always looking for another excuse not to publish the article."
The article was finally published in Physical Review Letters. Not long after its publication, Shaviv came across an article by a Canadian geologist named Jan Veizer, who had made geochemical measurements in order to reconstruct the earth's temperature over the past 550 million years. "One of his aims was to see how the temperature was affected by the amount of carbon dioxide," says Shaviv, "and he found that there was no relation between them. For example, 450 million years ago, it was much colder than it is today, but the amount of carbon dioxide was much, much higher. When he wanted to publish the article, he found it difficult. He was told that his findings couldn't be accurate. That carbon dioxide is known to have a big effect on temperature, so his measurements had to be wrong."
Veizer's geochemical findings fit Shaviv's hypothesis about Ice Ages like a glove. Shaviv hastened to write to him. "He was stunned," Shaviv recalls. "A week later, we met in Toronto at his hotel and we compared my reconstruction of cosmic rays with his temperature reconstruction. We saw that most of the changes on the geological time scales were explained by cosmic rays." Their joint work spawned a new article, published in 2003 in GSA Today under the title "Celestial Driver of Phanerozoic Climate?", looking at climate change over the past 550 million years. The two researchers forcefully argued that the amount of carbon dioxide has, at most, a minimal effect on global warming. This finding, which absolves human beings of responsibility for global warming, aroused stiff opposition.
"Shaviv's view is a minority view," says Prof. Colin Price, head of the Department of Geophysics and Planetary Sciences at Tel Aviv University and one of the strongest critics of the school of thought propounded by Shaviv. "In the scientific world, only a few think as he does. Most scientists, studies and UN reports say that man is to blame for global warming. "The facts show that the earth's temperature has risen nearly a degree since the Industrial Revolution. If you go further back and use chemical methods to examine the earth's temperature, you find that the temperatures in the past did not exceed those of the past 50 years."
Why is a jump of less than one degree so worrisome?
Prof. Price: "I compare it to the normal human body temperature, of 37 degrees Celsius. An increase of one degree is enough to make us sick with fever. It's the same with the earth: Its stable temperature has risen by a degree and that's enough to make it sick. What's unusual and troubling is mainly the rate of this warming. It's all happened in just 50 years. Shaviv argues that it's all happening naturally because of cosmic rays and the sun. We argue that the warming cannot be attributed to a natural cause. If you insert all the things that affect the weather into a mathematical model - the sun, winds, clouds, volcanoes - it's still impossible to recreate the increase in temperature. Something is missing. But if you add to the equation the effect of greenhouse gases, suddenly it all fits. That is, all the models for the study of the subject show that it is not possible to recreate the measurements, to explain the change, solely by means of natural factors."
Shaviv says that his campaign against the consensus has made him "persona non grata in certain communities. The trillion-dollar question today is how much the earth's temperature will rise if we double the amount of carbon dioxide in the air. Contrary to the claim of the IPCC, we said that by 2100 the temperature will rise by less than one and a half degrees. People didn't like it when we showed that the earth's sensitivity to carbon dioxide is low, and we became a persecuted minority."
What does it mean to hold the minority view?
"After I published the article with Jan, we received some furious reactions. There was a group of scientists headed by a German researcher who claimed that everything we did in our study was incorrect. This German fellow, who recruited a few more researchers, published a scathing response in the press. Their attack was fairly ridiculous. He claimed that everything I did was wrong. I put the exchanges between us, which were published in the scientific press, on my Web site at the university. Then this scientist contacted the university and alleged that I was violating his copyright and threatened to sue. Basically, he brought politics into science. Because of this incident, I started a blog, my own private Web site, where I can say whatever I want. I also donated 1,000 euros to plant trees so no one could say I was motivated by outside interests."
Al Gore's film features that famous graph showing a perfect correlation between the rise in temperature and the rise in carbon dioxide. How do you explain that? "There is no proof that the rise in temperature in the 20th century is due to human beings and carbon dioxide emissions. I see two things on the graph: a rise in temperature and a rise in the carbon dioxide level. Gore contends that the rise in carbon dioxide is causing the rise in temperature, and we maintain that the opposite is true - that the rise in temperature is what's causing the rise in carbon dioxide. There are places in the world where scientists have been able to determine the sequence of events, and there we've seen that the change in the amount of carbon dioxide was preceded by a change in temperature."
What about the argument that the amount of greenhouse gases we produce is what traps the sun's rays here and causes warming?
"The point is that no one knows how to calculate it properly. It's true that carbon dioxide warms the planet. But Veizer and I have shown that even if we were to double the amount of carbon dioxide on earth, the temperature wouldn't rise more than one and a half degrees. The UN report, which is based on simulations, talks about an increase of 2-4.5 degrees. Essentially, whoever wrote the report is saying, 'We can't really anticipate by how many degrees the temperature will rise.'"
Al Gore's 'hypocrisy' "The Cloud Mystery" is not the only film in which Shaviv has taken part. Before that, he appeared in the controversial film "The Great Global Warming Swindle." Produced by British television producer Martin Durkin and broadcast on British Channel 4 in March 2007, it featured interviews with senior scientists and academics from the field of environmental studies who voiced doubts about the accepted explanation regarding the connection between human behavior and the greenhouse effect.
The film stirred an outcry and drew sharp criticism. Durkin, who had previously produced a film entitled "Against Nature," attacking the green organizations, accused scientists of being a product of an industry propelled by research money. The green organizations weren't spared this time around either. The film alleges that they are out to promote the use of solar energy and renewable energy, which is much more expensive.
"A few years ago, I, too, would have blamed carbon dioxide," Shaviv says in the movie. "Why? Because I, too, like the rest of the public, believed the media."
Do you agree with the film's ultimate conclusion, with its harsh criticism of the establishment for having "sold" us the whole global warming issue?
"Global warming has snowballed. In recent years, the amount of federal funds that the United States is spending on climate research has climbed to nearly $2 billion. You have to understand how many people are dependent on this money. They can't just come one day and say, 'Oops, we made a mistake. You paid all that money for nothing. This global warming thing really isn't that important.' Deliberately or not, in order to obtain more money, people stress how important global warming is. This is a common sociological phenomenon: Whoever shouts the loudest gets heard. Whoever shouts that the end of the world is nigh is going to be invited to speak in the Senate. And now it's also become very fashionable. So a Knesset member who wants to sound fashionable hitches a ride on this. Never mind that he doesn't possess the tools to go into the issue in any depth."
So Al Gore doesn't know what he's talking about?
"In his movie, he doesn't bring a single piece of proof to show that global warming is due to human beings. He presents his nice graph, which as I said, doesn't prove anything. When I saw the movie for the first time it made me laugh. I knew that what was being said there was meaningless. Their arguments have lasted until now because there were no counter-arguments. And now we come with our argument, that cosmic rays are what cause warming, and they're fighting us tooth and nail. By the way, Gore is a hypocrite. He says that people need to use less fossil fuels - So why does he fly around in a private jet? It's been reported that his monthly electric bill is $1,359. I don't know what somebody could do with all that electricity."
A complaint lodged with Channel 4 claimed that in the interviews with experts in "The Great Global Warming Swindle," comments were taken out of context and the editing was deliberately skewed to buttress a certain viewpoint. Another argument was that the film marked a big success for the oil companies' lobby in its battles with green activists seeking a reduction in greenhouse gas emissions.
"I could direct the same complaints at Al Gore's film," says Shaviv. "The people lodged the complaint before the film was even broadcast, and they lost. All that was shown in the film is legitimate. We live in a democracy and this is how you rouse public opinion."
What about the claim that the oil companies warmly embrace the film and your arguments?
"The oil companies didn't pay Durkin to make the film. They haven't paid me either. Anyone who knows me knows that I care about the environment. My parents brought me up to love the environment, long before any of these people or politicians thought it was worth their while to get into the field. So there are some who say that I'm hurting the green organizations. I've also had people tell me that it might be worth it to sell the standard argument on global warming even if it's false, just for the sake of preserving the green organizations. As a scientist, I don't see any reason to deceive people. There are enough good reasons for prohibiting the use of fossil fuels: air pollution shortens our lifespan, oil is a dwindling resource, the countries that control the oil are not the most sympathetic. Reducing air pollution and the use of fossil fuels should be promoted for the right reasons and not for the wrong reasons." The greens also cite those reasons.
"My problem with green activism is that they're investing an effort in things that aren't real - instead of investing in the important things. Not long ago, they held an 'electricity-free' day in Tel Aviv. An hour in which all electric devices were supposed to be turned off. Come on. They're busy fighting the greenhouse effect instead of closing down a factory that's poisoning the sea. I get more upset when I see someone toss a cigarette out of the car than by the fear that by the year 2100, the earth's temperature will have risen by less than a degree."
In what state do you expect the struggle over global warming to be a decade or more from now?
"This struggle will fade away. In the past, we were afraid of the Y2K bug that was going to paralyze the world, we were afraid of the tail gases of a comet that was supposed to strike the earth - none of this happened. In the last 10 years, the earth's temperature has not risen. Over the last century, it has risen 0.75 degrees. Less than a degree. My guess is that even if we double the amount of carbon dioxide by 2100, the temperature will only rise by one degree, and we needn't be afraid of that."
If we needn't fear global warming, then what is the greatest danger facing humanity?
"Man himself. I'm more afraid of some terror organization getting hold of a nuclear bomb with the aid of a frustrated engineer from the former Soviet Union. I'd definitely be a lot more afraid of living in the south and having to fear that a Qassam rocket is going to fall than of global warming.