|Quoting Mike89406 (Thread starter):|
Me and my physics professer at Embry-Riddle University were discussing global warming he is a PhD Environmental Engineering and he said that the movie "The Convienent Truth" showed people the falling iceburgs, glaciers etc. on only a 5% landmass while tha was going on the other Icecaps were growing in places like antarctica or other parts of the arctic. There was also that GW is occuring much faster than they predicted but reputible scientists say we dont know how fast its occuring so the people who are saying that we'll be covered by 2080 or whatever dont really know. Also my professer said that scientific models are inaccurate they're getting better but nowhere near able to predict the real timeline etc...Also the majority of scientists dont necessarily agree that everything is as bad as they say, however they probably came to a consensus and are pushing this issue just to be on the safe side (Doesn' mean they're always right)
I've also heard that there was 3 warming trends in the 20th century alone one more significant than present day. Also there are increased Co2 emissions with the warming up not necessarily just because of cars and jets. Now I'm willing to concede that there is something going on maybe pollution, even sopme GW but not like they potray etc... but can these massive media scares just be what it is? Lastly I will leave you with the article I seen this today although it seems to me that these crazy artciles and GW topics run rampant on AOL
There have been many 'natural' warming/cooling trends since the last Ice Age, for sure. About 5K yrs ago, it was so hot in the northern plains that the aboriginal people left during the summers and migrated north or into the alpine areas, for example. The Little Ice Age cooling trend that drove the Vikings from Greenland only ended about 200 yrs ago and it's been getting warmer ever since. But the rate of warming has accelerated noticeably since the end of WW1.
There's no actual consenus on the reasons for this. The models have big gaps in them due to the complexity of the environment and the lack of really good data going back centuries, although much can be gleaned from ice core samples. This can give you at least a rough 'big picture' data point on temperatures from isotopic ratios, for example.
Part of the GCC (global climatic change) theory is that we will see much more variability in conditions around the world. As your prof pointed out, icecaps can be shrinking in one area and growing elsewhere. However the _trend_ globally seems to be pointed towards shrinking.
|Quoting Aloges (Reply 2):|
But please consider the effect rising temperaturess can have on vegetation, both marine and on land. Google for the effects on e.g. coral reefs which are vital ecosystems for millions of people; if only for being wave barriers. Then look for permafrost soil in relation to global warming. There's also a significant effect on the stability of alpine rock formations, which may not seem all that dramatic to someone from Florida but still has a nasty catch to it. Mountainsides crashing on Swiss highways aren't fun.
Re: alpine rock. Quite so. In fact the current edition of "Canadian Geographic" has a very interesting article on this very subject.
|Quoting Rara (Reply 3):|
I think you raise some good points. Fact is, climate is a very complex thing; we can attempt to understand it and make presumptions and predictions based on our models, but we can never be absolutely sure. There's one indicator that speaks for our knowledge: most of our models say, the earth will get warmer; empiric evidence shows that it does. That's an indicator that our models could be true (but the reason could lie elsewhere, of course).
Global climate modelling is very difficult. Much depends on cell size for the predictions, for example. There is a tremendous amount of inter-relationship between current conditions, rends, and future conditions. The effect of feedback among, say, 20 or 30 parameters, is quite difficult to model -- I know this from modelling nuclear reactor response to accident situations.
Consider, however: if we conclude that human activity is _not_ the primary driver for the GCC effects we are currently seeing, and we determine in 2050 or 2060 that we're wrong. By then it will probably be too late to halt or reverse the effects, and then it will be every country, or every person, for themselves. The cautionary principle should direct us towards taking the path that impacts the global ecosystem the least that is practical consistent with maintaining our presence here in some kind of decent standard.
The IPCC report recently issued was a consensus report which, bluntly put, was a 'lowest common denominator' standard simply to get the damn thnig published. My gut feeling is that the situation is going to get much, much worse.
Nostalgia isn't what it used to be.