
Ask HN: Simple experiments to demonstrate the “greenhouse effect” - perpetualcrayon
My thinking on the subject of global warming recently has been like this:<p>It seems there is too much &quot;special interest&quot; skepticism in the way on both sides of the argument (understatement of the century?) to think any individual is going to feel they can make any progress by simply arguing the points &#x2F; counter-points of the argument.  It just makes people angry and is almost always counter-productive.<p>If one wanted to demonstrate in a cheap, relatively quick, imperfect but sufficient fashion that the &quot;greenhouse effect&quot; is a real thing, how would they go about doing that?<p>I&#x27;m thinking if elementary, middle, or high schools (after school programs?) could reproduce this simple experiment for small classes it could be a catalyst for changing the opinions of the masses on climate change.<p>PS.  My hope is this comment thread can remain civil.  ;)
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pkt_nspktr
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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tlb
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.

~~~
grizzles
> 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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titojankowski
Climate change must be felt to be understood.

Depends what you're trying to demonstrate. I think the greenhouse effect is
cool. Carbon dioxide is useful, it's just not in the right place.

How might we build a bunch of rooms with different amounts of carbon dioxide
in them. And big lamps. In the rooms with low carbon dioxide, it's cool. With
rooms with lots of carbon dioxide, it getd hotter and hotter.

Even a simple physicics simulator app would be cool, different ppm of carbon
dioxide, and showing the change/temperature stability. I remember fooling
around with a physics simulator as a kid, springs and boxes, then you hit go
and they all move with gravity. Power it with data from the open climate API
at [http://carbondoomsday.com](http://carbondoomsday.com)

Keep the ideas coming!

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mapster
i imagine you need to convey a few important things: (1) effect of CO2 on
atmosphere per what tlb said below and (2) magnitude of CO2 emissions (like
telling people 1 part per billion is a eyedrop of water into a swimming pool,
etc.)

