The real danger of global warming

July 4, 2006 | By | 7 Replies More

Let’s do a thought experiment.  Imagine there is a salad bowl sitting (upright) on your kitchen table.  Imagine, also, there is a marble resting in the bottom of the salad bowl.  If you slightly disturb the marble with your finger, the marble will roll around the bottom of the bowl.  If you disturb the marble a bit more, the marble will roll up the side of the bowl and then roll back down to the bottom.  In this situation, the marble is said to be in a “stable equilibrium,” because the marble remains inside the bowl (equilibrium) despite reasonable-sized disturbances.

Now, imagine removing the marble from the bowl, turning the bowl upside-down, and resting the marble on the flat base of the bowl.  Although the marble will remain within the boundary of the flat base (equilibrium), even a relatively small disturbance will roll the marble off the base, down the side of the bowl, across the kitchen table and onto the floor.  In this situation, the marble is said to be in “unstable equilibrium,” because of the tendency of the marble to roll (far) out of position with even a small disturbance.  Once on the floor, the marble is again in equilibrium:  it will stay on the floor unless some force lifts it back to the tabletop.

Now, let us consider global warming.  For tens of thousands of years (and perhaps much longer), our planet has maintained roughly the same average temperature.  Yes, there were a few ice ages, but the planet’s temperature eventually returned to the more moderate level that we have today.  Thus, despite disturbances toward cooler temperatures, our planet’s temperature has been in a “stable equilibrium.”

Global warming, however, represents a new challenge to our planet’s temperature-regulating system.  As our planet warms, glaciers (both on mountains and on the polar ice caps) melt.  As they melt, they shrink, exposing more of the earth’s dark surface.  As more of the earth’s dark surface is exposed, the planet absorbs more of the sun’s energy (because white glaciers reflected much of the sun’s energy, whereas the dark ground absorbs more of the sun’s energy).  As the planet absorbs more of the sun’s energy, it warms up…which, in turn, melts more glaciers…which, in turn, raises the temperature…which in turn melts more glaciers….

Here, of course, is the problem:  although our planet’s temperature-regulating system has shown stable equilibrium when the temperature turns colder, scientists don’t have any information about whether our planet’s temperature-regulating system will display stable or unstable equilibrium when the temperature turns warmer.  For all we know, our planet’s temperature might behave like the marble on the upside-down salad bowl:  forever running away from its current level.  The result:  temperatures that go higher and higher until all the glacers are melted, at which point the planet might establish a new equilibrium at a temperature much hotter than we have today.  And what might this cause?  We’ve already seen some of the end results:  increased coastal flooding, increased hurricane intensity, decreased inland rainfall (drought), decreased winter snowfall in the Rocky Mountains (a precursor to drought)…the list goes on.  Significantly, such a hotter global temperature might be a very stable equilibrium, such that even a total halt in the burning of fossil fuel might be insufficient to return the planet to its current temperature.

This is why scientists (and many others) are so concerned about global warming.  It isn’t just because of the small temperature rise they see today.  It’s because they simply don’t know if the planet’s temperature will adjust itself back to where it was before we began burning fossil fuel (stable equilibrium), or if the temperature will soar to a point of no return (unstable equilibrium).


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Category: Environment, Science, Statistics

About the Author ()

Grumpypilgrim is a writer and management consultant living in Madison, WI. He has several scientific degrees, including a recent master’s degree from MIT. He has also held several professional career positions, none of which has been in a field in which he ever took a university course. Grumps is an avid cyclist and, for many years now, has traveled more annual miles by bicycle than by car…and he wishes more people (for the health of both themselves and our planet) would do the same. Grumps is an enthusiastic advocate of life-long learning, healthy living and political awareness. He is single, and provides a loving home for abused and abandoned bicycles. Grumpy’s email: grumpypilgrim(AT)@gmail(DOT).com [Erich’s note: Grumpy asked that his email be encrypted this way to deter spam. If you want to write to him, drop out the parentheticals in the above address].

Comments (7)

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  1. Erich Vieth says:

    We don't really know whether we will cause a dangerous heating of our atmosphere as human activities dump more carbon into the atmosphere. There are two well promulgated models A) that nothing bad will happen (promulgated by FOX) and B) the Earth's atmosphere will heat up (promulgated by 928 recent studies conducted by highly trained atmospheric scientists). I'm still trying to decide which side has more credibility.

    Well . . . even if we assume that we are not certain that burning more fossil fuel will cause great damage to our (one and only) planet, we thus come to what appears to me to be the central issue: Who bears the burden of proof? A) The "experts" presented by FOX, who regularly claim that going into uncharted waters is not going to be any problem or B) 928 scientists who point to troubling evidence that there seems to be a tight correlation between fossil fuel use and rising atmospheric temperatures?

    I would put the burden on those who advocate the riskier behavior. What is riskier here? Not option B, because maintaining lower atmospheric CO2 has not historically proven to be any risk at all. Option A appears riskier to me because atmospheric CO2 has been demonstrated to be closely correlated to heating of the atmosphere.

    As we keep pumping more carbon into the atmosphere, there are actually two horrible possibilities, both of which are suggested by the term "unstable equilibrium." 1) a new stable average temperature range that is much hotter than the current average; or 2) the lack of any equilibrium at all–a dangerously erratic situation, a system so mathematically chaotic that forecasts are no longer possible.

  2. Erika Price says:

    It frightens me to hear some "experts" list off the short-term benefits of global warming, such as heavier rainfall in agricultural areas and cooling of some of the planet's less hospitable regions. We can adapt and benefit from global warming, they say. And while we do need to adapt to global warming, because we have done essentially irreparable damage, we need to slow the progression into a severe distubance as well.

  3. Heather says:

    Erich, your sarcasm on "who to believe" is amusing, and the fact the a lot of seemingly intelligent people still say "well, the findings/beliefs are mixed on the subject" really kills me.

    We do know about the ice ages and our earth's return to equilibrium. Wishful thinkers like to assume that global warming would have the same effect. The ice ages were a purely natural phenomenon though, global warming is not. It seems we have done every bit of it to ourselves, and nothing like this has occurred in history. In this day and age where nothing is new, that is a very scary thought. It is a complete unknown.

  4. Edgar Montrose says:

    Grumpypilgrim, I think that your first analogy, that of the upright salad bowl, actually covers the entire situation without having to switch to the inverted bowl to make the point. The earth seems to be a remarkably robust system, as if the sides of the bowl are very high so that it takes a huge perturbation of the marble before it goes over the edge. But once it does, it reaches a new equilibrium somewhere on the table, or the floor, or down the stairs. That is a nightmare scenario.

    I do have to play Devil's Advocate for a moment, though. I am thoroughly convinced that human activities have led to all of the global warming effects that have been mentioned. However, I also know that a single natural event, such as the eruption of a major volcano, impact of a large asteroid or comet, etc., can so greatly increase the amount of particulate matter in the atmosphere that albedo (reflectivity) increases sufficiently to cause significant global COOLING. I do not know how the relative magnitudes of these effects compare.

    Of course, the counter to my own argument is that it is absurd to have to rely upon a catastrophic natural event to counter the catastrophic results of human activity.

  5. Erich Vieth says:

    I realize that Bush is allegedly a man of faith.

    This is his chance to show that his faith can (finally) translate into something good. All he needs to do (see Edgar's post above) is to have his God hit us with a major volcano or a smallish asteroid every 10 years or so to counteract all that CO. This might entirely solve our energy problems, since we could then switch over to plentiful coal. Bush would be wise, though, to give us all some warning each decade (or whatever) so that we can step out of the way of each of these environmental "innoculations."

    I'd recommend that Bush set up a new Department of Faith-Based Science to handle the whole thing.

  6. Debra says:

    Earth's magnetic fields are in equilibrium within the solar system.Human activities have endangered this equilibrium. Scientists should seek knowledge rather then rely on their endless speculations.

  7. Dan Klarmann says:

    Debra is confused. Humans have undeniably and quite provably increased the carbon dioxide balance in our atmosphere. There is no measurable evidence that we've done anything noticeable to the overall magnetic field of our planet.

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