Posted on 01/01/2009 7:03:46 PM PST by Shellybenoit
Click on POGW graphic for full GW rundown
Ping me if you find one I've missed.
Global Warming on Free Republic
Thanks for the ping.
Anyway, I clarified in my later posts above that I wasn't talking about punctuation -- transient cataclysmic events such as meteorite strikes that can cause huge temperature changes. I'm talking about warming or cooling trends that last for long enough to constitute -lasting- change. Transients can be spectacular, but they get integrated over time.
For example, looking at the chart on the page you referenced in your post:
> ...although the date cannot be known exactly, it is estimated from the annually-banded Greenland ice-core that the annual-mean temperature increased by as much as 10°C in 10 years.
Okay, let's agree it did that. Clearly something went nuts and temperatures rose dramatically and quickly.
But look at the overall temperature trend on that chart, starting at 16 thousand years ago. Draw a straight line from 16 thousand to 10 thousand, and you'll see that the temperature was trending upward, with two roughly equal abrupt increases at 14 and 12, and a decrease in between, such that the areas over and under the "trend" curve are nearly equal.
This suggests, to me at least, that there were multiple things going on. One is a trend lasting 5+thousand years, increasing temps; the others were transients. Spectacular transients, no doubt. The explanations proposed on the referenced page are mind-bogglingly cataclysmic. Yet even those did not affect the long-term trend, which recovered and continued.
Granted, one could also claim that the two spikes caused the upward trend. But then why did the first one at 16 thousand fall back at 12-13 to the same level, before rising again?
So we can agree that there are abrupt changes, presumably due to cataclysmic events. My claim is that "global climate change" is more about the long trends than the punctuation.
As to causes, the reference page states unequivocally that while there are proposed mechanisms, there is no clear agreement. (That doesn't detract one whit from the science, of course.)
I'm not prepared to agree with the AGW advocates that we are facing imminent disaster of cataclysmic proportions, whether natural or man-made. I don't think anything humans are doing can have that much effect globally, other than to make some of us less comfortable.
> It's always a good idea to have one's facts straight before declaring the ignorance of others.
I will endeavor to be more clear, thanks for the admonition.
If you have commentary on what I wrote above, have at it. Like I said, it isn't my field, and I may be misinterpreting what you tossed at me, in which case I'm happy to be corrected.
The vast majority of abrupt climate changes were preceded by millenial trends. This is exactly true of the Younger Dryas. The Earth was warming for thousands of years before the YD cooling event, which was initiated quickly by the thermohaline circulation cessation. The reason that the YD termination happened so quickly was that all of the other global factors (including, yes, rising atmospheric CO2) set up an even larger warming spike when the THC restarted.
I disagree - the gyrations over the last 2000 years have been of durations from two to three hundred to as short as 40 years (Dalton minimum). You may not see the temp changes of the Dalton Minimum as all that significant, but since we teter on the edge of glaciation, that minor change had serious impacts on those who lived through it (or died as a result).
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.