Thursday 18 May 2006 — This is over 18 years old. Be careful.
The ongoing debate about global warming fascinates me, and one of the more interesting questions is how scientists determine that human actions are the cause. Many conservatives seems bent on chalking it up to natual cycles. So it’s interesting to see the Wall Street Journal publishing Scientists Explain How They Attribute Climate-Change Data. It’s a quick (too quick) overview of the ways scientists rule out various explanations for the warming being observed, and conclude that it is human action after all.
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That's why, with glaciers and sea ice melting and rainfall patterns shifting, scientists smell a stacked climate deck. "We have never seen natural variability on a global scale like we've had in the last 100 years," says atmospheric physicist Michael Oppenheimer of Princeton University.
For me, that type of absolutism is just a little tough to swallow. Even if you go by nothing more than what has happened in the last 1000 years, you will see there have been drastic changes to the Earth's climate that could not have been caused by humans. There is a valid reason why Greenland was given it's name. The Vikings had settlements there for a number of years before the climate turned colder and the summers there all but disappeared.
We are constantly bombarded by comments about how the glaciers are retreating. But are they retreating everywhere or are they advancing in some places? And if so much ice is melting, shouldn't the sea levels be rising? I haven't heard of that happeneing anywhere.
I just thing that it's awfully arrogant of us to believe that we can do so much damage in 300 years when the Earth has been here for over 4 billion years. And as much as we think we know about climatology, how sure are we that our theories and guesses are really correct?
In the end, I want to see cold, hard data showing me that the Earth is warming up everywhere, consistently. Until that time, I will take what they have to say with a grain of salt, just like I do with all statistics.
Sean---
I don't think you'll ever see data showing that the temperature everywhere in the world is rising; our weather system doesn't work like. Global *average*, sure -- but there will always be some places that get cooler; for example, I'm sure some deserts will be vanishing as the oceans rise.
As for the bigger question -- science, like anything else, rarely offers surety. Certainly the data predominantly points to global warming; the conclusion that it's due to human effects is robust, I think, but I'm less familar with the arguments there. In this case, I'm trusting people I personally know to be intelligent, thoughtful experts. I'm not sure what a good solution is for people who don't know such experts personally ;).
The real danger with demanding personally observable effects like a general rise in sea level is that by the time you see & believe, it may be too late to do much about it. Go visit a glacier some time, and see how much of it has vanished in the last 10 years -- that might turn you into a believer!
Finally, remember that we're not really doing all that much damage to the Earth. We're just doing damage to ourselves and many other species! That's happened a bunch of times over the last 500 my, but my guess is that most people don't want it to happen again. At least not in their lifetime.
--titus
Be Alert before the situation goes out of control!!!!
Okay, sure, whatever. That makes sense.
The part I have trouble swallowing is that we've been able to observe "a zillion poker hands" with such high levels of confidence.
Radical changes have been constantly occurring on Earth as long as it has been around. Is it more arrogant is it that we believe that the last 400 years of human existence could do more to change the climate than nature or to think that the changes that are occuring have nothing to do with us? They both have negatives to them and absolute belief in either is wrong. Just as an example, an article on MSNBC http://www.msnbc.msn.com/id/12721432/ talked about the radical changes that occurred between 13,000 and 11,000 years ago in North America. Those changes caused the extinction of the mamouths and wild horses. Aside from over hunting by over zealous aristocrats, can scientists point to any similar extinction that has occurred over the last 2000 years? Certainly not in the last 200 years.
Is Global Warming a viable theory? Absolutely. Is it a provable Law? Not even remotely close.
Sean---
Conservatives are no more or less prone to believing this than 'progressives' are bent to blame human action for all warming. In fact, christian conservatives are rather big on man-made warming - hence the appeal of this line to someone like Senator McCain, to rally both them and moderate Democrats at one stroke - while the pro-business crowd goes the other way. Same thing on the left, where trade-union types are not so hot on it - no pun intended - while others stopped asking questions years ago. This one cuts across politics and probably will for quite a while.
But politics aside, warming is still a lot more controversial among scientists than the article lets it. Especially when it comes to making 100-year predictions based on computer models which derive future temperatures not from raw physics but from long-range economic simulations, causing no end of arguments as to what the right set of assumptions and variables should be.
But then, we wouldn't read or need articles like these if this weren't deeply controversial, would we ?
Well, pumping or digging up and then burning the concentrated remains of several million years' worth of dead plants and animals could certainly make those 400 years count. But is it arrogant to think that humans can disturb the environment more than natural cycles and events? I don't think we should so easily underestimate our effect on the natural world, labelling it as an unjustified sense of self-importance: damaging the ecosystem isn't something to be proud of - so there are no bragging rights in climate science - and if we're a significant agent in such a negative development we should recognise our role, not choose to deny it on the basis of a false sense of humility.
Sure, big things have happened to the planet that make even recent climate change look insignificant, but the big difference between those things and global warming is that it doesn't take a dinosaur extinction event to have disastrous consequences on human society. We have to tread carefully because the margins around the civilisation we know are so small.
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