"I know that for a couple of decades now, geologists, archaeologists and the like continue to search and present evidence of a geo-thermal event that is attributed to the extinction of the dinos. I think we're still in the theory state however. That's what I was getting at Tres."
I was not trying to be smartalec but it may have come across that way--sorry for that /forums/images/graemlins/smile.gif.
Anyway, the extinction of the dinos happened just a little bit /forums/images/graemlins/smirk.gif before the year 1816 or even before the end of the Plesitocene approx 20,000 years ago. The KT boundary is a thin layer present globally in sediments that can be correlated to be time equivelent and that is probably the result of a large asteroid impact approximately 65,000,000 years ago. That is 65 million. /forums/images/graemlins/shocked.gif. The Cretaceous at that layer ends and the Tertiary is considered to begin. This is not the first global die off, there have been others. Dinosaurs and many forms of life are significantly absent beyond the KT boundary. Geologist call the time we live in beginning with the end of the Pleistocene the "Recent" or Holocene.
There, as well, have been several glacial periods and interglacials other than the one we live in. The earths relatively recent climate has been punctuated by these "cycles". The persitent seeking of solar cycles, various sunspot theories and other cyclic or thought to be cyclic phenomena attributed to the cause of these glacial cycles by scientists at one time or another have been used as explanations. I am not a cycle person. Cycles are currently out of favor among many geologists etc. A while back a British scientist/philosopher proposed a controversial theory which likened the earth to a living organism complete with defense mechanisms, climate regulators etc. Some people, of course, took this thought train a wee bit far and even began proposing that the earth was alive (in a way it is) and that living organisms like humans were like viruses and disease/famine/climate change a defense mechanism. Now, that is out there on the edge /forums/images/graemlins/crazy.gif but if you leave off all the New Age crap it works a lot better for many scientists including me than cycles.
There is a tremendous amount of hysterisis or "boot strapping" in the global climate due to the buffering activity of the sea and living organisms, rock and the atmosphere and other stuff. That is why I find it really diffucult to attribute the very recent global rise in temp to the last 100 years of man's burning fossil fuels etc, a very tiny amountof time and a very tiny amount of gases produced. Especially when, with some noted exceptions, the global temps have been rising for the last 20,000 years or so more or less, gradually, slowly, some steps back but slowly an upward trend until yet again the earth heads back into another glacial episode. The climate is changing, duhhhhhhh, yeah, any more big news? /forums/images/graemlins/laugh.gif /forums/images/graemlins/tongue.gif and we humans will have to learn to adapt, we are good at it or we would never have made it out of the savanahs.
If we can quell our need to kill one another, the future really is bright. /forums/images/graemlins/cool.gif J
