Ask HN: Simple experiments to demonstrate the “greenhouse effect”

Re:Ask HN: Simple experiments to demonstrate the “greenhouse... by pkt_nspktr on Sunday September 17, 2017 @08:58PM (#15272631)

Here's my gedanken experiment (caveat: I'm not an environmental scientist or engineer!): suppose you have a large box (closed system) with a large number of light bulb sockets and an infinite power source. Let a light bulb represent the amount of energy required by a person (i.e. home electricity, gasoline for travel, food for consumption, etc.). As the number of light bulbs increase within the box, the temperature rises. Regardless of other factors (e.g., CO2 emissions, energy sources) the transformation of fuel to energy, and energy to work, is not 100% and so there will always be waste heat produced.

One may use more energy efficient bulbs to maintain (or slightly decrease) the temperature within the box while increasing the number of bulbs. But savings from energy efficiency will be quickly spent as we add additional bulbs to the box.

I'll let the reader (experimenter?) draw her own conclusions about this thought exercise.

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Re:Ask HN: Simple experiments to demonstrate the “greenhouse... by tlb on Sunday September 17, 2017 @10:35PM (#15272967)

The effect of all our waste heat on earth's climate is insignificant -- thousandths of a degree. The greenhouse effect works in a completely different way, by CO2 reflecting infrared radiation that would otherwise transfer heat from the surface into space.

It's dangerous to promote incorrect ideas about how global warming works. For example, if global warming was just a problem of waste heat, we could shut everything off and things would be back to normal in a few days. But because it's caused by CO2 accumulating in the atmosphere, once we release CO2 it takes a long time (hundreds of years) for it to be re-absorbed by forests. People who saw these light-bulbs in a box might think that a quick solution is possible if warming gets out of hand.

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Re:Ask HN: Simple experiments to demonstrate the “greenhouse... by grizzles on Sunday September 17, 2017 @11:51PM (#15273280)

> If global warming was just a problem of waste heat, we could shut everything off and things would be back to normal in a few days.

Regardless of cause, the law of conservation of energy says otherwise. Also this isn't the type of law that congress can change.

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