Global Warming
Your thoughts. Fiction or Fact?
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Hard to deny after this week. I heard on the radio today that most people in the U.S. think it's real, but that it's low on their list of priorities. That's why we haven't heard much about it during the election.
Sandy may have changed that. We'll see. |
I am a geologist by major. My thoughts:
"Global warming" can either mean the natural warming of the planet or the hypothesis that man is destroying the atmosphere and warming the planet by our own actions. Earth has always had climate change, either cooler or warmer, most obviously in the Ice Ages. The Mesozoic era, when the dinosaurs dominated, was actually warmer than we are now. Skipping way ahead to the early Middle Ages, before 1300, they too were a warm period which was historically marked by the first few Crusades, and great journeys and a general leap forward for civilizations. But starting about 1300 and certainly by 1340, we entered what is called the "Little Ice Age". The LIA was much cooler and damper. The poor climate and failed crops left Europe's population a sitting duck for the Black Plague, smallpox, syphillis, and you name it. As an aside, the ravages on society due to these epidemics led to great social change as feudalism collapsed and a new middle class emerged. The Roman Catholic church, though very powerful, found competition in the rise of Protestantism due in part to people's disillusionment with a church powerless against disease. The roots of later revolution in France, the Holy Roman Empire, and ultimately Russia were sewn by governments failing to respond to people in crisis. Obviously, all of these effects had other causes but the climate factor is interesting. The LIA lasted until about 1850, and we've been warming ever since. Realize that the Industrial Revolution, which got going about the same time, only affected a small part of the planet as a whole-western Europe and northeast America. Even today, we actually have more wilderness land in America than we did 60 years ago. Car and industrial emissions are much more tightly regulated than in the 1950's and 60's. So, in short, we are warming but it's my belief that man is not the great influence on it. Call me cynical, but it's worth looking into just what the "scientists" are saying, and following the (big) money involved. I'm all for recycling and using our resources responsibly, of course, but climate change in itself is natural and our main responsibility is not to build in hazardous areas (easier said than done). |
Thank for that info!
i feel it's evolution. Like what guihong just posted, the world is evercharging. i don't understand why people expect the Earth's climate to stop changing. |
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i don't know enough about global warming to know. i've found the info on this thread really interesting because most people i know accept global warming and human involvement in it as fact, so it was really cool to hear a different perspective. it definitely made me stop and think.
i do think corporations are doing a lot of fucked up shit to the environment. i don't know if that's causing global warming, but it's causing enough other problems to scare me. i'm curious for folks who know more about this than i do - what do you think about the theory that we're going through a great extinction that's driven partly by human actions? i heard this (and the idea that we might have another huge volcanic eruption sometime soon) only recently. |
Permafrost in Alaska is thawing..it contains mega amounts of carbon which can form into methane..not good
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I honestly beleave the earth has gone thrue many cyckes of cooling then warming in varying degrees and will contenue to do so.I'm not a scientis but I do read lots of earth/ cutural history and it says thay had happen a lot of times,onething for shure we best be mindful of how our ancestors got thrue the weather changes so we will be able to do the same by inproveing on the how and why they did as well as they did.the satistics of survival of the fitist will be inproved on but useing th technology we have at hand.
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To take just one example, current models (which are imperfect but still have their utility) predicted that we would start losing the Arctic ice cap sometime around 2015. We are pretty much on track for that to happen (we could have no summer ice cap in the Arctic next year or perhaps 2014). To me that looks like a prediction that is being confirmed in real-time. Yes, the planet has been both warmer than it is now and colder than it is now. Yes, our species survived both relatively warmer climates and relatively colder climates. This should not make us quite so complacent, however. The last real ice age almost wiped the species out. We are genetically 'small' which means that for our huge numbers, there should be more genetic diversity than there actually is. This means that our species went through a population bottleneck fairly recently (less than 100000 years ago). My larger concern, aside from parochial concerns about the long-term prospects for our species survival, is that there we are well on our way to being the cause of the sixth largest extinction event the planet has ever seen. That puts us in the company of large asteroid strikes and super-volcano eruptions. Large, complex species can't adapt on a dime and we are not giving species enough time to adapt to the change in climate. The follow-on effects could be pretty drastic. Lose a predator species and suddenly their prey could have a population explosion which could cause further problems as they either expand into human inhabited areas. Am I certain that humans are causing climate change? No, however none of the current alternative explanations, at least none that I've read, are able to account for the rapidity of the change. It's not enough to be able to say "maybe it is a solar cycle" one must be able to explain why the solar cycle explanation is superior to the view that humans are the prime cause and the alternative should also be able to explain any anomalies that the current model cannot. I don't believe that the solar cycle model can explain the Greenland ice sheet loss. cheers Aj |
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My concern isn't with the rise in temperature in absolute terms--provided we don't see serious spikes outside of the normal range that shouldn't be a problem. Rather, my concern is with the combination of the rapidity of change and the degree of change. Six or seven degrees C within a century is a big shift and one that I'm not sure how many species that live in temperate or arctic climes could handle that sort of shift long term. I know that species extinction happens. I know that *mass* species extinction happens. But once we become aware that *we* are causing mass extinctions, I think both prudence and ethics dictate that we at least consider doing something to ameliorate the situation. We can't stop big rocks from hitting the planet (well, maybe we could) but we can stop ourselves from heating the planet so much that we get into a really bad feedback loop and then, a few thousand years from now, some intelligent species, following a faint radio broadcast that could *only* have come from an intelligent species, parks its ship in low-earth orbit and finds that Sol has two very hot, rocky planets with runaway greenhouse effects instead of the one it currently has. Cheers Aj |
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As far as how we might adapt as a species is anyone's guess. We are still evolving as a species but we've changed the rules of the game so much that it's just this side of impossible for us to know what kinds of traits are being selected for. Cheers Aj |
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At the end of Bill Clinton's last term global climate change was accepted by the overwhelming majority of scientists in and out of the field across the world........so was evolution.
It's only in the US there is this denial of climate change and evolution. Frankly I don't give a shit...........what I can see with my own eyes is the ice caps melting, the glacier packs on all the moutains/volcanoes melting rapidly (look at pics of Mt Rainer....it's scarey).....and the pollution being churned out in India and China at alarming rates........there is a problem....a big one. Let's not be more stupid and let's do everything we can to eliminate the human contribution to the problem.....in ALL countries particularly the newly industrialized countries.......... stop basing everything on oil as the provider of energy....we are way smarter than that |
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Certainly. It's not that we had a brush with extinction *because* of our lack of genetic diversity. The small amount of genetic diversity among our species is an *effect* of that brush with extinction not the cause. A few of different things point toward this being the case. The first--and the one which, more or less, gives birth to the other two is that both the mitochondrial DNA variation (I'll refer to this as mtDNA from here on out) and the Y-chromosome variation is less than what we would expect given our numbers. All seven billion of us carry one of seven mtDNA variations. The roughly 49% of humans who care a Y-chromosome are all in some 15 groups. Again, this is smaller than one would expect. For example, chimpanzees have much more genetic diversity and worldwide they don't make up even 1% of human numbers but any two given chimps that are not closely related will share far fewer genes than any two non-related humans will. This kind of anomaly cries out for explanation. Since mutations in all species accumulate at fairly predictable rates once you can work backward and start to see where those genes started and how they radiated out amongst existing human populations. What that work has shown is that every human being alive is related to a fairly small population, of ~10000 breeding pairs, that lived in sub-Saharan Africa in the range of 75 to 100K years ago. The easiest way to think about this is the relationship between you and distant cousins. Somewhere out there are people whom you are distantly related to that you have no idea that you share genes with them. If, however, we sequenced your DNA and their DNA and, assuming we were lucky, had access to all the intermediary DNA we could work backward to where your shared genes come from. In much the same way, although obviously over a much longer time period, with a far larger sample and with lots of gaps in that sample, we can work back where various genes found in populations had their origins. I won't bore you with the mathematics of it but there are certain things that just follow from certain observations. For example, since mtDNA is passed down, pretty much unchanged, from the mother it means that there must have been a mitochondrial Eve (in other words some woman or women who carried the copies of the mtDNA that all humans have). Even though evolution tends to homogenize a population because it favors those genes that work better in their environment, there's a *lot* of genetic diversity that is just missing in our species and the only real explanation for it--given that we know the mutation rate in the species--is that a lot of the diversity was wiped out and then bounced back. Quote:
Because of medicine, with the exception of some disease resistance, I don't know that we are going to be selecting for physical traits as much as we are for mental traits. But it's hard to predict future evolution because nature is far more clever than we are and she knows what she likes. Cheers Aj |
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We tend to underestimate the power of literacy, writing and scientific method, in particular, because they are so ubiquitous and they work so well that they've just become part of the infrastructure of life. Yet these are all very powerful technologies. We wouldn't have to, just to take three examples, reinvent agriculture, steel or bronze working because we've written down how to do those things. It means we can preserve knowledge across generations in a very durable form. Those are the kinds of technologies I was speaking of and should have been more specific about them. Cheers Aj |
So I'm curious, particularly to those who may not believe that climate change is happening, what would it take to convince you? Is there some observation or piece of evidence that you would find compelling? If so, what would that piece of evidence look like?
Cheers Aj |
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I think that almost any of theories could happen. I believe that earth changes are part of evolution and will happen regardless. I believe humans have accelerated the process. Then again some religious crazy group might find a way to end life as we know it. I use to make myself crazy with it all trying to prepare for the worse case. Now I am reasonable prepared, have food storage, solar panels, seeds, guns, ammo and the ability to survive without electric, money or supermarkets. But if some idiot nukes us I probably won't survive radiation or the countless other things that could happen. Today I live in the now as much as possible. I just don't get wrapped up in it. |
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