- If we find another advanced civilisation out there changes are they will be carbon based oxygen breathers like us. Gillet outlines several other possible bio chemistries but all of them seem to be hostile to getting to the advanced phase because they either preclude the existence of fire, damage metals too quickly or both.
- In geological time Ice caps on earth have been the exception not the rule.
On the whole however Since the age of the Dinasours the Earth has gotten colder and is still colder. One reason is that the atmospere has thinned somewhat. There are fossils of Dragonfiles with a wingspan of over a foot.
Such a creature could not exists in the current atmospere, it would suffocate. Likewise the flying reptiles with wingspans equivelent to a small plane would not be able to generate sufficent lift in one atmospere to get anywhere. All of the dinasours would find the present world much too cold for them.
Another little tidbit is that CO2 is nothing compared to Water vapor when it comes to global warming. All in all the case for saying that we are making things get hotter seem rather thin on the ground. And here's another question if we shift to using hydrogen fule and start spewing extra watervapor into the atmospere at the same rate as we are currently unlocking carbon what effect will that have? If the water vapor stays up there for any length of time it could cause more warming instead of less. Recently some scienists worked out that Bio fules acrually cause more polution then fossil fules when you factor all the steps in, so it is a question worth asking.
Reducing pollution is a good thing, and I wouldn't argue against it, but reallistically speaking reducing pollution won't stop climate change. Simply because the Climate changes, it always has and it always will.
Reduce polution by all means, and perhaps you can slow down the warming a fraction, but I suspect that it will still happen regardless of what we do. And the truth is climate change is going to be inconvenient for our species no matter which way it goes.
If it gets hotter then small ilands submerge and the ideal farming zones shift (and possibly shrink). If things go the other way, (and every full blown iceage has been proceeded by a sharp temperature spike). Then good chunks of continental Europe and North America could end up under glaciers again. The population affected is probably a lot greater then in the warming senario.
In either case habitats change accross the world and overly specilised animals die out in the wild.