Here is an interesting article that was quoted from John Atcheson on the yahoo mesembs group: > Over the past several months, the normally restrained voice of science > has taken on a distinct note of panic when it comes to global warming. > How did we go from debating the "uncertainty" behind climate science > to near hysterical warnings from normally sober scientists about > irrevocable and catastrophic consequences? Two reasons. > First, there hasn't been any real uncertainty in the scientific > community for more than a decade. An unholy alliance of key fossil > fuel corporations and conservative politicians have waged a > sophisticated and well-funded misinformation campaign to create doubt > and controversy in the face of nearly universal scientific consensus. > In this, they were aided and abetted by a press which loved > controversy more than truth, and by the Bush administration, which has > systematically tried to distort the science and silence and intimidate > government scientists who sought to speak out on global warming. But > the second reason is that the scientific community failed to > adequately anticipate and model several positive feedback loops that > profoundly amplify the rate and extent of human-induced climate > change. And in the case of global warming, positive feedback loops can > have some very negative consequences. The plain fact is, we are fast > approaching - and perhaps well past - several tipping points which > would make global warming irreversible. > In an editorial in the Baltimore Sun on December 15th, 2004 this > author outlined one such tipping point: a self-reinforcing feedback > loop in which higher temperatures caused methane - a powerful heat- > trapping greenhouse gas (GHG) - to escape from ice-like structures > called clathrates, which raised the temperature which caused more > methane to be released and so on. Even though there was strong > evidence that this mechanism had contributed to at least two extreme > warming events in the geologic past, the scientific community hadn't > yet focused on methane ices in 2004. Even among the few pessimists who > had, we believed - or hoped - that we had a decade or so before > anything like it began happening again. > We were wrong. > In August of 2005 a team of scientists from Oxford and Tomsk > University in Russia announced that a massive Siberian peat bog the > size of Germany and France combined was melting, releasing billions of > tons of methane as it did. > The last time it got warm enough to set off this feedback loop was > 55 million years ago in a period known as the Paleocene-Eocene Thermal > Maximum or PETM, when increased volcanic activity released enough GHGs > to trigger a series of self-reinforcing methane burps. > The resulting warming caused massive die-offs and it took more than > 100,000 years for the earth to recover. > It's looks like we're on the verge of triggering a far worse event. > At a recent meeting of the American Academy for the Advancement of > Sciences in St. Louis, James Zachos, foremost expert on the PETM > reported that greenhouse gasses are accumulating in the atmosphere at > thirty times the speed with which they did during the PETM. > We may have just witnessed the first salvo in what could prove to be > an irreversible trip to hell on earth. > There are other positive feedback loops we've failed to anticipate. > For example, the heat wave in Europe that killed 35,000 people in > 2003 also damaged European woodlands, causing them to release more > carbon dioxide, the main GHG, than they sequester - exactly the > opposite of the assumptions built into our models, which treat forests > as sponges that sop up excess carbon. > The same thing is happening to a number of other ecosystems that our > models and scientists have treated as carbon sinks. The Amazon > rainforest, the boreal forests (one of the largest terrestrial carbon > sinks in the planet), and soils in temperate areas are all releasing > more carbon than they are absorbing, due to global warming-induced > droughts, diseases, pest activity, and metabolic changes. In short, > many of the things we treat as carbon sponges in our models aren't > sopping up excess carbon; they're being wrung out and releasing extra > carbon. > The polar ice cap is also melting far faster than models predict, > setting off another feedback loop. Less ice means more open water, > which absorbs more heat which means less ice, and so on. > Even worse, we've substantially underestimated the rate at which > continental glaciers are melting. > Climate change models predicted that it would take more than 1,000 > years for Greenland's ice sheet to melt. But at the AAAS meeting in > St. Louis, NASA's Eric Rignot outlined the results of a study that > shows Greenland's ice cover is breaking apart and flowing into the sea > at rates far in excess of anything scientists predicted, and it's > accelerating each year. If (or when) Greenland's ice cover melts, it > will raise sea levels by 21 feet - enough to inundate nearly every sea > port in America. > In the Antarctic seas, another potentially devastating feedback loop > is taking place. Populations of krill have plummeted by 80% in the > last few years due to loss of sea ice. Krill are the single most > important species in the marine foodchain, and they also extract > massive amounts of carbon out of the atmosphere. No one predicted > their demise, but the ramifications for both global warming and the > health of marine ecosystems are disastrous. This, too, will likely > feed on itself, as less krill means more carbon stays in the > atmosphere, which means warmer seas, which means less ice, which means > less krill and so on in a massive negative spiral. > > One of our preeminent planetary scientists, James Lovelock, believes > that in the not too distant future humans will be restricted to a > relatively few breeding pairs in Antarctica. It would be comfortable > to dismiss Professor Lovelock as a doom and gloom crazy, but that > would be a mistake. A little over a year ago at the conclusion of a > global conference in Exeter England on Avoiding Dangerous Climate > Change, scientists warned that if we allowed atmospheric > concentrations of GHG to exceed 400 ppm, we could trigger serious and > irreversible consequences. We passed that milestone in 2005 with > little notice and no fanfare. > The scientific uncertainty in global warming isn't about whether it's > occurring or whether it's caused by human activity, or even if it will > "cost" us too much to deal with it now. That's all been settled. > Scientists are now debating whether it's too late to prevent planetary > devastation, or whether we have yet a small window to forestall the > worst effects of global warming. > > Our children may forgive us the debts we're passing on to them, they > may forgive us if terrorism persists, they may forgive us for waging > war instead of pursuing peace, they may even forgive us for > squandering the opportunity to put the nuclear genie back in the > bottle. But they will spit on our bones and curse our names if we pass > on a world that is barely habitable when it was in our power to > prevent it. > > And they will be right to do so. > > John Atcheson's writing has appeared in the Washington Post, the > Baltimore Sun, the San Jose Mercury News, the Memphis Commercial > Appeal, as well as in several wonk journals. Email to: > atchman@ > > http://www.commondreams.org/views06/0222-27.htm > > http://tinyurl.com/z9fbb/