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Re: Global Dimming

Started by daqua, 08/06/2008 06:26PM
Posted 08/06/2008 06:26PM Opening Post
Jim, I saw that show. As you say it was merely pointing out another phenomenon, global dimming, which although theorized, was difficult to confirm until the unfortunate events of 9/11. I did not see where scientists were trying to deny the existence of global dimming. One interesting conclusion was that if we try to reduce global dimming, we may, in fact increase global warming. What to do, what to do.

That global warming exists, there is no doubt. But whether the cause is human consumption of fossil fuels or a natural cycle, has not been adequately answered, in my opinion. Glaciers formed and covered most of North America and receeded without any human intervention several times in the last millinum. We need to understand that fact in relation to what is happening now with human intervention. The answer is not yet clear to me.

Perhaps the cycle of volcanic activity was responsible for the formation and recession of the glaciers. Is the volcano of human consumption equivalent to that of mother earth? Dunno.

Regardless of whether we are causing global warming or whether it is a natural occurrence, we should do everything possible to reduce our reliance on fossil fuels, if for no other reasons than being able to breathe clean air and to insure a more economically stable source of energy for the world.

Dom Q.
Posted 08/06/2008 09:51PM #1
Jim I'm not sure whether there is pony in the room or whether the room is just full of horses**t. I don't believe the politicians have got the message yet that the ordinary Joe is getting squeezed financially. To them suffering means flying home on weekends on a commercial airlines rather than a private jet. For the ordinary Joe it means going without needed medications to afford buying gas to go to work. We live a fantastic country that is being ruined by a bunch of greedy politicians. The part of me that is looking for the pony in a room full of horses**t hopes that the people can overcome the idiots. The part of me that says its just a room full of horses**t says it's to late greed has rigged the system
Posted 08/07/2008 04:19AM #2
Jim Babcock said "We all know the basics like filling our tires with air; we are not stupid and such statements enforce beliefs that those who make them are elitist jerks to ignore."

Well, Jim, you know it, and I know it, but...

[COLOR="Blue"]"Fully 27 percent of passenger cars on U.S. roadways are driven with one or more substantially under-inflated tires, according to a major survey conducted by the U.S. Department of Transportation’s National Highway Traffic Safety Administration (NHTSA).
Moreover, 32 percent of light trucks (including sport utility vehicles, vans and pickup trucks) are driven with one or more substantially under-inflated tires, according to the first study of its kind to be conducted by the government in two decades."[/COLOR]

It doesn't hurt to remind everyone else does it?
Posted 08/07/2008 07:37AM #3
That global warming exists, there is no doubt. But whether the cause is human consumption of fossil fuels or a natural cycle, has not been adequately answered, in my opinion.


The drivers of climate change, both natural and anthropogenic, can be summed and compared to the observed rise in global temperature. When all of the natural drivers are summed, and yes there are error bars associated with these, the result is a rise in temperature that is less than what is observed. When the natural drivers are added along with the radiative forcing of anthropogenic CO2, the predicted temperature matches, within error, the observed record. What this means is that there are natural drivers, but anthropogenic CO2 is contributing to global warming. The issue should not be polarized yet we often hear one side argue that the warming is entirely a natural cycle and others that it is entirely our fault. The climate system is more complex than that.


Glaciers formed and covered most of North America and receeded without any human intervention several times in the last millinum. We need to understand that fact in relation to what is happening now with human intervention. The answer is not yet clear to me.


The first sentence is wrong. The vast ice sheets that covered North America advance and retreat on orbital time-scales and not over the last 1000 years. In particular, there is a 100,000 year cyclicity. There are also ~21ka and ~41ka cycles. The driver of these cycles is orbital dynamics (precession of the equinoxes, obliquity (tilt) of the axis, and orbital eccentricity. The last ice sheet that covered North America reached a maximum ice volume around ~17,000-21,000 years ago and retreated around ~10,000 years ago. This period since ~10 ka is called the Holocene and is a period of relative climate stability that allowed human civilization to flourish. During the Holocene, particularly the late Holocene, smaller mountain glaciers have shown episodes of advance and retreat, but nothing like the great ice sheets. The cause of these shorter period fluctuations is not as well known, but there are both celestial and terrestrial drivers that contributed.

Perhaps the cycle of volcanic activity was responsible for the formation and recession of the glaciers. Is the volcano of human consumption equivalent to that of mother earth? Dunno.


NO NO NO!!! I knew we would be talking volcanoes again. The USGS showed that annual CO2 emissions from all volcanic and geologic CO2 sources is 130-230 million tonnes. Humans emit a staggering 27 billion tonnes. That means we emit ~150X more than volcanoes. Here is a USGS website to read: http://volcanoes.usgs.gov/Hazards/What/VolGas/volgas.html