The Scientific Global Warming Debate.

Abaddon

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To enter this discussion lets agree that the environment is changing, changing more rapidly than any previous period we have records from.

Global warming is happening.

The discussion is WHY it is happening.


Is it due to human action?, [wiki=http://en.wikipedia.org/wiki/Milankovitch]Natural Cycles[/wiki]?, a combination of the two? Something else?
 
I'd reckon human action. Some in the geological community is already championing the idea of the Anthroposcene as a geological time age.
 
Yes I heard of the idea of giving "us" an era. Kinda cool and saddening at the same time.

Carbon emmisions? CFC's? Ozone layer, Destroying the Amazon, Destroying Europes forrests thousands of years ago..which is worst?
 
Global warming can also be the result of a natural cycle as well. While it's not certain, it's possible that Earth was recently in a minor ice age. Thus any recent temperature increases observed can be accounted for by a natural cycle. Of course this argument is rather difficult to prove and doesn't quite fit in to your definition of "unnatural way."
 
Ah yes, I have restricted things some.. i didnt mean to completly.. i'll edit the OP
 
There is some possibility that the Earth's surface may be recieving more heat from sun.

1. the van allen radiation belty may have or may be weakening
2. Every so often the sun will produce extra amounts of heat fro a duration of time, more solar flares and such.

also I feel it is odd that when a debate about global warming arise nobody brings up the fact that the earth is being heated up thermal pollution.
 
any heat produced from cumbustion. or heat wasted from electrical transfers which intern realeases heat into the enviroment.

even we as animals release excess heat into the surroundings when we burn calories.

so driving your car produce excess heat which warms atmosphere, etc.

I have never seen any numbers that project how much are planet is warmed from thermal pollution, but i think we produce enogh heat to add a measurable amount to the gobal warming trends.

I know it does not sound like much, but think of it as a "penny save a penny earned" times 6.5 billion people times 360 days.
 
OP more discussion friendly
 
But if you're going to include thermal pollution, shouldn't you also include thermal dissipation? Granted the atmosphere does a pretty good job of keeping heat in but there's a non-negligible amount of heat that dissipates out into space too.
 
any heat produced from cumbustion. or heat wasted from electrical transfers which intern realeases heat into the enviroment.

even we as animals release excess heat into the surroundings when we burn calories.

so driving your car produce excess heat which warms atmosphere, etc.

I have never seen any numbers that project how much are planet is warmed from thermal pollution, but i think we produce enogh heat to add a measurable amount to the gobal warming trends.

Citys tend to be 2/3 degrees C warmer due to all the human efforts. Office heating, cars, people etc etc
 
i would assume that the dissipation of heat back into space would be calculated in with this aswell, but because of green house gases more heat is kept in our atmosphere.

I find cities to be cooler in the winter (but my house is surrounded by evergreen trees so..), air conditioners use heat pumps so the only true thermal pullution is the heat energy released from the pump.

My complaint about "global warming" is that it is only being compared to CO2, and when convient CH4. I doubt the legitamcy of some of the people whom make claims in this and, I am left to wonder how much money do they have invested in green technologies.
 
I quote this to be mean: :hammer2:
I find cities to be cooler in the winter



My complaint about "global warming" is that it is only being compared to CO2, and when convient CH4. I doubt the legitamcy of some of the people whom make claims in this and, I am left to wonder how much money do they have invested in green technologies.

What about temperature readings? Rainfall? Timing of El Nino, Ice cap reduction? Groundhog's? etc
 
Question about greenhouses trapping heat:

So if I understand correctly, solar heat comes into the Earth and is trapped inside the atmosphere by greenhouse gases. How is it that the greenhouse gases trap heat? If the system looks like:

Earth ----- atmosphere ---- outer space

What's to keep the heat from radiating to outer space instead of back to Earth? As I understood thermodynamics, heat flows to colder regions. Since outer space is colder, shouldn't the heat "trapped" by the atmospheric greenhouse gases permeate outwards rather than inwards?
 
Wavelength.


Solar heat is shortwavelenght and passes through readily.
Radiated heat from earth is longwavelenght and is reflected.

 
Reflection doesn't fully capture what I'm asking though. So IR is released by the surface and it goes back towards the atmosphere. It runs into the atmosphere but the atmosphere can release the heat in any direction. Why back towards the earth instead of towards outer space? This shouldn't have anything to do with wavelength. Or is it because I'm not properly distinguishing between radiation, convection, and conduction?

edit: grammar error
 
I am going to try to find something to support what I said early syhue, but it is time for me to sleep.

I'l go ahead and say where im going to look

greenhouse gases effect of radiant energy, and convection energy.


you've got me cornered here and im not sure if im going to be able to find my way out or not, we'll see tomorow.
 
Reflection doesn't fully capture what I'm asking though. So IR is released by the surface and it goes back towards the atmosphere. It runs into the atmosphere but the atmosphere can release the heat in any direction Why back towards the earth instead of towards outer space? This shouldn't have anything to do with wavelength. Or is it because I'm not properly distinguishing between radiation, convection, and conduction?

The atmostphere does not chose to realease it in any direction.

When the wave hits the atmostphere it can either bounce back, or pass through.

The shortwaves coming in pass through
The longwaves from earth, are more likely to bounce back.


Simple maths:

3 waves coming in, all get through.

Earth then releases these three

2 escape back to space, one bounces back (earth +1)

3 more waves come in

Earth releases these three

2 escape, one bounces back (earth +2)

repeat infinite and earth +many!


Basically the greenhouse effect means its is easier for heat to get in than out, and so it is building up.
 
I don't think we're on the same page here Abaddon. I'm questioning why the longwave is bounced back instead of passed through. What's so different about the shortwave that it passes through? Is it because UV can cause a cascading reaction in the ozone layer to pass through the energy but IR is too low energy to start a cascading reaction out of the atmosphere?
 
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