The other global warming: (Waste heat)

[OKIsItJustMe]

http://www.boston.com/bostonglobe/ideas/articles/2009/01/25/the_other_global_warming/

The other global warming

Even if we contain the greenhouse effect, says a Tufts astrophysicist, we'll have another heat problem on our hands

By Bina Venkataraman | January 25, 2009

Human civilization will heat up the planet; the glaciers will melt and the seas will rise. It's a familiar refrain by now, with a familiar solution: stop pumping out the greenhouse gases that trap the sun's heat.

But even if we bring the greenhouse effect under control, says a Tufts astrophysicist, the earth will warm up anyway, thanks to a completely different source of heat that we create ourselves.

Over the next 250 years, calculates Eric J. Chaisson in a recent paper, the earth's population will start generating so much of its own heat - chiefly wasted from energy use - that it will warm the earth even without a rise in greenhouse gases. The only way to avoid it, he says, is to rethink how we generate energy.

His paper examines the planet's growing pool of waste heat, a widespread phenomenon that nonetheless has been little studied as a cause of climate change. Nearly everything that uses or generates energy - chiefly power plants, but also cars, snowblowers, computers, and light bulbs - squanders some energy as wasted heat. And the larger and more energy-hungry the human population grows, the more waste heat remains in our atmosphere.

…

[david13]

1. I think

that's true. The real problem is over population. And no one even speaks of it.
dc

[OKIsItJustMe]

2. Actually several people speak of it.

And somehow, they each seem to think they're the only one…

http://en.wikipedia.org/wiki/Population_bomb
http://en.wikipedia.org/wiki/Overpopulation
http://www.overpopulation.org/
http://www.overpopulation.com/
http://www.nationalgeographic.com/eye/overpopulation/overpopulation.html
http://www.cnn.com/2007/TECH/science/09/25/overpopulation.overview/index.html

[DCKit]

3. It's only "waste heat" because we don't use it.

Every power plant could be heating acres of greenhouses all winter or even towns with what they're throwing away. It's the infrastructure costs they don't want to cover.

[NickB79]

4. But the energy of that heat still escapes into the atmosphere eventually no matter how it's used

Say we run a power plant burning coal. It is roughly 30% efficient at converting heat to electricity. The other 70% of that energy is released into the environment as steam.

If we capture that steam and use it to heat greenhouses and surrounding buildings, that heat still gets released into the atmosphere as it escapes the buildings. Co-generation systems like this are highly efficient, but don't magically eliminate the heat pollution of the surrounding environment. It just gets more "bang for the buck" from each BTU of energy. It slows, but doesn't eliminate, the underlying issue outlined in the OP.

This article makes an interesting point. Even if we someone discovered fusion tomorrow, and it emits no GHG's, the planet would still warm. The electricity generated from a clean energy source like this would be used to power TV's, computers, electric cars, lights, etc. All of these technologies emit waste heat from resistance in the electrical components.

Infinite growth, even using clean and/or renewable resources, is simply not possible when stretched out to timescales of centuries.

[OKIsItJustMe]

9. OTOH, more efficient use of energy, with constant energy use

means less energy released into the atmosphere.

[.... callchet ....]

5. Could be about 50 billion people in the year 2300.

What about the consideration of the body heat from that many people?

[.... callchet ....]

6. Every gallon of gas burned in a car

could produce the same amount of power using the heat to run a steam engine in the car.

[NobleCynic]

7. I would think that the amount of extra heat generated

by human activity stemming from nuclear or fossil fuel sources would be too small by many many factors of magnitude to affect the climate. Albedo changes to the surface (paved roads and buildings, crops, and other infrastructure) along with changes to the atmosphere (GHGs) should dwarf any possible direct heating effect from entropy loss.

[GliderGuider]

8. This would be down near the bottom of my list of concerns

His outlook seems to be based on ignoring 90% of what's happening already to limit human growth and activity. IMO it's unlikely that more than a billion humans will see 2100, and equally unlikely that they will be producing much waste heat beyond campfires.

There are simply too many bullets speeding towards us simultaneously for us to have any realistic hope of dodging them all. Given that we are already bumping up against the limits to growth, Liebig's Law of the Minimum is likely to kick in for us sometime in the next decade. Combined with a sustained economic crash in a hyperpopulated, hyperactive, overly efficient, non-resilient civilization, the outcome is not likely favour a progression that would culminate in a world over-heated by human activity.

[Barrett808]

10. Word. n/t