[Home] [Headlines] [Latest Articles] [Latest Comments] [Post] [Sign-in] [Mail] [Setup] [Help]
Status: Not Logged In; Sign In
Science/Tech See other Science/Tech Articles Title: Will the sun cool us? The Deniers -- Part VII Will the sun cool us? The Deniers -- Part VII Lawrence Solomon, Financial Post Published: Friday, February 02, 2007 Apology To Dr. Nigel Weiss The science is settled" on climate change, say most scientists in the field. They believe that man-made emissions of greenhouse gases are heating the globe to dangerous levels and that, in the coming decades, steadily increasing temperatures will melt the polar ice caps and flood the world's low-lying coastal areas. Don't tell that to Nigel Weiss, Professor Emeritus at the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge, past President of the Royal Astronomical Society, and a scientist as honoured as they come. The science is anything but settled, he observes, except for one virtual certainty: The world is about to enter a cooling period. Dr. Weiss believes that man-made greenhouse gases have recently had a role in warming the earth, although the extent of that role, he says, cannot yet be known. What is known, however, is that throughout earth's history climate change has been driven by factors other than man: "Variable behaviour of the sun is an obvious explanation," says Dr. Weiss, "and there is increasing evidence that Earth's climate responds to changing patterns of solar magnetic activity." The sun's most obvious magnetic features are sunspots, formed as magnetic fields rip through the sun's surface. A magnetically active sun boosts the number of sunspots, indicating that vast amounts of energy are being released from deep within. Typically, sunspots flare up and settle down in cycles of about 11 years. In the last 50 years, we haven't been living in typical times: "If you look back into the sun's past, you find that we live in a period of abnormally high solar activity," Dr. Weiss states. These hyperactive periods do not last long, "perhaps 50 to 100 years, then you get a crash," says Dr. Weiss. 'It's a boom-bust system, and I would expect a crash soon." In addition to the 11-year cycle, sunspots almost entirely "crash," or die out, every 200 years or so as solar activity diminishes. When the crash occurs, the Earth can cool dramatically. Dr. Weiss knows because these phenomenon, known as "Grand minima," have recurred over the past 10,000 years, if not longer. "The deeper the crash, the longer it will last," Dr. Weiss explains. In the 17th century, sunspots almost completely disappeared for 70 years. That was the coldest interval of the Little Ice Age, when New York Harbour froze, allowing walkers to journey from Manhattan to Staten Island, and when Viking colonies abandoned Greenland, a once verdant land that became tundra. Also in the Little Ice Age, Finland lost one-third of its population, Iceland half. The previous cooling period lasted 150 years while a minor crash at the beginning of the 19th century was accompanied by a cooling period that lasted only 30 years. In contrast, when the sun is very active, such as the period we're now in, the Earth can warm dramatically. This was the case during the Medieval Warm Period, when the Vikings first colonized Greenland and when Britain was wine-growing country. No one knows precisely when a crash will occur but some expect it soon, because the sun's polar field is now at its weakest since measurements began in the early 1950s. Some predict the crash within five years, and many speculate about its effect on global warming. A mild crash could be beneficial, in giving us Earthlings the decades needed to reverse our greenhouse gas producing ways. Others speculate that the recent global warming may be a blessing in disguise, big-time, by moderating the negative consequences of what might otherwise be a deep chill following a deep crash. During the Little Ice Age, scientists estimate, global temperatures on average may have dropped by less than 1 degree Celsius, showing the potential consequences of even an apparently small decline. Dr. Weiss prefers not to speculate. He sees the coming crash as an opportunity to obtain the knowledge necessary to make informed decisions on climate change, and the extent to which man-made emissions have been a factor. "Having a crash would certainly allow us to pin down the sun's true level of influence on the Earth's climate," concludes Dr. Weiss. Then we will be able to act on fact, rather than from fear. Lawrence Solomon is executive director of Urban Renaissance Institute and Consumer Policy Institute, divisions of Energy Probe Research Foundation. CV OF A DENIER: Nigel Weiss, professor emeritus of mathematical astrophysics in the University of Cambridge, discovered the process of "flux expulsion" by which a conducting fluid undergoing rotating motion acts to expel the magnetic flux from the region of motion, a process now known to occur in the photosphere of the sun and other stars. He is also distinguished for his work on the theory of convection, and for precise numerical experiments on the behaviour of complicated non-linear differential equations. Nigel Weiss is a recipient of a Royal Society Citation, he is a past President of the Royal Astronomical Society, and a past Chairman of Cambridge's School of Physical Sciences. He was educated at Clare College, University of Cambridge. The limits of predictability The Deniers -- Part VIII Lawrence Solomon, Financial Post Published: Friday, February 02, 2007 January 19, 2007 When Frans Nieuwstadt, a distinguished Dutch meteorologist, engineer, editor and professor, died in 2005, his obituary recounted seminal events in his accomplished life. Among the experiences worthy of mention: Nieuwstadt had studied under the celebrated professor, Henk Tennekes, and along with other colleagues had been instrumental in convincing Tennekes to return to Europe in 1978 to become director of research at the Royal Netherlands Meteorological Institute and later chairman of the august Scientific Advisory Committee of the European Centre for Medium-Range Weather Forecasts. Henk Tennekes, in ways both personal and professional, has touched an extraordinary number of lives in his own distinguished career, among academics and laymen alike. He is loved for his popular 1997 book, The Simple Science of Flight From Insects to Jumbo Jets, and for his scholarly 1972 work, A First Course in Turbulence, a classic that logs more than 2,000 citations on Google Scholar. His provocative 1986 speech, "No Forecast Is Complete Without A Forecast of Forecast Skill," led to the now-common discipline of "ensemble forecasting" and spurred "multi-model forecasting." Scientists today continue to wrestle with the fundamental critiques that he first presented. Tennekes became more than an inspiration for his students and a model for other scientists, however. He also became an object lesson in the limits of scientific inquiry. Because his critiques of climate science ran afoul of the orthodoxy required by the Royal Netherlands Meteorological Institute, he was forced to leave. Lesser scientists, seeing that even a man of Tennekes's reputation was not free to voice dissent, learned their lesson. Ever since, most scientists who harbour doubts about climate science bite their tongues and keep their heads down. Tennekes, more than any other individual, challenged the models that climate scientists were constructing, saying models could never replicate the complexity of the real world. What was needed was a different approach to science, one that recognized inherent limits in such scientific tools and aimed less to regulate the environment. In a landmark speech to the American Meteorological Society in 1986, he argued that meteorology was poised to be the first of the post- Newtonian sciences because it was "at odds with the mainstream of the scientific enterprise of the last 300 years. One goal of science is to control nature, but we know we cannot control the weather. The goal of science is prediction, but we stand in front of the limits of predictability." Meteorology, in other words, would be the first scientific discipline to hit this brick wall. As Tennekes argued, modern theory "unequivocally predicts that no amount of improvement in the quality of the observation network or in the power of computers will improve the average useful forecast range by more than a few days." Since Tennekes' speech, a host of scientists have sought to extend the bounds of modelling. They have seen success, but only on the scale Tennekes predicted. In a paper presented in 2003, a team of European scientists detailed advances in modelling science. "Since the day, almost 20 years ago, in which Henk Tennekes stated ... that 'no forecast is complete without a forecast of the forecast skill,' the demand for numerical forecasting tools ... has been ever increasing," they said, explaining efforts to make modelling reliable beyond a three- to four-day period. Thanks to the intense efforts of a new generation of climate modellers, modelling capability has advanced in some instances by 12 to 36 hours, in others by several days. To extend the bounds further, the paper announced a major new research initiative, designed to bring the forecasting discipline to the 120-hour range. Climate modelling is the basis of forecasts of climate change. Yet this modelling, Tennekes believes, has little utility, and "there is no chance at all that the physical sciences can produce a universally accepted scientific basis for policy measures concerning climate change." Moreover, he states: "There exists no sound theoretical framework for climate predictability studies." Not surprisingly, Tennekes abhors the dogma that he feels characterizes the climate-change establishment, and the untoward role of climate science in public-policy making. "We only understand 10% of the climate issue. That is not enough to wreck the world economy with Kyoto-like measures." Lawrence Solomon@nextcity.com
Post Comment Private Reply Ignore Thread Top Page Up Full Thread Page Down Bottom/Latest
#1. To: richard9151 (#0)
Ok I have a problem. I don't get pings when a co-owner pings my list. At LP this was because you had to add yourself to the list in order to get pinged. I can't seem to add my self to the list. Very odd. Edit: never mind. It wouldn't let me add the name directly but would let me check the box. That worked. Sigh. You have to be smarter than the program I guess.
|
||
[Home]
[Headlines]
[Latest Articles]
[Latest Comments]
[Post]
[Sign-in]
[Mail]
[Setup]
[Help]
|