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Originally Posted by kittygrrl
Your thoughts. Fiction or Fact?
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At present, I think it would be prudent to accept, at least provisionally, that climate change is happening and that there is good reason to believe that humans are contributing to this. I base this, in part, because one of the rules of the game in science is that you make predictions and if your prediction is born out by observation, you are justified in presuming you are on the right track.
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