Melting Ice Cap : Effect? or Cause?
On a hot day in the summer, if we put a block of ice in the middle of our living room, it changes the temperature. That is, melting ice changes the temperature, it brings it down.
Now, some people seem to be getting it backwards and are saying that changing temperatures are causing the ice to melt, as in the case of ‘global warming’ and the polar icecap.
Which is it? We can’t have it both ways, … or can we?
The paradox is resolved if we take a closer look at how we use the notion of ‘cause’. If someone throws a lit cigarette into the forest and it goes up in flames, we say that that person ‘caused a forest fire’. But that’s a loose use of the word ‘cause’. The fact was that potential energy or ‘energy-of-place’ (in chemicals in the trees etc.) had built up to the point that the release of this energy could be easily ‘triggered’.
Since we normally talk about kinetic energy, the visible kind of energy that manifests when invisible potential energy is converted into kinetic energy and ignore the potential energy (the real source), … we get the sourcing of the dynamic backwards.
It would be interesting to compile a list of all those cases where we commonly get this backwards. Here’s a few. If anyone can think of any more, please pitch in!
- The melting ice caps cause a change in the ambient temperature (rather than vice versa) [temperature changes don’t melt Antarctic ice because its too bloody cold!]
- The excitement of the audience creates the celebrity (rather than vice versa)
- The laughter of the audience creates the successful comedian (rather than vice versa)
- The turbulence in the flow of the atmosphere causes the storm (rather than vice versa).
The general principle is that potential energy builds up in space (which is why it’s also called the ‘energy of place’) and its ‘release’ is ‘kinetic energy’ (energy of motion) which is visible. When we see this release of ‘kinetic energy’, we look for its cause ALSO in kinetic terms (i.e. a moving object), and we back up the film to find the local ‘kinetic’ causal agent who is ‘holding the smoking gun’. This sort of ‘causal agent’ merely triggers the release of potential energy, he/she/it does not ‘cause’ it.
The ‘celebrity’ and/or the ‘joke-teller’ does not have some ‘magic’ ‘action-at-a-distance’ powers to ‘cause’ the movement of hundreds of bodies in the audience, the audience has certain tensions in them (potential energies) which release when triggered, in the same way as avalanches are an accumulation of potential energy whose release is triggered by a skier.
We can’t see the buildup of potential energy or ‘tensions’ or ‘pressures’ so we don’t associate this with ‘cause’. Instead, we attribute ‘cause’ to whatever we can see, and what we can see is the ‘triggerer’ of the release of potential energies, whom we then label the ‘cause’ of the dynamics.
This doesn’t really work because, for example, the careless smoker who we say causes the forest fire can make exactly the same moves when the forest is sopping wet and nothing happens. Similarly, the temperature can change and the ice doesn’t melt (Antarctic ice is not melting even though the temperature is changing.). The joker can tell the same joke to a different audience and there are no laughs, the celebrity singer can sing to a different audience and the audience may not even pay attention to her. The storm can also ‘fizzle’ since the flow it is included in is the source of its forming and its strength.
So, in your own home, if you have a block of ice in the living room and it is melting you know it is changing the temperature in a moderating way and that seems good. But we all live in this space on the surface of the earth and if the great blocks of ice are melting, we also know it is changing the temperature in a moderating way, and why should that NOT be deemed good? It is just like the audience laughing, it is the relaxing of built-up tensions, … tensions between equatorial loading of the air with water vapour and polar extraction of water vapour from the air (all part of the moderating of thermal energy difference between equator and poles). Since water vapour is the most important ‘greenhouse gas’ and since the polar water vapour extraction system is ‘relaxing’ or ‘reducing inventory’ somewhat, perhaps this signals a net reduction in greenhouse gases.
Leaving these tricky points aside for the moment, … Any more candidates for the list?
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