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Scientists Agree on Global Warming
Kryptonomic writes: "This might be interesting news in the light of the previous Slashdot article on global warming. On Thursday the UN's International Panel on Climate Change released a damning report warming that the global warming is happening at a much faster rate than previously predicted. In this report the world's most distinguished meteorologists also give their unqualified backing not only to the argument that global warming is happening faster, but also that it is definitely due to human activity."
Smog comes primarily from a combination of heat and car exhaust. Dallas wasn't "more polluted" than Los Angeles by a long shot, but southern California was unseasonably cool, and Texas was unseasonably warm. Hence, more smog. You're not a democrat huh? I take it you must be a member of the green party or the socialist party then. Like it or not, we have to get our oil from somewhere, and the same people that were bitching about rolling blackouts and too high energy prices are usually the same ones bitching about offshore drilling and drilling on the ANWR. Personally, I'm glad California is suffering rolling blackouts. Serves 'em right for being dumb enough not to build any new power plants for 10 years ("we're going to conserve our way to energy independence!"). As far as Bush and his governorship goes, the Texas governorship is probably the weakest one out of all the 50 states. The lieutenant governor holds all the power and sets the agenda. So blaming Bush for problems in Texas is sort of like blaming Queen Elizabeth for England's problems. Its convenient but not altogether accurate.
The popular image that scientists dispense "facts" is simply wrong! The product from scientific activity is "explanations", not "facts". Sometimes those explanations are pretty good, and allow you to make good predictions. In climate science the goal is to explain climate around the world and throughout history; there are a lot of "facts" there that need explaining: why is the Sahara a desert? Why ice ages? Why is the temperature in San Francisco always somewhere around 65 degrees? Why in particular were the 1990's the warmest decade in 1000 years? Some of these "facts" may be explainable by other means (for example, there are arguments that the warming trend in measurements is an illusion caused by where the measurements are being taken). But gradually, within the body of scientists working on these problems, after years of rational debate between competing concepts and explanations, consensus starts to form about which groups of explanations explain the most and are the most consistent with the facts.
Now in other sciences, say physics or chemistry, when such a consensus is reached about, for example, the concept that atoms are real objects and not mere mathematical conveniences, experience has shown that these concepts give us great power in predicting and manipulating the world around us. Somehow the nature of these rational debates within science is such that we actually do uncover something fundamental about the real world when we settle on such explanations. But at the point when "consensus" is reached, it's sometimes hard for any given scientist to enumerate all the reasons why one explanation is better than a competing one. And adherents of the competing, particularly older, explanations generally hang on for years after the consensus has shifted. So it's easy for an outsider to come in and say "look, these scientists don't have any idea what they're talking about - they've never seen an atom, they even tell us it's impossible to see one - and here are ten expert scientists with dozens of respected publications who categorically say there's no such thing as an atom."
But despite the opposition, the consensus group makes predictions based on their explanations, confirms them (or not) with later experience, and over the years gains confidence in those predictions. This is the fundamental rational process by which science works, and it is hard to deny its overall reliability.
Now, given that, should a preliminary explanation, still disputed by some segment of a scientific group, be used to influence public policy? In some respects one could give the predictions a percentage likelihood of being correct - the consensus group would probably run close to 100%, the naysayers close to zero - what if you average the two using the number of proponents of each view. Ok, there you have a rough idea - the predictions on global warming have (by this method using some made-up numbers) a 65% chance of being correct.
The question then is - is a 65% chance of major climate catatsrophe enough for us to change our ways? In Europe and much of the rest of the world, that question has been answered "Yes". Only in the US does it seem we need 99% certainty of major disaster before we do anything. Or am I wrong?
Energy: time to change the picture.
One scientist puts a curve on the overhead saying "this proves conclusively that the climate is warming up", the next puts another curve on the overhead saying "yes, I am of course aware of those data, but they do not take into account that [something], but the following data does". The first comes up with another graph "saying, yes, I understand that analysis, but it ignores that", and then the scientists continue for hours to throw curves at each other, each more convincing to themselves, but less convincing to the audience.
The last time I was to such a debate, it ended when one of the IPCC folks managed to throw a well-known forgery on the overhead. He was caught, and that concluded it.
My position is that climatologists severly underestimate the uncertainty in their statements (as do many other physicists, my own field is severly plagued by it as well).
Are you really sure about that? It is very easy to swing public opinion in any direction. It wouldn't be hard to tell people that we need to pour out more CO_2 to prevent the next ice-age, if you had the PR machine to do it. Well, I call myself an environmentalist, and I feel that in the current situation, you'd better make very sure the things you do, don't cause more harm than good. And the only way to do that is to make sure everything you do rests on solid science. What the IPCC has today just isn't it.
Employee of Inrupt, Project Release Manager and Community Manager for Solid
Some of the highly counter-intuitive effects (described below) of global warming may not be appreciated without an understanding of the contribution made to climate by the Earth's oceans.
Simply because the world's seawater stores millions of times more heat than the atmosphere, and the warm sea currents from tropical oceans transport some of this heat to northern continents like the USA and Europe which would otherwise be permanently freezing cold due to their northerly latitude. Warm sea currents are vital to agriculture and our continued well-being.
Yes, the warm sea currents that keep the planet warm have an Achilles heel -- sea currents stop moving if the saltiness of the seawater falls be low a critical level (the density of seawater depends on its saltiness, reduced-salt seawater won't sink as it normally does in the coldest polar regions, and without sinking seawater the ocean currents stop moving).
One of the agreed effects of increasing Carbon Dioxide emissions is that rainfall will increase in northern latitudes, diluting the seawater. In the limit dilution shuts down the warm sea currents.
The Gulf Stream is the most important warm sea current because it can alter worldwide climate by various positive feedback mechanisms. The climate and food production of the USA and Europe, for example, both depend on the Gulf Stream keeping the climate warm enough to grow crops.
The Gulf Stream is known to be sensitive to changes in rainfall over the Atlantic. Rahmstorf's bifurcation model of Atlantic thermohaline circulation is widely accepted by independent scientists. This model implies the Atlantic Ocean has only tw o stable modes of circulation -- ON and OFF. The Atlantic Ocean is currently in the ON mode with an active Gulf Stream. 100000 years ago, it went into the OFF mode when the Gulf Stream shut down causing a worldwide massive Ice Age. The model shows the likely cause of the shutdown was increased rainfall.
The Gulf Stream changes slightly in intensity from year to year, but overall its average state in recent decades is stable and active. However, the situation should be monitored closely because it is unknown exactly how much additional rainfall the Gulf Stream can tolerate without shutting down. The Rahmstorf model predicts a critical threshold of about 1Sv/yr (10^6m/yr) (sustained increase) which is ~50% above current long-term average rainfall, whereas rainfall over Northern Europe has actually been increasing only by about 2% a year over the last 20 years -- a total rise of 40% which is currently below the 50% threshold. Conclusion: the Gulf Stream looks safe now but vulnerable to future rainfall increases.
Most agricultural plants probably wouldn't survive. The summer air temperature in the US Mid-West, for example, would be just 32F(0C) which would stop all agricultural production.
The ORNL has researched the types of vegetation in the US in present-day conditions and in zero-Gulf Stream conditions.
Scroogle
Satellite temperature records don't reflect the measurements on the ground. Nobody knows why yet, but what are you going to put more stock in: records from physical thermometers (a very well-understood measurement system) on the ground where people, crops and wildlife exist, or satellite radiometers which give discrepant readings from the physical thermometers for unknown reasons and may be giving some kind of systematic error that is not yet understood? My money's on the mercury, not the infrared.
MJ, please stop parroting the SEPP/GEC party line that human activity isn't warming the climate, and on the minuscule chance that it is it isn't doing any harm to our interests. Sure, we don't know what the climate will be like in 100 years. What I do know is that we are far less likely to have unwanted, undesirable and destructive changes in it if we avoid altering the atmosphere's infrared transparency before we have a solid understanding of the way it behaves. Better safe than sorry, you understand.--
Scientists restrict study to entire physical universe; creationist
Way to go, BBC! Glad to see sensationalistic journalism is alive and well in areas other than the US. Call me a troll or mod this down as flamebait if you must, but I just can't stand bad reporting like this.
Co-chairman of the panel, Sir John Houghton "The 1990's were the warmest decade in the Northern Hemisphere for the whole millennium"
That's probably true. Indulge me in speculation that August will be the hottest month this summer... Doesn't the climate vary anyway? And I'm not talking about the annual variations in temperature, or even ones in the scope of 1000 years. Think of cycles in the tens to hundreds of thousands of years folks.
The BBC's Susan Watts "It's the American people who are the chief culprits in pumping global warming gases into the atmosphere"
I like it when a news source quotes it's own reporters for use as supporting material. And as a red-blooded American, I just can't wait to get home and fire up the pollution machine I've got rigged up on my roof. Puh-leeez.
Keith Shine, meteorologist "The overwhelming majority of people accept the evidence that the climate has warmed up"
The climate *has* warmed up, at least in terms of geologic time, and I'll go wayyy out on a limb and go along with the possibility that many people accept this. I guess this is rock-solid evidence in support of whatever point the BBC is trying to make.
Dr Robert Watson, IPCC Chair "We could conceivably be over-estimating the effect of human activity on the Earth's climate, but alternatively we could also be under-estimating it"
Aha. Glad they pulled a null statement like this out into it's own colored box for emphasis. Sadly, this is perhaps the most credible quote made in the entire article.
"We know enough to say climate change is a serious environmental issue," said Dr Watson.
Finally, the voice of reason. Here's another tip: cash-flow is important to the state of your personal finances.
[picture caption] Industrial pollution is the main offender
Hold on now - isn't that a cooling tower? If chemical or particulate matter is being emitted from that, there are a few engineers with a lot of work to do. On the other hand, if all those nasty cooling towers are actually producing enough thermal energy to melt the ice caps and affect the salinity of the planet's oceans, then somebody really designed some inefficient power plants... And correct me if I'm wrong, but are those windmills I see in the background?
It's not as if the BBC needed to fill inches on a page to justify their ad rates, right? So why was this article even written? It could have been about three sentences long, and made its legitimate points better. At least I can't pick on them for mixing up the depletion of the ozone layer with all of this...