Craig,
Thank you very much for what you just wrote. I occasionally host (and research and produce) an environmental radio show, and the data about wildly-shrinking polar ice caps alone is simply stunning. I almost wouldn't even know where to begin, when confronted with such a "flat earth" mentality (with all due respect to Mr. Griz, and I leave it to better minds than mine to decide how much is "due...") and I am very grateful that you took a stab at it. You cited a very good source--I truly hope he reads it.
Mr. Griz, I want to give you just one example of why you should not be lulled into a false sense of security by that old saw that "global warming is really just the normal climactic cycling of the planet."
To do this, we have to discuss two concepts, briefly--the "albido effect," and "tipping points." They become relevant to the fact that a HUGE AMOUNT OF POLAR ICE IS DISAPPEARING.
"Tipping points" are easy to understand--imagine rocking a canoe back and forth, harder and harder. Eventually, you get to a point of no return, and a new equilibrium point is reached--upside down. The canoe is stable again--just not in a way that's comfortable or practical, for humans.
The "albido effect" is a little more complicated, but basically, it is the ability of a white ground cover, like snow and ice, to reflect the sun's light energy back into space. A white ground cover reflects (from memory here, so don't quote me) I believe 90% of the sun's energy back into space (less what gets trapped under the atmosphere/ozone layer, which isn't a huge amount).
(Because water is "dark," compared to ice, it absorbs the sun's heat, rather than bouncing back into space. A dark jacket is warmer in direct sunlight, all other things being equal, than a white jacket.)
A dark "ground" cover, like the oceans, ABSORBS most of the sun's energy. Different ground covers are assigned different "albido" values.
The albido values are actually measured in terms of fractions of a whole number, I believe. I don't have the actual albido values, but we can understand them easier by using percentages here, anyway. In other words, water only bounces 10% of the sun's energy back into space. The other 90% is absorbed into our environment, thereby raising global temps. Ice, on the other hand, bounces 90% of the sun's heat back into space (in rough terms).
So...Ice = Good (prevents global warming) and Water = Bad (contributes to global warming).
The "albido effect" works like this, re: tipping points:
In the past, with a healthy amount of polar ice cover, 90% of the sun's energy that hit those caps was bounced harmlessly back into space.
Now, however, we have MUCH less polar ice cover. Three years ago, a chunk the size of Rhode Island just broke off, broke up, and melted away. Go-n-e.
Since then, we've lost even bigger chunks.
So--ice reflects 90% of the sun's heat. Water absorbs 90% of the sun's heat.
Therefore, the less ice you have, the more of the sun's energy is absorbed into the environment, as opposed to bouncing harmlessly back into space.
Therefore, melting polar ice RAISES the Earth's temperature, by raising ocean temps.
Higher ocean temps then lead to MORE MELTING POLAR ICE.
THIS IS ACTUALLY A FEEDBACK LOOP, just like when the electric guitarist stands too close to the speakers. The screeching coming from the speaker is picked up by the guitar's electronic "pickups," and fed back through the amp, albeit at a louder volume than before. And the noise comes back out of the loudspeaker (even louder) and gets picked up, and AMPED UP in the same manner, until it comes out of the speaker EVEN LOUDER, until SCREEECH! and somebody pulls the jack out of the amp, or guitar.
Except it's with temperatures, not decibles.
And Al Gore's trying to pull the effing jack out of the amp, even as people laugh at him and say they can't hear anything.
Maybe they can't hear anything because they're already D-E-A-F?
ANYWAY....
More melted polar ice = Less Snow Cover, which = MORE SQUARE MILES OF OCEANS.
More square miles of oceans = MORE HEAT ABSORBED FROM THE SUN.
More heat in ocean water MELTS EVEN MORE ICE.
You see where this is going, right? It's a FEEDBACK LOOP, headed for a "tipping point."
Less ice = more heat-absorbing ocean acreage, and on and on. (Here, the "canoe is rocking ever more violently, and becoming unstable, approaching it's "tipping point.")
Eventually, A TIPPING POINT IS REACHED, after which, THERE IS NO RETURNING TO THE ORIGINAL EQUILIBRIUM POINT.
In other words, THE CANOE GETS CAPSIZED.
Putting this in thermal terms, just like a "runaway" wood stove, the Earth will continue to warm up, beyond what is acceptable to the species currently residing here. There is no more "brake" on the increasing temperatures, in the form of snow and ice, to bounce the sun's heat back into space.
Thus this warming cycle ACCELERATES.
I could link you to pictures of glaciers taken in the 1970's, that are NOW ENTIRELY TURNED INTO LAKES.
Thousands of square miles of what was glacier 30 years ago are now either black rock, dirt or water--all of which absorb WAY more heat than snow and ice.
Now, about the nonbelievers saying "this is all just part of a natural cycle"?
Well, ice core samples taken from this melting ice show that it hasn't been unfrozen in hundreds of thousands of years.
In other words--it didn't melt from some "normal cycle."
It melted because we are approaching a tipping point. Fast.
I hope this helped, a little.
Craig's way was much more efficient, and informative--I apologize to any who found this unwelcome.
Thank you, again, Craig, for having the courage of your convictions.
Peter
