The contribution of metabolic heat to climate change.

[Shapedoctor]

Human beings are endothermic organisms that generate metabolic heat. That heat warms up the environment humans live in. The environment humans live in is the biosphere of planet Earth. Planet Earth is the globe that's referred to in the phrase "global warming".

Yes, we might be in a natural warming trend, but heat is cumulative. If there is a natural warming trend then we're adding ~6.5 billion human generated heat sources to something that's already warming up plenty on it's own.

I'm looking for one or more "certified" scientists to either confirm or discredit my statements. All relevant comments, questions, and/or links to related information will also be appreciated.

[freeztar]

It's insignificant when you take into account IR from sun rays.

Most of the world's populations live in the tropics. Their bodies are constantly trying to cool themselves because the air around their bodies is much hotter than the heat their bodies are generating.

[Shapedoctor]

Useless post so I can have a post count of 10 and post a reference link in the following post.

[Shapedoctor]

Originally Posted by freeztar

It's insignificant when you take into account IR from sun rays.

Most of the world's populations live in the tropics. Their bodies are constantly trying to cool themselves because the air around their bodies is much hotter than the heat their bodies are generating.

Thanks freeztar, but I'm not attempting to quantify significance at this time.

Second Law of Thermodynamics:

The second law states that heat energy cannot be transferred from a body at a lower temperature to a body with a higher one without the addition of energy. Thus, warm air outside can transfer its energy to a cold room, but transferring energy out of a cold room to the air outside requires extra energy (as with an air conditioner).

http://dictionary.reference.com/brow...Dictionary.com

It takes energy for people to keep cool in the tropics. That energy eventually becomes heat. In addition to this I don't think that many human beings live in places that have an average day & night temperature that's above body temperature. Even if they do it I don't believe it will excuse them from the second law.

[Zythryn]

Heat is not so much the issue as what happens to the heat as it rises through the atmospher? Can it esape, or is it trapped by greenhouse gases?

As for body heat of humans, don't forget to subtract the body heat of the creatures we have displaced and the ones we continue to drive to extinction.

I would suspect that our industrial heat waste is as much, if not more than simply our body heat.

[CraigD]

Human beings produce no more heat than is contained in the food they consume. For an average human, this is about 2000 kcal/day, or about 100 Watts. The current world population is about 6.5 billion, so the total rate of heat output for all of the human beings on Earth is about 660 GW ().

The total energy input of the Sun is . It varies by about 0.1% roughly every 11 years. (sources: wikipedia articles “Earth's energy budget” and “Solar variation”).

So the total heat output of all the human beings on Earth is about 0.04% that of the normal 11-year cycle of solar variation. In other words, for human beings to have the same impact on climate as the Sun’s slight 11-year cycle of variation, the population would have to be 2500 times greater, or about 16 trillion.

Based on this, I think “The contribution of [human] metabolic heat to climate change” is negligible.

[freeztar]

Originally Posted by Zythryn

As for body heat of humans, don't forget to subtract the body heat of the creatures we have displaced and the ones we continue to drive to extinction.

Not too mention all the cows and chickens we take out of the equation daily. (I know, I know...they're replaced)

I would suspect that our industrial heat waste is as much, if not more than simply our body heat.

Indeed.


@Shapedoctor
If you don't want to quantify significance, then you might find this more to your liking, a quantification of heat:
Human Heat Balance

Using an average from the variables and multiplying by estimated population size, one could figure out the total heat generated by humans worldwide.

But of course, there are other factors to consider...

Could it contribute significantly to global warming? Not imo. We're probaby doing much more harm by exhaling.
It would be interesting to see a comparison with, say, geothermal radiation, though.

[Shapedoctor]

Originally Posted by Zythryn

Heat is not so much the issue as what happens to the heat as it rises through the atmospher? Can it esape, or is it trapped by greenhouse gases?

As for body heat of humans, don't forget to subtract the body heat of the creatures we have displaced and the ones we continue to drive to extinction.

I would suspect that our industrial heat waste is as much, if not more than simply our body heat.

Thanks for they reply Zythryn.

I'm already assuming that global warming is taking place and I have a pretty good understanding of the greenhouse effect and the effects of human industry on our environment.

The challenge at hand is to figure out whether or not we contribute to global warming as animals. For simplicity let's assume that any animals we have displaced would have the same total metabolic effect on the environment that we have.

In other words, would a solitary human being living as an animal in the wild contribute to global warming to some degree? Again, I'm not looking to quantify that degree at this point and I don't want people saying it's not significant. Some amount of contribution either exists or doesn't.

[freeztar]

You beat me to it Craig!

But I was hoping that ShapePhD would work it out...

Nonetheless, those are great numbers to illustrate the point.

[CraigD]

Originally Posted by freeztar

It would be interesting to see a comparison with, say, geothermal radiation, though.

From the links in post #6, The Earth’s geothermal output is 23 TW (), about 35 times the heat output of all humans.