Explaining Global Warming - A Junior High level science lesson

[Sal316]

(I wrote this and submitted it to the local paper. I got notice today that it'll probably be printed)

It's become inherently obvious that most people discussing GW on the 'internets' haven't the first clue about the science involved. Extremists in both camps have it wrong. GW does, in fact, exist, and no, it is not completely human caused. I don't know how many times and how many people have emphasized this point, but there are those who still refuse to listen.

So, as a scientist, and a chemist for the last 14 years, I was trying to think of a way to explain GW so that even the most scientifically inept could get it. This way, perhaps, we could get beyond the politics and actually discuss the issue rationally, logically, and factually.

I believe alot of the misunderstanding comes from the fact that people cannot grasp the concept of systems in equilibrium and cannot grasp the immensity of scale that is the global system. Too many times I've heard "Well, it snowed here in _________, so much for GW!" or "It snowed/rained/wasn't as hot this year so GW can't be real!" These statements come from scientifically myopic viewpoints. So, let's scale it down to something that people can conceptualize easier.

A fish tank.

The chemistry involved in the equilibrium in fish tanks is very similar to global chemistry.

There is a certain amount of O2 in the water in the tank. Fish swim through the water, use the O2, and 'exhale' CO2, we'll call this the 'human' contribution. Now, the water naturally absorbs CO2 at the surface. We'll call this the 'nature' contribution.

The fish tank also has a heater which regulates the water temperature (call this the sun).

Now, with filtering (charcoal, peat moss, aquatic plants) and reoxygenation through bubblers, the O2-CO2 balance is kept fairly steady. Now, as more fish are introduced and/or the current fish mature, the O2-CO2 system gets thrown out of balance because the filtering system can no longer exchange enough CO2 for O2. This is an effect similar to the Earth's population growth and the increase in the amount of the contribution due to the industrial sources.

What can be done to help this without removing fish or making the tank bigger?

Adding more plants (similar to reforestation)

Increase filtering capacity (similar to industrial exhaust scrubbers)

If nothing is done, the water will cloud up (pollution), the water temperature will rise, and the fish will die.

Alongside the O2-CO2 cycle, there is also the contribution of ammonia, nitrates, and nitrites from 'fish waste'. These chemicals affect the water's pH, which in turn affects the efficiency of the natural O2-CO2 cycle maintained by plants and filters.

Even without fish, the tank will eventually get fouled, as the Earth would even without human inhabitants. Call this 'natural' GW. However, without fish, the time for the tank to foul is substantially longer.

It is quite asinine to say that we can pump all of this pollution into the atmosphere and it has no effect on the globe.

It is also quite asinine to say that GW is all human caused.

The fact is, it's both.

We can't do much of anything to alter the natural global cycles. However, we CAN do things to minimize our effect on them.

Just like the fish tank, the Earth will eventually go through her cycle. As long as we continue to pump crap into our environment pretending everything is fine, the time between those cycles will become shorter and they'll become much larger in magnitude.

So I guess the question is......

Do you really want to wait until "the fish die" before admitting there's a problem?

[soothsayer]

1. good, but they prolly wish you'd used words other than 'asinine' and 'crap'

[Nihil]

2. Well done - just one nit to pick ...

> Even without fish, the tank will eventually get fouled, as the Earth
> would even without human inhabitants. Call this 'natural' GW. However,
> without fish, the time for the tank to foul is substantially longer.

This is glossing over the current situation in two ways:

1) The long-term (non-human) cycle also has its feedback mechanisms that
will "clear the tank" again on a similar scale - the fouling is not final.

2) The difference in timescale between the long-term (non-human) cycle
and the short-term (human caused) is of so many orders of magnitude as to
make such a comparison almost dishonest.

Although humans have had local (even regional) impacts in the past, it is
only over the last few centuries (maybe 300 years?) that the activity has
been so intense as to have a global effect and, given that humans have also
been actively removing the natural feedback mechanisms that would allow the
system to recover (albeit slowly), we are actually in uncharted territory.
(This does not mean "uncharted" in the sense of an absolute temperature
value or CO2 value but in terms of the rate of change of both ... the steep
gradients on the graphs over the last years are step functions when viewed
over geological timescales and the size of this particular step is still
to be determined: the foot is still plummeting down and yet to hit the floor.)

The combination of large positive change accelerators and the removal of
the normal negative change accelerators means that not only are we changing
at a far higher rate than ever before but that we have broken the braking
system that would have previously slowed & stopped the cycle in the past.
This is not a point to hand-wave away, even for the aim of "reaching more
of the general public".

Given the total lack of interest in changing the behaviour of the majority
of destructive humans, the only way that balance will be restored is when
the majority of destructive humans are killed. This should not be ignored
for the sake of "don't scare the sheep" but should be emphasised for the
slim hope that sudden, large-scale drastic change on a voluntary basis will
reduce the otherwise *unavoidable* alternative of a severe (5+ billion)
killoff.

Still, well done for writing the article and submitting it! :hi:

(Edited for clarification)

[Sal316]

3. I agree with your assessment.

My intention was to make the analogy as simple as possible without throwing in information that would confuse it. That's why I chose the fishtank analogy.

I agree that the differences between natural and human induced are on the level of orders of magnitude. I think most of the problem is the inability to grasp the concept in the first place, much less the influence of adding 'accelerators' and removing 'braking' devices. As a chemist, it frustrates the hell out of me to hear people try to talk about GW and not have the slightest grasp on the science involved.

So, in essence, I know it was simplistic, but that was kind of the point. To boil it down to the simplest of arguments and still have some scientific validity in the comparison.

Peace.

Christian

[jpak]

4. More nitpicking - there is no evidence that the recent warming trend is due to natural forcings

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