Global warming

The Cardinal - Archbishop of Sydney, Australia writes about the current concern over global warming:

Global warming doomsdayers were out and about in a big way recently, but the rain came in Central Queensland and then here in Sydney. January also was unusually cool.
We have been subjected to a lot of nonsense about climate disasters as some zealots have been painting extreme scenarios to frighten us. They claim ocean levels are about to rise spectacularly, that there could be the occasional tsunami as high as an eight story building, the Amazon basin could be destroyed as the ice cap in the Arctic and in Greenland melts.
An overseas magazine called for Nuremberg-style trials for global warming skeptics while a U.S.A. television correspondent compared skeptics to “holocaust deniers”.
A local newspaper editorial’s complaint about the doomsdayers’ religious enthusiasm is unfair to mainstream Christianity. Christians don’t go against reason although we sometimes go beyond it in faith to embrace probabilities. What we were seeing from the doomsdayers was an induced dose of mild hysteria, semi-religious if you like, but dangerously close to superstition.
I am deeply skeptical about man-made catastrophic global warming, but still open to further evidence. I would be surprised if industrial pollution, and carbon emissions, had no ill effect at all. But enough is enough.
A few fixed points might provide some light. We know that enormous climate changes have occurred in world history, e.g. the Ice Ages and Noah’s flood, where human causation could only be negligible. Neither should it be too surprising to learn that the media during the last 100 years has alternated between promoting fears of a coming Ice Age and fear of global warming!
Terrible droughts are not infrequent in Australian history, sometimes lasting seven or eight years, as with the Federation Drought and in the 1930s. One drought lasted fourteen years.
We all know that a cool January does not mean much in the long run, but neither does evidence from a few years only. Scaremongers have used temperature fluctuations in limited periods and places to misrepresent longer patterns.
The evidence on warming is mixed, often exaggerated, but often reassuring. Global warming has been increasing constantly since 1975 at the rate of less than one fifth of a degree centigrade per decade. The concentration of carbon dioxide increased surface temperatures more in winter than in summer and especially in mid and high latitudes over land, while there was a global cooling of the stratosphere.

I totally agree with the Cardinal's point of view. First of all, it seems clear that global warming is taking place. Secondly, it is not clear what the cause of that warming is. We know that global warming has taken place in the past. The warming that brought the end of the last ice - age is an example. So, it is not clear that human activity is a significant cause of this warming. Was the last ice-age actually brought to an end by the fires of a few cave men and, of course, herds of flatulent mastadons? Of course, controlling carbon dioxide emissions is not a bad idea in any case. Just don't go all crazy about it. Thirdly, the so called "experts" don't always know what they are talking about. For example, when I began teaching about these things in high school social studies classes in the mid 1970's the experts said that the worry was over a coming global ice age. By the way, the experts also seriously missed the mark with their predictions about a population crisis. Finally, the Kyoto Accord, which some people treat as if it were Sacred Scripture, seems to be a remarkably useless document. The two most populous countries on earth (and the two with rapidly growing economies) (that's China and India of course) are not subject to the Accord. The defenders of the accord say this is because the accord would harm those two developing economies yet at the same time they argue that the harm to already developed economies is acceptable. I don't know. I do think that the Cardinal's advice about being calm and rational about these things is good. And besides, you couldn't prove global warming from the winter we've had in these parts.