While the debate about Global Warming and it's causes has become more heated in recent months that doesnt always mean that there is a great deal more light being shed on the whole subject. One of the most infuriating things is reading comments by people who clearly haven't thought about the logic of what they are saying.
Reading the comments on Global Warming stories can be a particularly depressing experience when you see people taking strong stances on the basis of arguments which are sometimes so patently ludicrous that you wonder how the person failed to understand this.
I came across the following comment in an online newspaper today
"Despite any increase, carbon dioxide remains less than one percent of the greenhouse gas content of the atmosphere. Increases in carbon dioxide are more a symptom of a warming trend than a cause."
I'm sure my readers being the smart bunch that they are will immediately see at least one fallacy in this statement but I'll lay it out anyway because this argument is trotted out so often by Global Warming scpetics that it's become a bit of a mantra.
I dont know if you have ever heard of something called Ricin - if you havent then its basically one of the most poisonous substances known to man. At the present moment I am fairly safe in saying that if you are reading this then you have no Ricin in your body at the moment.
If you will allow me to then I will adminsister to you ( virtually of course) a dose which is so small that it will not amount to even a fraction of 1 percent of the weight of your body. Anyone who thinks the Global Warming scpetics argument is a logical one must of course accept that there can be danger in me giving them such a small dose of Ricin. After all its going to be much much less that 1% of their body mass - so why worry?
CO2 is indeed a small fraction of the atmosphere but it is clearly a fallacy to conclude from this that it cannot have major effects on the way the atmosphere works.
But that is not the only thing implied by the sceptics statement above. There is also the implication that not only is the total amount of CO2 in the atmosphere very small but that the changes to those levels that man is causing are a small amount of that already small fraction - so why worry? This also is illogical reasoning.
It is a trivial thing to find examples where a very small change in something can set off catastrophic changes. In nature there are many examples of state changes where only a very small change in for example the heat content of a material will lead to a sudden state change. As a more dramatic example consider (virtually) placing a small amount of high explosives in your basement. No problem there of course because the high explosive will only be a fraction of the volume of your house. Now we will apply a tiny increase in the energy of the high explosive. Here is the match. Just light it and apply it to the high explosive. I will be standing well back at the other end of the street of course. If you are a Global Warming sceptic who thinks that small increases in small things pose no dangers then I am sure you will be happy to stand there alone and apply the match yourself. No?