Energy is never destroyed, right?

[BeFree]

Energy is, in simple terms: heat.

So here's a thought re: Global Warming

As we take fuel out of the ground via fossil fuels, and strip energy from it, creating heat in a new space - the atmosphere - are we not directly warming the atmosphere?

Much the same as heating a room, just on a larger scale.

Thoughts?

[WHEN CRABS ROAR]

1. Energy is never destroyed, but it might not be able to be

measured as to what it was transformed into and it is not always heat.

[BeFree]

2. well

For every action there is an equal and opposite, right?

And, of course, we are stripping solid materials out of the ground that are in a compact, condensed form, altering the composition of said materials and greatly disbursing that material into the atmosphere.

So what would be the opposite to that action?

[WHEN CRABS ROAR]

4. I am energy and when I decompose into the earth

I will provide a new energy for what ever uses it. Many forms of energy.

[TheWraith]

3. Yes, we are.

Burning fossil fuels directly creates waste heat. So too does most use of energy: for instance, waste heat is produced burning gas for electricity, again when transmitting that energy across the countryside, and yet again using that transmitted energy to run, say a computer. So almost every aspect of human civilization is generating heat, which is radiated into the atmosphere. Although in terms of global warming, the amount of "pure" waste heat produced by human civilization is relatively small in comparison to the increase in solar heat being trapped by atmospheric CO2.

[petronius]

5. Yes, but there is a big difference in scale. The total amount of energy in a year's

production of crude oil is only about 0.004% of the amount of sunlight absorbed by the Earth's surface over the course of a year. So even if all that energy was converted solely to sensible heat it wouldn't be a big player in global temperature.

Locally, however, it may be a different story. It wouldn't surprise me if waste heat from transportation and energy production was a non-trivial contributor to urban heat islands for example...

[BadgerKid]

6. Well, the Earth is an open system

With respect to energy. The by-products of human activities (carbon dioxide and water) helps to trap more solar radiation, but more water vapor in the atmosphere can reflect more solar radiation. I don't have the numbers in front of me, but they should be wikipediable or googleable.

[badtoworse]

7. The earth is not a closed system

Substantial amounts of sensible heat get radiated into space on clear nights. I agree with other posters that insolation is, by far, the greatest source of thermal energy to the atmosphere.

[BeFree]

8. So, I wonder

How much heat released at sea level actually makes its way into space? Being that there is a very cold layer of air which it must pass through first, it doesn't seem likely that much surface heat rises to space.

And, of course, when the ocean heats up and expands, that causes ice to melt and sea level rise to occur.

[badtoworse]

10. It doesn't really matter...

As pointed out elsewhere on the thread, the heat released from man-made sources (combustion of fuels, friction, etc.) is insignificant compared to the amount of heat absorbed from the sun. The problem is that atmospheric changes caused by the combustion of fossil fuels reduce the amount of energy that the earth radiates back into space. If the amount of energy absorbed from the sun stays relatively constant (it actually does vary in cycles, but let's ignore that for now)and the heat rejected (radiated) back into space is reduced, then a simple energy balance tells you that the temperature of the earth is going to rise.

[joshcryer]

12. Indeed, the entire waste heat contribution is smaller than solar variation!

(Solar variation over the same time period.)

[BeFree]

15. well

we are talking different levels of heights and travel times of reflection.

Can heat from the sea level make it into space? And if so how long would the travel take?

At heights, the reflection into space is quick as there is little space to move through.
But from sea level there is much to get around before escape.
And heat transfer is relatively slower from oceans than from air.

Could be we are putting a lot of waste heat into the oceans?

[joshcryer]

17. No. Waste heat is 1/80th GHG forcing:

http://mustelid.blogspot.com/2005/04/global-warming-is-not-from-waste-heat.html

Not knowing this it's easy enough to be lied to and told that waste heat causes AGW, but yeah.

[joshcryer]

18. Here's a redux of the argument:

http://mustelid.blogspot.com/2005/05/global-warming-is-not-from-waste-heat.html

It's easy enough to disprove that thermal heating has caused the measured warming on the planet: solar variance is several times more powerful than thermal heating to date.

[petronius]

14. Energy leaves the planet to space in the form of radiation, which is emitted

by the surface and atmosphere. The type and amount of radiation given off by something is determined by its temperature, and as materials warm they emit more radiant energy.

So, it's not really a process of heat (thermal energy) rising out of the atmosphere to space but rather the propagation of electromagnetic energy upward. Anthropogenic energy released into the lower atmosphere would be dealt with the same way, but it's a tiny tiny fraction of the whole cascade. More important with fossil fuels is the release of gases into the atmosphere that absorb some of that outgoing radiation, leading to the trapping of additional energy near the surface (that's global warming)...

[BeFree]

16. As they warm or as they cool?

I here thought is that as something absorbs radiation it heats up, and as it cools down it emits radiation.

Example: The oceans absorb radiation and heat up, and as oceans cool it is releasing that radiation.

[petronius]

19. Both, actually. Objects are giving off radiation all the time, and the output

at a given moment is determined by the temperature. So, a hot object gives off more radiation than a cooler object.

The net radiation determines how temperature changes: if more radiation is absorbed than is emitted the object will warm. If it emits more than it absorbs, it will cool. (Ignoring conduction and other pathways, of course.)

For example, imagine a parking lot surface at 11 am - it's pretty warm, so it gives off a lot of energy, but the amount of sunlight it's receiving is even greater, so it continues to heat up. At 11 pm, that surface is cooler than it was during the day, so it emits less radiation. But, it's not receiving any sunlight and only a little downward radiation from the atmosphere, so it continues to cool...

[badtoworse]

20. Look up "Stefan-Boltzmann Law"

Here's a link to start:

http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law

[joshcryer]

9. Any heating contribution by industrial society is quickly negated by large volcanic eruptions.

It just takes 50-100 years but all waste heat generated by our civilization to date is very very rapidly negated by such events.

[BeFree]

11. Eh?

I like to express our direct impact as equivalent to one large volcanic eruption each and every day.
Whether it is equivalent is a matter for math, but common sense seems to corroborate.
Add up all the smokestacks, tailpipes, etc. Each and every day. It is a lot.

[joshcryer]

13. I'm talking a Pinatubo style eruption.

Such eruptions add to the overall reflectivity of the planet and cool it to an extent, this allows the energy balance of the planet to go down, and negates waste heat contribution or even albedo change contributions.