Increased population is the cause of global warming

[Colibri]

@antechinus

The sugars and starches that humans grow (grains, potatoes, cane etc) and then burn up, absorb insolation via photosynthesis. Part of this light would otherwise be converted to heat. So wouldn’t these crops be cooling the planet down by locking up energy - temporarily.

Yes, this is related to my point in post #11. Plants are locking up part of the energy in sunlight as carbon compounds which would otherwise be converted to heat.

[Left_Hand_of_Dorkness]

@Chronos

No, it’s a power figure. Power per hour would be a most peculiar sort of unit, which I don’t think would have any sort of practical meaning. Power is already a per-time quantity, so 125 watts/person means that each person puts out 125 Joules of energy per second.

And human energy consumption is essentially identical to human heat production. Yes, we use some of our energy to move things around, but what do you think happens to that energy afterwards? Ultimately, everything ends up as heat, and it doesn’t even usually take all that long.

Hey, I told you I knew nothing about physics :). Thanks for the correction re: wattage!

As for the second point, I’m not really sure I understand this–but I think it may be more due to the incoherency of the body-heat theory than due to your answer or my comprehension. If, for example, we eat high-energy diets and lock our sewage up in underground vaults, aren’t we in the short term taking some measure of energy out of the system (or at least preventing it in the short term from contributing to global warming)?

Daniel

[wevets]

@Neurotik

I’ve always wondered about the spread of urban areas. Aren’t urban areas generally “hotter” than the surrounding surface?

Urban areas are hotter, which the political opponents of global warming hypotheses often cite as producing a false warming trend.

Oddly, they don’t seem concerned at all by data that shows the oceans, very few of which are paved ;), are getting warmer.

[Chefguy]

Physics was always my weakest coursework. Can one of you please collate this information into a single posting and put it in terms a dumbass like me can understand? Thanks.

[LiveOnAPlane]

OK, this is kind of simplistic, and I admit I am glossing over a lot of thermodynamics here, but here goes:

Planet Earth is pretty much a closed system. Not completely, of course, as it is powered by the sun, receives outside input from space objects such as meteors and such. But on earth, you have to consider that what each human radiates comes from “stuff” that that human has taken in from the system. To produce heat, each human consumes (and takes out of the system) energy. The energy has to come from somewhere.

So, for every watt produced by a person, a watt has been removed from earth’s system. (I know, I know, nothing is 100% efficient. I said I am simplifying and glossing over the details)

So in the long run, these things tend to even out.

Global warming is not caused by an excess of energy, but rather by us changing the recomposition of greenhouse gasses, which results in more outside heat being retained (assuming you adhere to the global warming theories). That, though, is a different matter entirely.

So, to rephrase/sum up: Go back to a single person. What goes in, comes out, and essentially balances.

[LiveOnAPlane]

P.S. Chefguy, you are not a dumbass, that was a decent question.